diff options
40 files changed, 298 insertions, 693 deletions
diff --git a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.html b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.html index e4d94fba6c89..8d21af02b1f0 100644 --- a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.html +++ b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.html @@ -485,13 +485,13 @@ section that the grace period must wait on. noted by <tt>rcu_node_context_switch()</tt> on the left. On the other hand, if the CPU takes a scheduler-clock interrupt while executing in usermode, a quiescent state will be noted by -<tt>rcu_check_callbacks()</tt> on the right. +<tt>rcu_sched_clock_irq()</tt> on the right. Either way, the passage through a quiescent state will be noted in a per-CPU variable. <p>The next time an <tt>RCU_SOFTIRQ</tt> handler executes on this CPU (for example, after the next scheduler-clock -interrupt), <tt>__rcu_process_callbacks()</tt> will invoke +interrupt), <tt>rcu_core()</tt> will invoke <tt>rcu_check_quiescent_state()</tt>, which will notice the recorded quiescent state, and invoke <tt>rcu_report_qs_rdp()</tt>. @@ -651,7 +651,7 @@ to end. These callbacks are identified by <tt>rcu_advance_cbs()</tt>, which is usually invoked by <tt>__note_gp_changes()</tt>. As shown in the diagram below, this invocation can be triggered by -the scheduling-clock interrupt (<tt>rcu_check_callbacks()</tt> on +the scheduling-clock interrupt (<tt>rcu_sched_clock_irq()</tt> on the left) or by idle entry (<tt>rcu_cleanup_after_idle()</tt> on the right, but only for kernels build with <tt>CONFIG_RCU_FAST_NO_HZ=y</tt>). diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-invocation.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-invocation.svg index 832408313d93..3fcf0c17cef2 100644 --- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-invocation.svg +++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-invocation.svg @@ -349,7 +349,7 @@ font-weight="bold" font-size="192" id="text202-7-5" - style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_check_callbacks()</text> + style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_sched_clock_irq()</text> <rect x="7069.6187" y="5087.4678" diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg index acd73c7ad0f4..2bcd742d6e49 100644 --- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg +++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg @@ -3902,7 +3902,7 @@ font-style="normal" y="-4418.6582" x="3745.7725" - xml:space="preserve">rcu_check_callbacks()</text> + xml:space="preserve">rcu_sched_clock_irq()</text> </g> <g transform="translate(-850.30204,55463.106)" @@ -3924,7 +3924,7 @@ font-style="normal" y="-4418.6582" x="3745.7725" - xml:space="preserve">rcu_process_callbacks()</text> + xml:space="preserve">rcu_core()</text> <text style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier" id="text202-7-5-3-27-0" @@ -3933,7 +3933,7 @@ font-style="normal" y="-4165.7954" x="3745.7725" - xml:space="preserve">rcu_check_quiescent_state())</text> + xml:space="preserve">rcu_check_quiescent_state()</text> <text style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier" id="text202-7-5-3-27-0-9" @@ -4968,7 +4968,7 @@ font-weight="bold" font-size="192" id="text202-7-5-19" - style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_check_callbacks()</text> + style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_sched_clock_irq()</text> <rect x="5314.2671" y="82817.688" diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-qs.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-qs.svg index 149bec2a4493..779c9ac31a52 100644 --- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-qs.svg +++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-qs.svg @@ -775,7 +775,7 @@ font-style="normal" y="-4418.6582" x="3745.7725" - xml:space="preserve">rcu_check_callbacks()</text> + xml:space="preserve">rcu_sched_clock_irq()</text> </g> <g transform="translate(399.7744,828.86448)" @@ -797,7 +797,7 @@ font-style="normal" y="-4418.6582" x="3745.7725" - xml:space="preserve">rcu_process_callbacks()</text> + xml:space="preserve">rcu_core()</text> <text style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier" id="text202-7-5-3-27-0" @@ -806,7 +806,7 @@ font-style="normal" y="-4165.7954" x="3745.7725" - xml:space="preserve">rcu_check_quiescent_state())</text> + xml:space="preserve">rcu_check_quiescent_state()</text> <text style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier" id="text202-7-5-3-27-0-9" diff --git a/Documentation/RCU/Design/Requirements/Requirements.html b/Documentation/RCU/Design/Requirements/Requirements.html index 9fca73e03a98..5a9238a2883c 100644 --- a/Documentation/RCU/Design/Requirements/Requirements.html +++ b/Documentation/RCU/Design/Requirements/Requirements.html @@ -3099,7 +3099,7 @@ If you block forever in one of a given domain's SRCU read-side critical sections, then that domain's grace periods will also be blocked forever. Of course, one good way to block forever is to deadlock, which can happen if any operation in a given domain's SRCU read-side critical -section can block waiting, either directly or indirectly, for that domain's +section can wait, either directly or indirectly, for that domain's grace period to elapse. For example, this results in a self-deadlock: @@ -3139,12 +3139,18 @@ API, which, in combination with <tt>srcu_read_unlock()</tt>, guarantees a full memory barrier. <p> -Also unlike other RCU flavors, SRCU's callbacks-wait function -<tt>srcu_barrier()</tt> may be invoked from CPU-hotplug notifiers, -though this is not necessarily a good idea. -The reason that this is possible is that SRCU is insensitive -to whether or not a CPU is online, which means that <tt>srcu_barrier()</tt> -need not exclude CPU-hotplug operations. +Also unlike other RCU flavors, <tt>synchronize_srcu()</tt> may <b>not</b> +be invoked from CPU-hotplug notifiers, due to the fact that SRCU grace +periods make use of timers and the possibility of timers being temporarily +“stranded” on the outgoing CPU. +This stranding of timers means that timers posted to the outgoing CPU +will not fire until late in the CPU-hotplug process. +The problem is that if a notifier is waiting on an SRCU grace period, +that grace period is waiting on a timer, and that timer is stranded on the +outgoing CPU, then the notifier will never be awakened, in other words, +deadlock has occurred. +This same situation of course also prohibits <tt>srcu_barrier()</tt> +from being invoked from CPU-hotplug notifiers. <p> SRCU also differs from other RCU flavors in that SRCU's expedited and diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt index 55918b54808b..a41a0384d20c 100644 --- a/Documentation/RCU/torture.txt +++ b/Documentation/RCU/torture.txt @@ -10,173 +10,8 @@ status messages via printk(), which can be examined via the dmesg command (perhaps grepping for "torture"). The test is started when the module is loaded, and stops when the module is unloaded. - -MODULE PARAMETERS - -This module has the following parameters: - -fqs_duration Duration (in microseconds) of artificially induced bursts - of force_quiescent_state() invocations. In RCU - implementations having force_quiescent_state(), these - bursts help force races between forcing a given grace - period and that grace period ending on its own. - -fqs_holdoff Holdoff time (in microseconds) between consecutive calls - to force_quiescent_state() within a burst. - -fqs_stutter Wait time (in seconds) between consecutive bursts - of calls to force_quiescent_state(). - -gp_normal Make the fake writers use normal synchronous grace-period - primitives. - -gp_exp Make the fake writers use expedited synchronous grace-period - primitives. If both gp_normal and gp_exp are set, or - if neither gp_normal nor gp_exp are set, then randomly - choose the primitive so that about 50% are normal and - 50% expedited. By default, neither are set, which - gives best overall test coverage. - -irqreader Says to invoke RCU readers from irq level. This is currently - done via timers. Defaults to "1" for variants of RCU that - permit this. (Or, more accurately, variants of RCU that do - -not- permit this know to ignore this variable.) - -n_barrier_cbs If this is nonzero, RCU barrier testing will be conducted, - in which case n_barrier_cbs specifies the number of - RCU callbacks (and corresponding kthreads) to use for - this testing. The value cannot be negative. If you - specify this to be non-zero when torture_type indicates a - synchronous RCU implementation (one for which a member of - the synchronize_rcu() rather than the call_rcu() family is - used -- see the documentation for torture_type below), an - error will be reported and no testing will be carried out. - -nfakewriters This is the number of RCU fake writer threads to run. Fake - writer threads repeatedly use the synchronous "wait for - current readers" function of the interface selected by - torture_type, with a delay between calls to allow for various - different numbers of writers running in parallel. - nfakewriters defaults to 4, which provides enough parallelism - to trigger special cases caused by multiple writers, such as - the synchronize_srcu() early return optimization. - -nreaders This is the number of RCU reading threads supported. - The default is twice the number of CPUs. Why twice? - To properly exercise RCU implementations with preemptible - read-side critical sections. - -onoff_interval - The number of seconds between each attempt to execute a - randomly selected CPU-hotplug operation. Defaults to - zero, which disables CPU hotplugging. In HOTPLUG_CPU=n - kernels, rcutorture will silently refuse to do any - CPU-hotplug operations regardless of what value is - specified for onoff_interval. - -onoff_holdoff The number of seconds to wait until starting CPU-hotplug - operations. This would normally only be used when - rcutorture was built into the kernel and started - automatically at boot time, in which case it is useful - in order to avoid confusing boot-time code with CPUs - coming and going. - -shuffle_interval - The number of seconds to keep the test threads affinitied - to a particular subset of the CPUs, defaults to 3 seconds. - Used in conjunction with test_no_idle_hz. - -shutdown_secs The number of seconds to run the test before terminating - the test and powering off the system. The default is - zero, which disables test termination and system shutdown. - This capability is useful for automated testing. - -stall_cpu The number of seconds that a CPU should be stalled while - within both an rcu_read_lock() and a preempt_disable(). - This stall happens only once per rcutorture run. - If you need multiple stalls, use modprobe and rmmod to - repeatedly run rcutorture. The default for stall_cpu - is zero, which prevents rcutorture from stalling a CPU. - - Note that attempts to rmmod rcutorture while the stall - is ongoing will hang, so be careful what value you - choose for this module parameter! In addition, too-large - values for stall_cpu might well induce failures and - warnings in other parts of the kernel. You have been - warned! - -stall_cpu_holdoff - The number of seconds to wait after rcutorture starts - before stalling a CPU. Defaults to 10 seconds. - -stat_interval The number of seconds between output of torture - statistics (via printk()). Regardless of the interval, - statistics are printed when the module is unloaded. - Setting the interval to zero causes the statistics to - be printed -only- when the module is unloaded, and this - is the default. - -stutter The length of time to run the test before pausing for this - same period of time. Defaults to "stutter=5", so as - to run and pause for (roughly) five-second intervals. - Specifying "stutter=0" causes the test to run continuously - without pausing, which is the old default behavior. - -test_boost Whether or not to test the ability of RCU to do priority - boosting. Defaults to "test_boost=1", which performs - RCU priority-inversion testing only if the selected - RCU implementation supports priority boosting. Specifying - "test_boost=0" never performs RCU priority-inversion - testing. Specifying "test_boost=2" performs RCU - priority-inversion testing even if the selected RCU - implementation does not support RCU priority boosting, - which can be used to test rcutorture's ability to - carry out RCU priority-inversion testing. - -test_boost_interval - The number of seconds in an RCU priority-inversion test - cycle. Defaults to "test_boost_interval=7". It is - usually wise for this value to be relatively prime to - the value selected for "stutter". - -test_boost_duration - The number of seconds to do RCU priority-inversion testing - within any given "test_boost_interval". Defaults to - "test_boost_duration=4". - -test_no_idle_hz Whether or not to test the ability of RCU to operate in - a kernel that disables the scheduling-clock interrupt to - idle CPUs. Boolean parameter, "1" to test, "0" otherwise. - Defaults to omitting this test. - -torture_type The type of RCU to test, with string values as follows: - - "rcu": rcu_read_lock(), rcu_read_unlock() and call_rcu(), - along with expedited, synchronous, and polling - variants. - - "rcu_bh": rcu_read_lock_bh(), rcu_read_unlock_bh(), and - call_rcu_bh(), along with expedited and synchronous - variants. - - "rcu_busted": This tests an intentionally incorrect version - of RCU in order to help test rcutorture itself. - - "srcu": srcu_read_lock(), srcu_read_unlock() and - call_srcu(), along with expedited and - synchronous variants. - - "sched": preempt_disable(), preempt_enable(), and - call_rcu_sched(), along with expedited, - synchronous, and polling variants. - - "tasks": voluntary context switch and call_rcu_tasks(), - along with expedited and synchronous variants. - - Defaults to "rcu". - -verbose Enable debug printk()s. Default is disabled. - +Module parameters are prefixed by "rcutorture." in +Documentation/admin-guide/kernel-parameters.txt. OUTPUT diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt index 4a6854318b17..1ace20815bb1 100644 --- a/Documentation/RCU/whatisRCU.txt +++ b/Documentation/RCU/whatisRCU.txt @@ -302,7 +302,7 @@ rcu_dereference() must prohibit. The rcu_dereference_protected() variant takes a lockdep expression to indicate which locks must be acquired by the caller. If the indicated protection is not provided, - a lockdep splat is emitted. See RCU/Design/Requirements.html + a lockdep splat is emitted. See RCU/Design/Requirements/Requirements.html and the API's code comments for more details and example usage. The following diagram shows how each API communicates among the @@ -560,7 +560,7 @@ presents two such "toy" implementations of RCU, one that is implemented in terms of familiar locking primitives, and another that more closely resembles "classic" RCU. Both are way too simple for real-world use, lacking both functionality and performance. However, they are useful -in getting a feel for how RCU works. See kernel/rcupdate.c for a +in getting a feel for how RCU works. See kernel/rcu/update.c for a production-quality implementation, and see: http://www.rdrop.com/users/paulmck/RCU diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index b0dbb2fa401f..bec49d593583 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3654,19 +3654,6 @@ latencies, which will choose a value aligned with the appropriate hardware boundaries. - rcutree.jiffies_till_sched_qs= [KNL] - Set required age in jiffies for a - given grace period before RCU starts - soliciting quiescent-state help from - rcu_note_context_switch(). If not specified, the - kernel will calculate a value based on the most - recent settings of rcutree.jiffies_till_first_fqs - and rcutree.jiffies_till_next_fqs. - This calculated value may be viewed in - rcutree.jiffies_to_sched_qs. Any attempt to - set rcutree.jiffies_to_sched_qs will be - cheerfully overwritten. - rcutree.jiffies_till_first_fqs= [KNL] Set delay from grace-period initialization to first attempt to force quiescent states. @@ -3678,6 +3665,20 @@ quiescent states. Units are jiffies, minimum value is one, and maximum value is HZ. + rcutree.jiffies_till_sched_qs= [KNL] + Set required age in jiffies for a + given grace period before RCU starts + soliciting quiescent-state help from + rcu_note_context_switch() and cond_resched(). + If not specified, the kernel will calculate + a value based on the most recent settings + of rcutree.jiffies_till_first_fqs + and rcutree.jiffies_till_next_fqs. + This calculated value may be viewed in + rcutree.jiffies_to_sched_qs. Any attempt to set + rcutree.jiffies_to_sched_qs will be cheerfully + overwritten. + rcutree.kthread_prio= [KNL,BOOT] Set the SCHED_FIFO priority of the RCU per-CPU kthreads (rcuc/N). This value is also used for diff --git a/MAINTAINERS b/MAINTAINERS index 4d04cebb4a71..e2e4eac8a7a7 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10791,6 +10791,12 @@ F: drivers/power/supply/bq27xxx_battery_i2c.c F: drivers/power/supply/isp1704_charger.c F: drivers/power/supply/rx51_battery.c +NOLIBC HEADER FILE +M: Willy Tarreau <w@1wt.eu> +S: Maintained +T: git git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/nolibc.git +F: tools/include/nolibc/ + NTB AMD DRIVER M: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> L: linux-ntb@googlegroups.com diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index 20561a60db9c..0e9bd9c83870 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -211,9 +211,6 @@ void __warn(const char *file, int line, void *caller, unsigned taint, /* * WARN_ON_SMP() is for cases that the warning is either * meaningless for !SMP or may even cause failures. - * This is usually used for cases that we have - * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked() - * returns 0 for uniprocessor settings. * It can also be used with values that are only defined * on SMP: * diff --git a/include/linux/rcu_node_tree.h b/include/linux/rcu_node_tree.h index 426cee67f0e2..b8e094b125ee 100644 --- a/include/linux/rcu_node_tree.h +++ b/include/linux/rcu_node_tree.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * RCU node combining tree definitions. These are used to compute * global attributes while avoiding common-case global contention. A key @@ -11,23 +12,9 @@ * because the size of the TREE SRCU srcu_struct structure depends * on these definitions. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2017 * - * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com> + * Author: Paul E. McKenney <paulmck@linux.ibm.com> */ #ifndef __LINUX_RCU_NODE_TREE_H diff --git a/include/linux/rcu_segcblist.h b/include/linux/rcu_segcblist.h index c3ad00e63556..87404cb015f1 100644 --- a/include/linux/rcu_segcblist.h +++ b/include/linux/rcu_segcblist.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * RCU segmented callback lists * @@ -5,23 +6,9 @@ * because the size of the TREE SRCU srcu_struct structure depends * on these definitions. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2017 * - * Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com> + * Authors: Paul E. McKenney <paulmck@linux.net.ibm.com> */ #ifndef __INCLUDE_LINUX_RCU_SEGCBLIST_H diff --git a/include/linux/rcu_sync.h b/include/linux/rcu_sync.h index ece7ed9a4a70..6fc53a1345b3 100644 --- a/include/linux/rcu_sync.h +++ b/include/linux/rcu_sync.h @@ -1,20 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * RCU-based infrastructure for lightweight reader-writer locking * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (c) 2015, Red Hat, Inc. * * Author: Oleg Nesterov <oleg@redhat.com> diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 0e39e0d2629e..6cdb1db776cf 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -1,25 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update mechanism for mutual exclusion * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2001 * * Author: Dipankar Sarma <dipankar@in.ibm.com> * - * Based on the original work by Paul McKenney <paulmck@us.ibm.com> + * Based on the original work by Paul McKenney <paulmck@vnet.ibm.com> * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. * Papers: * http://www.rdrop.com/users/paulmck/paper/rclockpdcsproof.pdf @@ -89,7 +76,7 @@ static inline int rcu_preempt_depth(void) /* Internal to kernel */ void rcu_init(void); extern int rcu_scheduler_active __read_mostly; -void rcu_check_callbacks(int user); +void rcu_sched_clock_irq(int user); void rcu_report_dead(unsigned int cpu); void rcutree_migrate_callbacks(int cpu); @@ -309,16 +296,16 @@ static inline void rcu_preempt_sleep_check(void) { } */ #ifdef __CHECKER__ -#define rcu_dereference_sparse(p, space) \ +#define rcu_check_sparse(p, space) \ ((void)(((typeof(*p) space *)p) == p)) #else /* #ifdef __CHECKER__ */ -#define rcu_dereference_sparse(p, space) +#define rcu_check_sparse(p, space) #endif /* #else #ifdef __CHECKER__ */ #define __rcu_access_pointer(p, space) \ ({ \ typeof(*p) *_________p1 = (typeof(*p) *__force)READ_ONCE(p); \ - rcu_dereference_sparse(p, space); \ + rcu_check_sparse(p, space); \ ((typeof(*p) __force __kernel *)(_________p1)); \ }) #define __rcu_dereference_check(p, c, space) \ @@ -326,13 +313,13 @@ static inline void rcu_preempt_sleep_check(void) { } /* Dependency order vs. p above. */ \ typeof(*p) *________p1 = (typeof(*p) *__force)READ_ONCE(p); \ RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_check() usage"); \ - rcu_dereference_sparse(p, space); \ + rcu_check_sparse(p, space); \ ((typeof(*p) __force __kernel *)(________p1)); \ }) #define __rcu_dereference_protected(p, c, space) \ ({ \ RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_protected() usage"); \ - rcu_dereference_sparse(p, space); \ + rcu_check_sparse(p, space); \ ((typeof(*p) __force __kernel *)(p)); \ }) #define rcu_dereference_raw(p) \ @@ -382,6 +369,7 @@ static inline void rcu_preempt_sleep_check(void) { } #define rcu_assign_pointer(p, v) \ ({ \ uintptr_t _r_a_p__v = (uintptr_t)(v); \ + rcu_check_sparse(p, __rcu); \ \ if (__builtin_constant_p(v) && (_r_a_p__v) == (uintptr_t)NULL) \ WRITE_ONCE((p), (typeof(p))(_r_a_p__v)); \ @@ -785,7 +773,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) */ #define RCU_INIT_POINTER(p, v) \ do { \ - rcu_dereference_sparse(p, __rcu); \ + rcu_check_sparse(p, __rcu); \ WRITE_ONCE(p, RCU_INITIALIZER(v)); \ } while (0) @@ -859,7 +847,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) /* Has the specified rcu_head structure been handed to call_rcu()? */ -/* +/** * rcu_head_init - Initialize rcu_head for rcu_head_after_call_rcu() * @rhp: The rcu_head structure to initialize. * @@ -874,10 +862,10 @@ static inline void rcu_head_init(struct rcu_head *rhp) rhp->func = (rcu_callback_t)~0L; } -/* +/** * rcu_head_after_call_rcu - Has this rcu_head been passed to call_rcu()? * @rhp: The rcu_head structure to test. - * @func: The function passed to call_rcu() along with @rhp. + * @f: The function passed to call_rcu() along with @rhp. * * Returns @true if the @rhp has been passed to call_rcu() with @func, * and @false otherwise. Emits a warning in any other case, including diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index af65d1f36ddb..8e727f57d814 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -1,23 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2008 * - * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com> + * Author: Paul E. McKenney <paulmck@linux.ibm.com> * * For detailed explanation of Read-Copy Update mechanism see - * Documentation/RCU diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 7f83179177d1..735601ac27d3 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -1,26 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update mechanism for mutual exclusion (tree-based version) * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2008 * * Author: Dipankar Sarma <dipankar@in.ibm.com> - * Paul E. McKenney <paulmck@linux.vnet.ibm.com> Hierarchical algorithm + * Paul E. McKenney <paulmck@linux.ibm.com> Hierarchical algorithm * - * Based on the original work by Paul McKenney <paulmck@us.ibm.com> + * Based on the original work by Paul McKenney <paulmck@linux.ibm.com> * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. * * For detailed explanation of Read-Copy Update mechanism see - diff --git a/include/linux/srcu.h b/include/linux/srcu.h index 33cf83b9bda8..c495b2d51569 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -1,24 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Sleepable Read-Copy Update mechanism for mutual exclusion * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2006 * Copyright (C) Fujitsu, 2012 * - * Author: Paul McKenney <paulmck@us.ibm.com> + * Author: Paul McKenney <paulmck@linux.ibm.com> * Lai Jiangshan <laijs@cn.fujitsu.com> * * For detailed explanation of Read-Copy Update mechanism see - diff --git a/include/linux/srcutiny.h b/include/linux/srcutiny.h index b19216aaaef2..5a5a1941ca15 100644 --- a/include/linux/srcutiny.h +++ b/include/linux/srcutiny.h @@ -1,24 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Sleepable Read-Copy Update mechanism for mutual exclusion, * tiny variant. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2017 * - * Author: Paul McKenney <paulmck@us.ibm.com> + * Author: Paul McKenney <paulmck@linux.ibm.com> */ #ifndef _LINUX_SRCU_TINY_H diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index 0faa978c9880..7f7c8c050f63 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -1,24 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Sleepable Read-Copy Update mechanism for mutual exclusion, * tree variant. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2017 * - * Author: Paul McKenney <paulmck@us.ibm.com> + * Author: Paul McKenney <paulmck@linux.ibm.com> */ #ifndef _LINUX_SRCU_TREE_H diff --git a/include/linux/torture.h b/include/linux/torture.h index 48fad21109fc..23d80db426d7 100644 --- a/include/linux/torture.h +++ b/include/linux/torture.h @@ -1,23 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Common functions for in-kernel torture tests. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2014 * - * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com> + * Author: Paul E. McKenney <paulmck@linux.ibm.com> */ #ifndef __LINUX_TORTURE_H @@ -50,11 +37,12 @@ do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! %s\n", torture_type, s); } while (0) /* Definitions for online/offline exerciser. */ +typedef void torture_ofl_func(void); bool torture_offline(int cpu, long *n_onl_attempts, long *n_onl_successes, unsigned long *sum_offl, int *min_onl, int *max_onl); bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes, unsigned long *sum_onl, int *min_onl, int *max_onl); -int torture_onoff_init(long ooholdoff, long oointerval); +int torture_onoff_init(long ooholdoff, long oointerval, torture_ofl_func *f); void torture_onoff_stats(void); bool torture_onoff_failures(void); diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index 7d0b0ed74404..ad40a2617063 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -1,23 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Module-based torture test facility for locking * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2014 * - * Authors: Paul E. McKenney <paulmck@us.ibm.com> + * Authors: Paul E. McKenney <paulmck@linux.ibm.com> * Davidlohr Bueso <dave@stgolabs.net> * Based on kernel/rcu/torture.c. */ @@ -45,7 +32,7 @@ #include <linux/torture.h> MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>"); +MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>"); torture_param(int, nwriters_stress, -1, "Number of write-locking stress-test threads"); @@ -970,7 +957,7 @@ static int __init lock_torture_init(void) /* Prepare torture context. */ if (onoff_interval > 0) { firsterr = torture_onoff_init(onoff_holdoff * HZ, - onoff_interval * HZ); + onoff_interval * HZ, NULL); if (firsterr) goto unwind; } diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index 75787186bd4f..acee72c0b24b 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -1,23 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update definitions shared among RCU implementations. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2011 * - * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com> + * Author: Paul E. McKenney <paulmck@linux.ibm.com> */ #ifndef __LINUX_RCU_H @@ -30,7 +17,7 @@ #define RCU_TRACE(stmt) #endif /* #else #ifdef CONFIG_RCU_TRACE */ -/* Offset to allow for unmatched rcu_irq_{enter,exit}(). */ +/* Offset to allow distinguishing irq vs. task-based idle entry/exit. */ #define DYNTICK_IRQ_NONIDLE ((LONG_MAX / 2) + 1) diff --git a/kernel/rcu/rcu_segcblist.c b/kernel/rcu/rcu_segcblist.c index 5aff271adf1e..9bd5f6023c21 100644 --- a/kernel/rcu/rcu_segcblist.c +++ b/kernel/rcu/rcu_segcblist.c @@ -1,23 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * RCU segmented callback lists, function definitions * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2017 * - * Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com> + * Authors: Paul E. McKenney <paulmck@linux.ibm.com> */ #include <linux/types.h> diff --git a/kernel/rcu/rcu_segcblist.h b/kernel/rcu/rcu_segcblist.h index 948470cef385..71b64648464e 100644 --- a/kernel/rcu/rcu_segcblist.h +++ b/kernel/rcu/rcu_segcblist.h @@ -1,23 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * RCU segmented callback lists, internal-to-rcu header file * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2017 * - * Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com> + * Authors: Paul E. McKenney <paulmck@linux.ibm.com> */ #include <linux/rcu_segcblist.h> diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c index b459da70b4fc..c29761152874 100644 --- a/kernel/rcu/rcuperf.c +++ b/kernel/rcu/rcuperf.c @@ -1,23 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Read-Copy Update module-based performance-test facility * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2015 * - * Authors: Paul E. McKenney <paulmck@us.ibm.com> + * Authors: Paul E. McKenney <paulmck@linux.ibm.com> */ #define pr_fmt(fmt) fmt @@ -54,7 +41,7 @@ #include "rcu.h" MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.vnet.ibm.com>"); +MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>"); #define PERF_FLAG "-perf:" #define PERFOUT_STRING(s) \ @@ -83,13 +70,19 @@ MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.vnet.ibm.com>"); * Various other use cases may of course be specified. */ +#ifdef MODULE +# define RCUPERF_SHUTDOWN 0 +#else +# define RCUPERF_SHUTDOWN 1 +#endif + torture_param(bool, gp_async, false, "Use asynchronous GP wait primitives"); torture_param(int, gp_async_max, 1000, "Max # outstanding waits per reader"); torture_param(bool, gp_exp, false, "Use expedited GP wait primitives"); torture_param(int, holdoff, 10, "Holdoff time before test start (s)"); torture_param(int, nreaders, -1, "Number of RCU reader threads"); torture_param(int, nwriters, -1, "Number of RCU updater threads"); -torture_param(bool, shutdown, !IS_ENABLED(MODULE), +torture_param(bool, shutdown, RCUPERF_SHUTDOWN, "Shutdown at end of performance tests."); torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable"); diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index f6e85faa4ff4..f14d1b18a74f 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1,23 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Read-Copy Update module-based torture test facility * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2005, 2006 * - * Authors: Paul E. McKenney <paulmck@us.ibm.com> + * Authors: Paul E. McKenney <paulmck@linux.ibm.com> * Josh Triplett <josh@joshtriplett.org> * * See also: Documentation/RCU/torture.txt @@ -61,7 +48,7 @@ #include "rcu.h" MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@joshtriplett.org>"); +MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com> and Josh Triplett <josh@joshtriplett.org>"); /* Bits for ->extendables field, extendables param, and related definitions. */ @@ -1630,21 +1617,34 @@ static bool rcu_fwd_emergency_stop; #define MIN_FWD_CB_LAUNDERS 3 /* This many CB invocations to count. */ #define MIN_FWD_CBS_LAUNDERED 100 /* Number of counted CBs. */ #define FWD_CBS_HIST_DIV 10 /* Histogram buckets/second. */ -static long n_launders_hist[2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV)]; +struct rcu_launder_hist { + long n_launders; + unsigned long launder_gp_seq; +}; +#define N_LAUNDERS_HIST (2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV)) +static struct rcu_launder_hist n_launders_hist[N_LAUNDERS_HIST]; +static unsigned long rcu_launder_gp_seq_start; static void rcu_torture_fwd_cb_hist(void) { + unsigned long gps; + unsigned long gps_old; int i; int j; for (i = ARRAY_SIZE(n_launders_hist) - 1; i > 0; i--) - if (n_launders_hist[i] > 0) + if (n_launders_hist[i].n_launders > 0) break; pr_alert("%s: Callback-invocation histogram (duration %lu jiffies):", __func__, jiffies - rcu_fwd_startat); - for (j = 0; j <= i; j++) - pr_cont(" %ds/%d: %ld", - j + 1, FWD_CBS_HIST_DIV, n_launders_hist[j]); + gps_old = rcu_launder_gp_seq_start; + for (j = 0; j <= i; j++) { + gps = n_launders_hist[j].launder_gp_seq; + pr_cont(" %ds/%d: %ld:%ld", + j + 1, FWD_CBS_HIST_DIV, n_launders_hist[j].n_launders, + rcutorture_seq_diff(gps, gps_old)); + gps_old = gps; + } pr_cont("\n"); } @@ -1666,7 +1666,8 @@ static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp) i = ((jiffies - rcu_fwd_startat) / (HZ / FWD_CBS_HIST_DIV)); if (i >= ARRAY_SIZE(n_launders_hist)) i = ARRAY_SIZE(n_launders_hist) - 1; - n_launders_hist[i]++; + n_launders_hist[i].n_launders++; + n_launders_hist[i].launder_gp_seq = cur_ops->get_gp_seq(); spin_unlock_irqrestore(&rcu_fwd_lock, flags); } @@ -1786,9 +1787,10 @@ static void rcu_torture_fwd_prog_cr(void) n_max_cbs = 0; n_max_gps = 0; for (i = 0; i < ARRAY_SIZE(n_launders_hist); i++) - n_launders_hist[i] = 0; + n_launders_hist[i].n_launders = 0; cver = READ_ONCE(rcu_torture_current_version); gps = cur_ops->get_gp_seq(); + rcu_launder_gp_seq_start = gps; while (time_before(jiffies, stopat) && !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { rfcp = READ_ONCE(rcu_fwd_cb_head); @@ -2228,6 +2230,14 @@ static void rcu_test_debug_objects(void) #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ } +static void rcutorture_sync(void) +{ + static unsigned long n; + + if (cur_ops->sync && !(++n & 0xfff)) + cur_ops->sync(); +} + static int __init rcu_torture_init(void) { @@ -2389,7 +2399,8 @@ rcu_torture_init(void) firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup); if (firsterr) goto unwind; - firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval); + firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval, + rcutorture_sync); if (firsterr) goto unwind; firsterr = rcu_torture_stall_init(); diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c index 32dfd6522548..5d4a39a6505a 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -1,24 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Sleepable Read-Copy Update mechanism for mutual exclusion, * tiny version for non-preemptible single-CPU use. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2017 * - * Author: Paul McKenney <paulmck@us.ibm.com> + * Author: Paul McKenney <paulmck@linux.ibm.com> */ #include <linux/export.h> diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 7f041f2435df..a60b8ba9e1ac 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -1,24 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Sleepable Read-Copy Update mechanism for mutual exclusion. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2006 * Copyright (C) Fujitsu, 2012 * - * Author: Paul McKenney <paulmck@us.ibm.com> + * Author: Paul McKenney <paulmck@linux.ibm.com> * Lai Jiangshan <laijs@cn.fujitsu.com> * * For detailed explanation of Read-Copy Update mechanism see - diff --git a/kernel/rcu/sync.c b/kernel/rcu/sync.c index be10036fa621..a8304d90573f 100644 --- a/kernel/rcu/sync.c +++ b/kernel/rcu/sync.c @@ -1,20 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * RCU-based infrastructure for lightweight reader-writer locking * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (c) 2015, Red Hat, Inc. * * Author: Oleg Nesterov <oleg@redhat.com> diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c index 5f5963ba313e..911bd9076d43 100644 --- a/kernel/rcu/tiny.c +++ b/kernel/rcu/tiny.c @@ -1,23 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2008 * - * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com> + * Author: Paul E. McKenney <paulmck@linux.ibm.com> * * For detailed explanation of Read-Copy Update mechanism see - * Documentation/RCU @@ -76,7 +63,7 @@ void rcu_qs(void) * be called from hardirq context. It is normally called from the * scheduling-clock interrupt. */ -void rcu_check_callbacks(int user) +void rcu_sched_clock_irq(int user) { if (user) { rcu_qs(); diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 127255795859..3b084dbfb4bc 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1,27 +1,14 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Read-Copy Update mechanism for mutual exclusion * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2008 * * Authors: Dipankar Sarma <dipankar@in.ibm.com> * Manfred Spraul <manfred@colorfullife.com> - * Paul E. McKenney <paulmck@linux.vnet.ibm.com> Hierarchical version + * Paul E. McKenney <paulmck@linux.ibm.com> Hierarchical version * - * Based on the original work by Paul McKenney <paulmck@us.ibm.com> + * Based on the original work by Paul McKenney <paulmck@linux.ibm.com> * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. * * For detailed explanation of Read-Copy Update mechanism see - @@ -725,7 +712,6 @@ static __always_inline void rcu_nmi_exit_common(bool irq) /** * rcu_nmi_exit - inform RCU of exit from NMI context - * @irq: Is this call from rcu_irq_exit? * * If you add or remove a call to rcu_nmi_exit(), be sure to test * with CONFIG_RCU_EQS_DEBUG=y. @@ -1139,7 +1125,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) } /* - * NO_HZ_FULL CPUs can run in-kernel without rcu_check_callbacks! + * NO_HZ_FULL CPUs can run in-kernel without rcu_sched_clock_irq! * The above code handles this, but only for straight cond_resched(). * And some in-kernel loops check need_resched() before calling * cond_resched(), which defeats the above code for CPUs that are @@ -2532,14 +2518,14 @@ static void rcu_do_batch(struct rcu_data *rdp) } /* - * Check to see if this CPU is in a non-context-switch quiescent state - * (user mode or idle loop for rcu, non-softirq execution for rcu_bh). - * Also schedule RCU core processing. - * - * This function must be called from hardirq context. It is normally - * invoked from the scheduling-clock interrupt. + * This function is invoked from each scheduling-clock interrupt, + * and checks to see if this CPU is in a non-context-switch quiescent + * state, for example, user mode or idle loop. It also schedules RCU + * core processing. If the current grace period has gone on too long, + * it will ask the scheduler to manufacture a context switch for the sole + * purpose of providing a providing the needed quiescent state. */ -void rcu_check_callbacks(int user) +void rcu_sched_clock_irq(int user) { trace_rcu_utilization(TPS("Start scheduler-tick")); raw_cpu_inc(rcu_data.ticks_this_gp); @@ -2552,7 +2538,7 @@ void rcu_check_callbacks(int user) } __this_cpu_write(rcu_data.rcu_urgent_qs, false); } - rcu_flavor_check_callbacks(user); + rcu_flavor_sched_clock_irq(user); if (rcu_pending()) invoke_rcu_core(); @@ -2742,12 +2728,8 @@ void rcu_fwd_progress_check(unsigned long j) } EXPORT_SYMBOL_GPL(rcu_fwd_progress_check); -/* - * This does the RCU core processing work for the specified rcu_data - * structures. This may be called only from the CPU to whom the rdp - * belongs. - */ -static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused) +/* Perform RCU core processing work for the current CPU. */ +static __latent_entropy void rcu_core(struct softirq_action *unused) { unsigned long flags; struct rcu_data *rdp = raw_cpu_ptr(&rcu_data); @@ -3852,7 +3834,7 @@ void __init rcu_init(void) rcu_init_one(); if (dump_tree) rcu_dump_rcu_node_tree(); - open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); + open_softirq(RCU_SOFTIRQ, rcu_core); /* * We don't need protection against CPU-hotplug here because diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 4bba017c703c..bb4f995f2d3f 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -1,25 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update mechanism for mutual exclusion (tree-based version) * Internal non-public definitions. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2008 * * Author: Ingo Molnar <mingo@elte.hu> - * Paul E. McKenney <paulmck@linux.vnet.ibm.com> + * Paul E. McKenney <paulmck@linux.ibm.com> */ #include <linux/cache.h> @@ -417,7 +404,7 @@ static void rcu_print_detail_task_stall(void); static int rcu_print_task_stall(struct rcu_node *rnp); static int rcu_print_task_exp_stall(struct rcu_node *rnp); static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp); -static void rcu_flavor_check_callbacks(int user); +static void rcu_flavor_sched_clock_irq(int user); void call_rcu(struct rcu_head *head, rcu_callback_t func); static void dump_blkd_tasks(struct rcu_node *rnp, int ncheck); static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags); diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index d882ca0cd01b..4c2a0189e748 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -1,23 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * RCU expedited grace periods * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2016 * - * Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com> + * Authors: Paul E. McKenney <paulmck@linux.ibm.com> */ #include <linux/lockdep.h> @@ -448,7 +435,6 @@ static void sync_rcu_exp_select_cpus(void) continue; } INIT_WORK(&rnp->rew.rew_work, sync_rcu_exp_select_node_cpus); - preempt_disable(); cpu = find_next_bit(&rnp->ffmask, BITS_PER_LONG, -1); /* If all offline, queue the work on an unbound CPU. */ if (unlikely(cpu > rnp->grphi - rnp->grplo)) @@ -456,7 +442,6 @@ static void sync_rcu_exp_select_cpus(void) else cpu += rnp->grplo; queue_work_on(cpu, rcu_par_gp_wq, &rnp->rew.rew_work); - preempt_enable(); rnp->exp_need_flush = true; } diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 8ceed9e25ad5..97dba50f6fb2 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1,27 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update mechanism for mutual exclusion (tree-based version) * Internal non-public definitions that provide either classic * or preemptible semantics. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright Red Hat, 2009 * Copyright IBM Corporation, 2009 * * Author: Ingo Molnar <mingo@elte.hu> - * Paul E. McKenney <paulmck@linux.vnet.ibm.com> + * Paul E. McKenney <paulmck@linux.ibm.com> */ #include <linux/delay.h> @@ -297,7 +284,7 @@ static void rcu_qs(void) __this_cpu_read(rcu_data.gp_seq), TPS("cpuqs")); __this_cpu_write(rcu_data.cpu_no_qs.b.norm, false); - barrier(); /* Coordinate with rcu_flavor_check_callbacks(). */ + barrier(); /* Coordinate with rcu_flavor_sched_clock_irq(). */ current->rcu_read_unlock_special.b.need_qs = false; } } @@ -778,13 +765,13 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) } /* - * Check for a quiescent state from the current CPU. When a task blocks, - * the task is recorded in the corresponding CPU's rcu_node structure, - * which is checked elsewhere. - * - * Caller must disable hard irqs. + * Check for a quiescent state from the current CPU, including voluntary + * context switches for Tasks RCU. When a task blocks, the task is + * recorded in the corresponding CPU's rcu_node structure, which is checked + * elsewhere, hence this function need only check for quiescent states + * related to the current CPU, not to those related to tasks. */ -static void rcu_flavor_check_callbacks(int user) +static void rcu_flavor_sched_clock_irq(int user) { struct task_struct *t = current; @@ -1030,14 +1017,10 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) } /* - * Check to see if this CPU is in a non-context-switch quiescent state - * (user mode or idle loop for rcu, non-softirq execution for rcu_bh). - * Also schedule RCU core processing. - * - * This function must be called from hardirq context. It is normally - * invoked from the scheduling-clock interrupt. + * Check to see if this CPU is in a non-context-switch quiescent state, + * namely user mode and idle loop. */ -static void rcu_flavor_check_callbacks(int user) +static void rcu_flavor_sched_clock_irq(int user) { if (user || rcu_is_cpu_rrupt_from_idle()) { diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 1971869c4072..e3c6395c9b4c 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -1,26 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Read-Copy Update mechanism for mutual exclusion * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2001 * * Authors: Dipankar Sarma <dipankar@in.ibm.com> * Manfred Spraul <manfred@colorfullife.com> * - * Based on the original work by Paul McKenney <paulmck@us.ibm.com> + * Based on the original work by Paul McKenney <paulmck@linux.ibm.com> * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. * Papers: * http://www.rdrop.com/users/paulmck/paper/rclockpdcsproof.pdf diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 444156debfa0..6eb7cc4b6d52 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1632,7 +1632,7 @@ void update_process_times(int user_tick) /* Note: this timer irq context must be accounted for as well. */ account_process_tick(p, user_tick); run_local_timers(); - rcu_check_callbacks(user_tick); + rcu_sched_clock_irq(user_tick); #ifdef CONFIG_IRQ_WORK if (in_irq()) irq_work_tick(); diff --git a/kernel/torture.c b/kernel/torture.c index bbf6d473e50c..8faa1a9aaeb9 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -1,23 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Common functions for in-kernel torture tests. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2014 * - * Author: Paul E. McKenney <paulmck@us.ibm.com> + * Author: Paul E. McKenney <paulmck@linux.ibm.com> * Based on kernel/rcu/torture.c. */ @@ -53,7 +40,7 @@ #include "rcu/rcu.h" MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>"); +MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>"); static char *torture_type; static int verbose; @@ -75,6 +62,7 @@ static DEFINE_MUTEX(fullstop_mutex); static struct task_struct *onoff_task; static long onoff_holdoff; static long onoff_interval; +static torture_ofl_func *onoff_f; static long n_offline_attempts; static long n_offline_successes; static unsigned long sum_offline; @@ -118,6 +106,8 @@ bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes, pr_alert("%s" TORTURE_FLAG "torture_onoff task: offlined %d\n", torture_type, cpu); + if (onoff_f) + onoff_f(); (*n_offl_successes)++; delta = jiffies - starttime; *sum_offl += delta; @@ -243,11 +233,12 @@ stop: /* * Initiate online-offline handling. */ -int torture_onoff_init(long ooholdoff, long oointerval) +int torture_onoff_init(long ooholdoff, long oointerval, torture_ofl_func *f) { #ifdef CONFIG_HOTPLUG_CPU onoff_holdoff = ooholdoff; onoff_interval = oointerval; + onoff_f = f; if (onoff_interval <= 0) return 0; return torture_create_kthread(torture_onoff, NULL, onoff_task); diff --git a/tools/testing/selftests/rcutorture/bin/nolibc.h b/tools/include/nolibc/nolibc.h index f98f5b92d3eb..1708e9f9f8aa 100644 --- a/tools/testing/selftests/rcutorture/bin/nolibc.h +++ b/tools/include/nolibc/nolibc.h @@ -3,7 +3,85 @@ * Copyright (C) 2017-2018 Willy Tarreau <w@1wt.eu> */ -/* some archs (at least aarch64) don't expose the regular syscalls anymore by +/* + * This file is designed to be used as a libc alternative for minimal programs + * with very limited requirements. It consists of a small number of syscall and + * type definitions, and the minimal startup code needed to call main(). + * All syscalls are declared as static functions so that they can be optimized + * away by the compiler when not used. + * + * Syscalls are split into 3 levels: + * - The lower level is the arch-specific syscall() definition, consisting in + * assembly code in compound expressions. These are called my_syscall0() to + * my_syscall6() depending on the number of arguments. The MIPS + * implementation is limited to 5 arguments. All input arguments are cast + * to a long stored in a register. These expressions always return the + * syscall's return value as a signed long value which is often either a + * pointer or the negated errno value. + * + * - The second level is mostly architecture-independent. It is made of + * static functions called sys_<name>() which rely on my_syscallN() + * depending on the syscall definition. These functions are responsible + * for exposing the appropriate types for the syscall arguments (int, + * pointers, etc) and for setting the appropriate return type (often int). + * A few of them are architecture-specific because the syscalls are not all + * mapped exactly the same among architectures. For example, some archs do + * not implement select() and need pselect6() instead, so the sys_select() + * function will have to abstract this. + * + * - The third level is the libc call definition. It exposes the lower raw + * sys_<name>() calls in a way that looks like what a libc usually does, + * takes care of specific input values, and of setting errno upon error. + * There can be minor variations compared to standard libc calls. For + * example the open() call always takes 3 args here. + * + * The errno variable is declared static and unused. This way it can be + * optimized away if not used. However this means that a program made of + * multiple C files may observe different errno values (one per C file). For + * the type of programs this project targets it usually is not a problem. The + * resulting program may even be reduced by defining the NOLIBC_IGNORE_ERRNO + * macro, in which case the errno value will never be assigned. + * + * Some stdint-like integer types are defined. These are valid on all currently + * supported architectures, because signs are enforced, ints are assumed to be + * 32 bits, longs the size of a pointer and long long 64 bits. If more + * architectures have to be supported, this may need to be adapted. + * + * Some macro definitions like the O_* values passed to open(), and some + * structures like the sys_stat struct depend on the architecture. + * + * The definitions start with the architecture-specific parts, which are picked + * based on what the compiler knows about the target architecture, and are + * completed with the generic code. Since it is the compiler which sets the + * target architecture, cross-compiling normally works out of the box without + * having to specify anything. + * + * Finally some very common libc-level functions are provided. It is the case + * for a few functions usually found in string.h, ctype.h, or stdlib.h. Nothing + * is currently provided regarding stdio emulation. + * + * The macro NOLIBC is always defined, so that it is possible for a program to + * check this macro to know if it is being built against and decide to disable + * some features or simply not to include some standard libc files. + * + * Ideally this file should be split in multiple files for easier long term + * maintenance, but provided as a single file as it is now, it's quite + * convenient to use. Maybe some variations involving a set of includes at the + * top could work. + * + * A simple static executable may be built this way : + * $ gcc -fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib \ + * -static -include nolibc.h -lgcc -o hello hello.c + * + * A very useful calling convention table may be found here : + * http://man7.org/linux/man-pages/man2/syscall.2.html + * + * This doc is quite convenient though not necessarily up to date : + * https://w3challs.com/syscalls/ + * + */ + +/* Some archs (at least aarch64) don't expose the regular syscalls anymore by * default, either because they have an "_at" replacement, or because there are * more modern alternatives. For now we'd rather still use them. */ @@ -19,18 +97,6 @@ #define NOLIBC -/* Build a static executable this way : - * $ gcc -fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib \ - * -static -include nolibc.h -lgcc -o hello hello.c - * - * Useful calling convention table found here : - * http://man7.org/linux/man-pages/man2/syscall.2.html - * - * This doc is even better : - * https://w3challs.com/syscalls/ - */ - - /* this way it will be removed if unused */ static int errno; @@ -81,9 +147,9 @@ typedef signed long time_t; /* for poll() */ struct pollfd { - int fd; - short int events; - short int revents; + int fd; + short int events; + short int revents; }; /* for select() */ @@ -239,7 +305,7 @@ struct stat { "syscall\n" \ : "=a" (_ret) \ : "0"(_num) \ - : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -255,7 +321,7 @@ struct stat { : "=a" (_ret) \ : "r"(_arg1), \ "0"(_num) \ - : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -272,7 +338,7 @@ struct stat { : "=a" (_ret) \ : "r"(_arg1), "r"(_arg2), \ "0"(_num) \ - : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -290,7 +356,7 @@ struct stat { : "=a" (_ret) \ : "r"(_arg1), "r"(_arg2), "r"(_arg3), \ "0"(_num) \ - : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -1006,7 +1072,7 @@ struct sys_stat_struct { : "=r"(_num), "=r"(_arg4) \ : "r"(_num) \ : "memory", "cc", "at", "v1", "hi", "lo", \ - \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ ); \ _arg4 ? -_num : _num; \ }) @@ -1025,7 +1091,7 @@ struct sys_stat_struct { : "0"(_num), \ "r"(_arg1) \ : "memory", "cc", "at", "v1", "hi", "lo", \ - \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ ); \ _arg4 ? -_num : _num; \ }) @@ -1045,7 +1111,7 @@ struct sys_stat_struct { : "0"(_num), \ "r"(_arg1), "r"(_arg2) \ : "memory", "cc", "at", "v1", "hi", "lo", \ - \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ ); \ _arg4 ? -_num : _num; \ }) @@ -1066,7 +1132,7 @@ struct sys_stat_struct { : "0"(_num), \ "r"(_arg1), "r"(_arg2), "r"(_arg3) \ : "memory", "cc", "at", "v1", "hi", "lo", \ - \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ ); \ _arg4 ? -_num : _num; \ }) @@ -1087,7 +1153,7 @@ struct sys_stat_struct { : "0"(_num), \ "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4) \ : "memory", "cc", "at", "v1", "hi", "lo", \ - \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ ); \ _arg4 ? -_num : _num; \ }) @@ -1110,7 +1176,7 @@ struct sys_stat_struct { : "0"(_num), \ "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5) \ : "memory", "cc", "at", "v1", "hi", "lo", \ - \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ ); \ _arg4 ? -_num : _num; \ }) diff --git a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh index da298394daa2..83552bb007b4 100755 --- a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh +++ b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh @@ -40,17 +40,24 @@ mkdir $T cat > $T/init << '__EOF___' #!/bin/sh # Run in userspace a few milliseconds every second. This helps to -# exercise the NO_HZ_FULL portions of RCU. +# exercise the NO_HZ_FULL portions of RCU. The 192 instances of "a" was +# empirically shown to give a nice multi-millisecond burst of user-mode +# execution on a 2GHz CPU, as desired. Modern CPUs will vary from a +# couple of milliseconds up to perhaps 100 milliseconds, which is an +# acceptable range. +# +# Why not calibrate an exact delay? Because within this initrd, we +# are restricted to Bourne-shell builtins, which as far as I know do not +# provide any means of obtaining a fine-grained timestamp. + +a4="a a a a" +a16="$a4 $a4 $a4 $a4" +a64="$a16 $a16 $a16 $a16" +a192="$a64 $a64 $a64" while : do q= - for i in \ - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a + for i in $a192 do q="$q $i" done @@ -124,8 +131,8 @@ if echo -e "#if __x86_64__||__i386__||__i486__||__i586__||__i686__" \ | grep -q '^yes'; then # architecture supported by nolibc ${CROSS_COMPILE}gcc -fno-asynchronous-unwind-tables -fno-ident \ - -nostdlib -include ../bin/nolibc.h -lgcc -s -static -Os \ - -o init init.c + -nostdlib -include ../../../../include/nolibc/nolibc.h \ + -lgcc -s -static -Os -o init init.c else ${CROSS_COMPILE}gcc -s -static -Os -o init init.c fi diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 5ecea812cb6a..28de87ff9f51 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4083,7 +4083,7 @@ static int kvm_suspend(void) static void kvm_resume(void) { if (kvm_usage_count) { - WARN_ON(raw_spin_is_locked(&kvm_count_lock)); + lockdep_assert_held(&kvm_count_lock); hardware_enable_nolock(NULL); } } |
