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* Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2019-05-061-86/+41
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - Make nohz housekeeping processing more permissive and less intrusive to isolated CPUs - Decouple CPU-bound workqueue acconting from the scheduler and move it into the workqueue code. - Optimize topology building - Better handle quota and period overflows - Add more RCU annotations - Comment updates, misc cleanups" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits) nohz_full: Allow the boot CPU to be nohz_full sched/isolation: Require a present CPU in housekeeping mask kernel/cpu: Allow non-zero CPU to be primary for suspend / kexec freeze power/suspend: Add function to disable secondaries for suspend sched/core: Allow the remote scheduler tick to be started on CPU0 sched/nohz: Run NOHZ idle load balancer on HK_FLAG_MISC CPUs sched/debug: Fix spelling mistake "logaritmic" -> "logarithmic" sched/topology: Update init_sched_domains() comment cgroup/cpuset: Update stale generate_sched_domains() comments sched/core: Check quota and period overflow at usec to nsec conversion sched/core: Handle overflow in cpu_shares_write_u64 sched/rt: Check integer overflow at usec to nsec conversion sched/core: Fix typo in comment sched/core: Make some functions static sched/core: Unify p->on_rq updates sched/core: Remove ttwu_activate() sched/core, workqueues: Distangle worker accounting from rq lock sched/fair: Remove unneeded prototype of capacity_of() sched/topology: Skip duplicate group rewrites in build_sched_groups() sched/topology: Fix build_sched_groups() comment ...
| * sched/core: Allow the remote scheduler tick to be started on CPU0Nicholas Piggin2019-05-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This has no effect yet because CPU0 will always be a housekeeping CPU until a later change. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linuxppc-dev@lists.ozlabs.org Link: https://lkml.kernel.org/r/20190411033448.20842-2-npiggin@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched/core: Check quota and period overflow at usec to nsec conversionKonstantin Khlebnikov2019-04-191-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Large values could overflow u64 and pass following sanity checks. # echo 18446744073750000 > cpu.cfs_period_us # cat cpu.cfs_period_us 40448 # echo 18446744073750000 > cpu.cfs_quota_us # cat cpu.cfs_quota_us 40448 After this patch they will fail with -EINVAL. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/155125502079.293431.3947497929372138600.stgit@buzz Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched/core: Handle overflow in cpu_shares_write_u64Konstantin Khlebnikov2019-04-191-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bit shift in scale_load() could overflow shares. This patch saturates it to MAX_SHARES like following sched_group_set_shares(). Example: # echo 9223372036854776832 > cpu.shares # cat cpu.shares Before patch: 1024 After pattch: 262144 Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/155125501891.293431.3345233332801109696.stgit@buzz Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched/core: Fix typo in commentJoel Savitz2019-04-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Joel Savitz <jsavitz@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: trivial@kernel.org Link: http://lkml.kernel.org/r/1551921213-813-1-git-send-email-jsavitz@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched/core: Make some functions staticYueHaibing2019-04-181-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix these sparse warnings: kernel/sched/core.c:6577:11: warning: symbol 'min_cfs_quota_period' was not declared. Should it be static? kernel/sched/core.c:6657:5: warning: symbol 'tg_set_cfs_quota' was not declared. Should it be static? kernel/sched/core.c:6670:6: warning: symbol 'tg_get_cfs_quota' was not declared. Should it be static? kernel/sched/core.c:6683:5: warning: symbol 'tg_set_cfs_period' was not declared. Should it be static? kernel/sched/core.c:6693:6: warning: symbol 'tg_get_cfs_period' was not declared. Should it be static? kernel/sched/fair.c:2596:6: warning: symbol 'task_tick_numa' was not declared. Should it be static? Signed-off-by: YueHaibing <yuehaibing@huawei.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20190418144713.34332-1-yuehaibing@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched/core: Unify p->on_rq updatesPeter Zijlstra2019-04-161-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Almost all {,de}activate_task() invocations pair with p->on_rq updates, the exception being the usage in rt/deadline which hold both rq locks and therefore don't strictly need to set TASK_ON_RQ_MIGRATING, but it is harmless if we do anyway. Put the updates in {,de}activate_task() and cut down on repetition. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched/core: Remove ttwu_activate()Peter Zijlstra2019-04-161-7/+2
| | | | | | | | | | | | | | | | | | | | | | After the removal of try_to_wake_up_local(), there is only one user of ttwu_activate() left, and since it is a trivial function, remove it. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched/core, workqueues: Distangle worker accounting from rq lockThomas Gleixner2019-04-161-67/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The worker accounting for CPU bound workers is plugged into the core scheduler code and the wakeup code. This is not a hard requirement and can be avoided by keeping track of the state in the workqueue code itself. Keep track of the sleeping state in the worker itself and call the notifier before entering the core scheduler. There might be false positives when the task is woken between that call and actually scheduling, but that's not really different from scheduling and being woken immediately after switching away. When nr_running is updated when the task is retunrning from schedule() then it is later compared when it is done from ttwu(). [ bigeasy: preempt_disable() around wq_worker_sleeping() by Daniel Bristot de Oliveira ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/ad2b29b5715f970bffc1a7026cabd6ff0b24076a.1532952814.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | ia64/tlb: Eradicate tlb_migrate_finish() callbackPeter Zijlstra2019-04-031-1/+0
|/ | | | | | | | | | | | | | | | | | | | | Only ia64-sn2 uses this as an optimization, and there it is of questionable correctness due to the mm_users==1 test. Remove it entirely. No change in behavior intended. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2019-03-241-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Thomas Gleixner: "Third more careful attempt for this set of fixes: - Prevent a 32bit math overflow in the cpufreq code - Fix a buffer overflow when scanning the cgroup2 cpu.max property - A set of fixes for the NOHZ scheduler logic to prevent waking up CPUs even if the capacity of the busy CPUs is sufficient along with other tweaks optimizing the behaviour for asymmetric systems (big/little)" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Skip LLC NOHZ logic for asymmetric systems sched/fair: Tune down misfit NOHZ kicks sched/fair: Comment some nohz_balancer_kick() kick conditions sched/core: Fix buffer overflow in cgroup2 property cpu.max sched/cpufreq: Fix 32-bit math overflow
| * sched/core: Fix buffer overflow in cgroup2 property cpu.maxKonstantin Khlebnikov2019-03-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add limit into sscanf format string for on-stack buffer. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 0d5936344f30 ("sched: Implement interface for cgroup unified hierarchy") Link: https://lkml.kernel.org/r/155189230232.2620.13120481613524200065.stgit@buzz Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2019-03-061-0/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc updates from Andrew Morton: - a few misc things - ocfs2 updates - most of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (159 commits) tools/testing/selftests/proc/proc-self-syscall.c: remove duplicate include proc: more robust bulk read test proc: test /proc/*/maps, smaps, smaps_rollup, statm proc: use seq_puts() everywhere proc: read kernel cpu stat pointer once proc: remove unused argument in proc_pid_lookup() fs/proc/thread_self.c: code cleanup for proc_setup_thread_self() fs/proc/self.c: code cleanup for proc_setup_self() proc: return exit code 4 for skipped tests mm,mremap: bail out earlier in mremap_to under map pressure mm/sparse: fix a bad comparison mm/memory.c: do_fault: avoid usage of stale vm_area_struct writeback: fix inode cgroup switching comment mm/huge_memory.c: fix "orig_pud" set but not used mm/hotplug: fix an imbalance with DEBUG_PAGEALLOC mm/memcontrol.c: fix bad line in comment mm/cma.c: cma_declare_contiguous: correct err handling mm/page_ext.c: fix an imbalance with kmemleak mm/compaction: pass pgdat to too_many_isolated() instead of zone mm: remove zone_lru_lock() function, access ->lru_lock directly ...
| * | mm, compaction: capture a page under direct compactionMel Gorman2019-03-051-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Compaction is inherently race-prone as a suitable page freed during compaction can be allocated by any parallel task. This patch uses a capture_control structure to isolate a page immediately when it is freed by a direct compactor in the slow path of the page allocator. The intent is to avoid redundant scanning. 5.0.0-rc1 5.0.0-rc1 selective-v3r17 capture-v3r19 Amean fault-both-1 0.00 ( 0.00%) 0.00 * 0.00%* Amean fault-both-3 2582.11 ( 0.00%) 2563.68 ( 0.71%) Amean fault-both-5 4500.26 ( 0.00%) 4233.52 ( 5.93%) Amean fault-both-7 5819.53 ( 0.00%) 6333.65 ( -8.83%) Amean fault-both-12 9321.18 ( 0.00%) 9759.38 ( -4.70%) Amean fault-both-18 9782.76 ( 0.00%) 10338.76 ( -5.68%) Amean fault-both-24 15272.81 ( 0.00%) 13379.55 * 12.40%* Amean fault-both-30 15121.34 ( 0.00%) 16158.25 ( -6.86%) Amean fault-both-32 18466.67 ( 0.00%) 18971.21 ( -2.73%) Latency is only moderately affected but the devil is in the details. A closer examination indicates that base page fault latency is reduced but latency of huge pages is increased as it takes creater care to succeed. Part of the "problem" is that allocation success rates are close to 100% even when under pressure and compaction gets harder 5.0.0-rc1 5.0.0-rc1 selective-v3r17 capture-v3r19 Percentage huge-3 96.70 ( 0.00%) 98.23 ( 1.58%) Percentage huge-5 96.99 ( 0.00%) 95.30 ( -1.75%) Percentage huge-7 94.19 ( 0.00%) 97.24 ( 3.24%) Percentage huge-12 94.95 ( 0.00%) 97.35 ( 2.53%) Percentage huge-18 96.74 ( 0.00%) 97.30 ( 0.58%) Percentage huge-24 97.07 ( 0.00%) 97.55 ( 0.50%) Percentage huge-30 95.69 ( 0.00%) 98.50 ( 2.95%) Percentage huge-32 96.70 ( 0.00%) 99.27 ( 2.65%) And scan rates are reduced as expected by 6% for the migration scanner and 29% for the free scanner indicating that there is less redundant work. Compaction migrate scanned 20815362 19573286 Compaction free scanned 16352612 11510663 [mgorman@techsingularity.net: remove redundant check] Link: http://lkml.kernel.org/r/20190201143853.GH9565@techsingularity.net Link: http://lkml.kernel.org/r/20190118175136.31341-23-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2019-03-061-5/+7
|\ \ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - refcount conversions - Solve the rq->leaf_cfs_rq_list can of worms for real. - improve power-aware scheduling - add sysctl knob for Energy Aware Scheduling - documentation updates - misc other changes" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits) kthread: Do not use TIMER_IRQSAFE kthread: Convert worker lock to raw spinlock sched/fair: Use non-atomic cpumask_{set,clear}_cpu() sched/fair: Remove unused 'sd' parameter from select_idle_smt() sched/wait: Use freezable_schedule() when possible sched/fair: Prune, fix and simplify the nohz_balancer_kick() comment block sched/fair: Explain LLC nohz kick condition sched/fair: Simplify nohz_balancer_kick() sched/topology: Fix percpu data types in struct sd_data & struct s_data sched/fair: Simplify post_init_entity_util_avg() by calling it with a task_struct pointer argument sched/fair: Fix O(nr_cgroups) in the load balancing path sched/fair: Optimize update_blocked_averages() sched/fair: Fix insertion in rq->leaf_cfs_rq_list sched/fair: Add tmp_alone_branch assertion sched/core: Use READ_ONCE()/WRITE_ONCE() in move_queued_task()/task_rq_lock() sched/debug: Initialize sd_sysctl_cpus if !CONFIG_CPUMASK_OFFSTACK sched/pelt: Skip updating util_est when utilization is higher than CPU's capacity sched/fair: Update scale invariance of PELT sched/fair: Move the rq_of() helper function sched/core: Convert task_struct.stack_refcount to refcount_t ...
| * | sched/fair: Simplify post_init_entity_util_avg() by calling it with a ↵Dietmar Eggemann2019-02-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | task_struct pointer argument Since commit: d03266910a53 ("sched/fair: Fix task group initialization") the utilization of a sched entity representing a task group is no longer initialized to any other value than 0. So post_init_entity_util_avg() is only used for tasks, not for sched_entities. Make this clear by calling it with a task_struct pointer argument which also eliminates the entity_is_task(se) if condition in the fork path and get rid of the stale comment in remove_entity_load_avg() accordingly. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Patrick Bellasi <patrick.bellasi@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Perret <quentin.perret@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Valentin Schneider <valentin.schneider@arm.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lkml.kernel.org/r/20190122162501.12000-1-dietmar.eggemann@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | Merge tag 'v5.0-rc6' into sched/core, to pick up fixesIngo Molnar2019-02-111-3/+16
| |\ \ | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | sched/core: Use READ_ONCE()/WRITE_ONCE() in move_queued_task()/task_rq_lock()Andrea Parri2019-02-041-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | move_queued_task() synchronizes with task_rq_lock() as follows: move_queued_task() task_rq_lock() [S] ->on_rq = MIGRATING [L] rq = task_rq() WMB (__set_task_cpu()) ACQUIRE (rq->lock); [S] ->cpu = new_cpu [L] ->on_rq where "[L] rq = task_rq()" is ordered before "ACQUIRE (rq->lock)" by an address dependency and, in turn, "ACQUIRE (rq->lock)" is ordered before "[L] ->on_rq" by the ACQUIRE itself. Use READ_ONCE() to load ->cpu in task_rq() (c.f., task_cpu()) to honor this address dependency. Also, mark the accesses to ->cpu and ->on_rq with READ_ONCE()/WRITE_ONCE() to comply with the LKMM. Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/20190121155240.27173-1-andrea.parri@amarulasolutions.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | sched/fair: Update scale invariance of PELTVincent Guittot2019-02-041-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current implementation of load tracking invariance scales the contribution with current frequency and uarch performance (only for utilization) of the CPU. One main result of this formula is that the figures are capped by current capacity of CPU. Another one is that the load_avg is not invariant because not scaled with uarch. The util_avg of a periodic task that runs r time slots every p time slots varies in the range : U * (1-y^r)/(1-y^p) * y^i < Utilization < U * (1-y^r)/(1-y^p) with U is the max util_avg value = SCHED_CAPACITY_SCALE At a lower capacity, the range becomes: U * C * (1-y^r')/(1-y^p) * y^i' < Utilization < U * C * (1-y^r')/(1-y^p) with C reflecting the compute capacity ratio between current capacity and max capacity. so C tries to compensate changes in (1-y^r') but it can't be accurate. Instead of scaling the contribution value of PELT algo, we should scale the running time. The PELT signal aims to track the amount of computation of tasks and/or rq so it seems more correct to scale the running time to reflect the effective amount of computation done since the last update. In order to be fully invariant, we need to apply the same amount of running time and idle time whatever the current capacity. Because running at lower capacity implies that the task will run longer, we have to ensure that the same amount of idle time will be applied when system becomes idle and no idle time has been "stolen". But reaching the maximum utilization value (SCHED_CAPACITY_SCALE) means that the task is seen as an always-running task whatever the capacity of the CPU (even at max compute capacity). In this case, we can discard this "stolen" idle times which becomes meaningless. In order to achieve this time scaling, a new clock_pelt is created per rq. The increase of this clock scales with current capacity when something is running on rq and synchronizes with clock_task when rq is idle. With this mechanism, we ensure the same running and idle time whatever the current capacity. This also enables to simplify the pelt algorithm by removing all references of uarch and frequency and applying the same contribution to utilization and loads. Furthermore, the scaling is done only once per update of clock (update_rq_clock_task()) instead of during each update of sched_entities and cfs/rt/dl_rq of the rq like the current implementation. This is interesting when cgroup are involved as shown in the results below: On a hikey (octo Arm64 platform). Performance cpufreq governor and only shallowest c-state to remove variance generated by those power features so we only track the impact of pelt algo. each test runs 16 times: ./perf bench sched pipe (higher is better) kernel tip/sched/core + patch ops/seconds ops/seconds diff cgroup root 59652(+/- 0.18%) 59876(+/- 0.24%) +0.38% level1 55608(+/- 0.27%) 55923(+/- 0.24%) +0.57% level2 52115(+/- 0.29%) 52564(+/- 0.22%) +0.86% hackbench -l 1000 (lower is better) kernel tip/sched/core + patch duration(sec) duration(sec) diff cgroup root 4.453(+/- 2.37%) 4.383(+/- 2.88%) -1.57% level1 4.859(+/- 8.50%) 4.830(+/- 7.07%) -0.60% level2 5.063(+/- 9.83%) 4.928(+/- 9.66%) -2.66% Then, the responsiveness of PELT is improved when CPU is not running at max capacity with this new algorithm. I have put below some examples of duration to reach some typical load values according to the capacity of the CPU with current implementation and with this patch. These values has been computed based on the geometric series and the half period value: Util (%) max capacity half capacity(mainline) half capacity(w/ patch) 972 (95%) 138ms not reachable 276ms 486 (47.5%) 30ms 138ms 60ms 256 (25%) 13ms 32ms 26ms On my hikey (octo Arm64 platform) with schedutil governor, the time to reach max OPP when starting from a null utilization, decreases from 223ms with current scale invariance down to 121ms with the new algorithm. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bsegall@google.com Cc: dietmar.eggemann@arm.com Cc: patrick.bellasi@arm.com Cc: pjt@google.com Cc: pkondeti@codeaurora.org Cc: quentin.perret@arm.com Cc: rjw@rjwysocki.net Cc: srinivas.pandruvada@linux.intel.com Cc: thara.gopinath@linaro.org Link: https://lkml.kernel.org/r/1548257214-13745-3-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | Merge branch 'locking-core-for-linus' of ↵Linus Torvalds2019-03-061-21/+46
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "The biggest part of this tree is the new auto-generated atomics API wrappers by Mark Rutland. The primary motivation was to allow instrumentation without uglifying the primary source code. The linecount increase comes from adding the auto-generated files to the Git space as well: include/asm-generic/atomic-instrumented.h | 1689 ++++++++++++++++-- include/asm-generic/atomic-long.h | 1174 ++++++++++--- include/linux/atomic-fallback.h | 2295 +++++++++++++++++++++++++ include/linux/atomic.h | 1241 +------------ I preferred this approach, so that the full call stack of the (already complex) locking APIs is still fully visible in 'git grep'. But if this is excessive we could certainly hide them. There's a separate build-time mechanism to determine whether the headers are out of date (they should never be stale if we do our job right). Anyway, nothing from this should be visible to regular kernel developers. Other changes: - Add support for dynamic keys, which removes a source of false positives in the workqueue code, among other things (Bart Van Assche) - Updates to tools/memory-model (Andrea Parri, Paul E. McKenney) - qspinlock, wake_q and lockdep micro-optimizations (Waiman Long) - misc other updates and enhancements" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits) locking/lockdep: Shrink struct lock_class_key locking/lockdep: Add module_param to enable consistency checks lockdep/lib/tests: Test dynamic key registration lockdep/lib/tests: Fix run_tests.sh kernel/workqueue: Use dynamic lockdep keys for workqueues locking/lockdep: Add support for dynamic keys locking/lockdep: Verify whether lock objects are small enough to be used as class keys locking/lockdep: Check data structure consistency locking/lockdep: Reuse lock chains that have been freed locking/lockdep: Fix a comment in add_chain_cache() locking/lockdep: Introduce lockdep_next_lockchain() and lock_chain_count() locking/lockdep: Reuse list entries that are no longer in use locking/lockdep: Free lock classes that are no longer in use locking/lockdep: Update two outdated comments locking/lockdep: Make it easy to detect whether or not inside a selftest locking/lockdep: Split lockdep_free_key_range() and lockdep_reset_lock() locking/lockdep: Initialize the locks_before and locks_after lists earlier locking/lockdep: Make zap_class() remove all matching lock order entries locking/lockdep: Reorder struct lock_class members locking/lockdep: Avoid that add_chain_cache() adds an invalid chain to the cache ...
| * | | | sched/wake_q: Reduce reference counting for special usersDavidlohr Bueso2019-02-041-16/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some users, specifically futexes and rwsems, required fixes that allowed the callers to be safe when wakeups occur before they are expected by wake_up_q(). Such scenarios also play games and rely on reference counting, and until now were pivoting on wake_q doing it. With the wake_q_add() call being moved down, this can no longer be the case. As such we end up with a a double task refcounting overhead; and these callers care enough about this (being rather core-ish). This patch introduces a wake_q_add_safe() call that serves for callers that have already done refcounting and therefore the task is 'safe' from wake_q point of view (int that it requires reference throughout the entire queue/>wakeup cycle). In the one case it has internal reference counting, in the other case it consumes the reference counting. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Xie Yongji <xieyongji@baidu.com> Cc: Yongji Xie <elohimes@gmail.com> Cc: andrea.parri@amarulasolutions.com Cc: lilin24@baidu.com Cc: liuqi16@baidu.com Cc: nixun@baidu.com Cc: yuanlinsi01@baidu.com Cc: zhangyu31@baidu.com Link: https://lkml.kernel.org/r/20181218195352.7orq3upiwfdbrdne@linux-r8p5 Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | Revert "sched/core: Take the hotplug lock in sched_init_smp()"Valentin Schneider2019-01-211-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 40fa3780bac2b654edf23f6b13f4e2dd550aea10. Now that we have a system-wide muting of hotplug lockdep during init, this is no longer needed. Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: cai@gmx.us Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: linux-arm-kernel@lists.infradead.org Cc: longman@redhat.com Cc: marc.zyngier@arm.com Cc: mark.rutland@arm.com Link: https://lkml.kernel.org/r/1545243796-23224-3-git-send-email-valentin.schneider@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | sched/wake_q: Add branch prediction hint to wake_q_add() cmpxchgDavidlohr Bueso2019-01-211-1/+1
| | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cmpxchg() will fail when the task is already in the process of waking up, and as such is an extremely rare occurrence. Micro-optimize the call and put an unlikely() around it. To no surprise, when using CONFIG_PROFILE_ANNOTATED_BRANCHES under a number of workloads the incorrect rate was a mere 1-2%. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Waiman Long <longman@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Yongji Xie <elohimes@gmail.com> Cc: andrea.parri@amarulasolutions.com Cc: lilin24@baidu.com Cc: liuqi16@baidu.com Cc: nixun@baidu.com Cc: xieyongji@baidu.com Cc: yuanlinsi01@baidu.com Cc: zhangyu31@baidu.com Link: https://lkml.kernel.org/r/20181203053130.gwkw6kg72azt2npb@linux-r8p5 Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | Merge branch 'timers-2038-for-linus' of ↵Linus Torvalds2019-03-051-3/+2
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull year 2038 updates from Thomas Gleixner: "Another round of changes to make the kernel ready for 2038. After lots of preparatory work this is the first set of syscalls which are 2038 safe: 403 clock_gettime64 404 clock_settime64 405 clock_adjtime64 406 clock_getres_time64 407 clock_nanosleep_time64 408 timer_gettime64 409 timer_settime64 410 timerfd_gettime64 411 timerfd_settime64 412 utimensat_time64 413 pselect6_time64 414 ppoll_time64 416 io_pgetevents_time64 417 recvmmsg_time64 418 mq_timedsend_time64 419 mq_timedreceiv_time64 420 semtimedop_time64 421 rt_sigtimedwait_time64 422 futex_time64 423 sched_rr_get_interval_time64 The syscall numbers are identical all over the architectures" * 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) riscv: Use latest system call ABI checksyscalls: fix up mq_timedreceive and stat exceptions unicore32: Fix __ARCH_WANT_STAT64 definition asm-generic: Make time32 syscall numbers optional asm-generic: Drop getrlimit and setrlimit syscalls from default list 32-bit userspace ABI: introduce ARCH_32BIT_OFF_T config option compat ABI: use non-compat openat and open_by_handle_at variants y2038: add 64-bit time_t syscalls to all 32-bit architectures y2038: rename old time and utime syscalls y2038: remove struct definition redirects y2038: use time32 syscall names on 32-bit syscalls: remove obsolete __IGNORE_ macros y2038: syscalls: rename y2038 compat syscalls x86/x32: use time64 versions of sigtimedwait and recvmmsg timex: change syscalls to use struct __kernel_timex timex: use __kernel_timex internally sparc64: add custom adjtimex/clock_adjtime functions time: fix sys_timer_settime prototype time: Add struct __kernel_timex time: make adjtime compat handling available for 32 bit ...
| * | | Merge tag 'y2038-new-syscalls' of ↵Thomas Gleixner2019-02-101-3/+2
| |\ \ \ | | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground into timers/2038 Pull y2038 - time64 system calls from Arnd Bergmann: This series finally gets us to the point of having system calls with 64-bit time_t on all architectures, after a long time of incremental preparation patches. There was actually one conversion that I missed during the summer, i.e. Deepa's timex series, which I now updated based the 5.0-rc1 changes and review comments. The following system calls are now added on all 32-bit architectures using the same system call numbers: 403 clock_gettime64 404 clock_settime64 405 clock_adjtime64 406 clock_getres_time64 407 clock_nanosleep_time64 408 timer_gettime64 409 timer_settime64 410 timerfd_gettime64 411 timerfd_settime64 412 utimensat_time64 413 pselect6_time64 414 ppoll_time64 416 io_pgetevents_time64 417 recvmmsg_time64 418 mq_timedsend_time64 419 mq_timedreceiv_time64 420 semtimedop_time64 421 rt_sigtimedwait_time64 422 futex_time64 423 sched_rr_get_interval_time64 Each one of these corresponds directly to an existing system call that includes a 'struct timespec' argument, or a structure containing a timespec or (in case of clock_adjtime) timeval. Not included here are new versions of getitimer/setitimer and getrusage/waitid, which are planned for the future but only needed to make a consistent API rather than for correct operation beyond y2038. These four system calls are based on 'timeval', and it has not been finally decided what the replacement kernel interface will use instead. So far, I have done a lot of build testing across most architectures, which has found a number of bugs. Runtime testing so far included testing LTP on 32-bit ARM with the existing system calls, to ensure we do not regress for existing binaries, and a test with a 32-bit x86 build of LTP against a modified version of the musl C library that has been adapted to the new system call interface [3]. This library can be used for testing on all architectures supported by musl-1.1.21, but it is not how the support is getting integrated into the official musl release. Official musl support is planned but will require more invasive changes to the library. Link: https://lore.kernel.org/lkml/20190110162435.309262-1-arnd@arndb.de/T/ Link: https://lore.kernel.org/lkml/20190118161835.2259170-1-arnd@arndb.de/ Link: https://git.linaro.org/people/arnd/musl-y2038.git/ [2]
| | * | y2038: syscalls: rename y2038 compat syscallsArnd Bergmann2019-02-071-3/+2
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A lot of system calls that pass a time_t somewhere have an implementation using a COMPAT_SYSCALL_DEFINEx() on 64-bit architectures, and have been reworked so that this implementation can now be used on 32-bit architectures as well. The missing step is to redefine them using the regular SYSCALL_DEFINEx() to get them out of the compat namespace and make it possible to build them on 32-bit architectures. Any system call that ends in 'time' gets a '32' suffix on its name for that version, while the others get a '_time32' suffix, to distinguish them from the normal version, which takes a 64-bit time argument in the future. In this step, only 64-bit architectures are changed, doing this rename first lets us avoid touching the 32-bit architectures twice. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
* | / bpf: check that BPF programs run with preemption disabledPeter Zijlstra2019-02-191-0/+28
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce cant_sleep() macro for annotation of functions that cannot sleep. Use it in BPF_PROG_RUN to catch execution of BPF programs in preemptable context. Suggested-by: Jann Horn <jannh@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | sched/wake_q: Fix wakeup ordering for wake_qPeter Zijlstra2019-01-211-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Notable cmpxchg() does not provide ordering when it fails, however wake_q_add() requires ordering in this specific case too. Without this it would be possible for the concurrent wakeup to not observe our prior state. Andrea Parri provided: C wake_up_q-wake_q_add { int next = 0; int y = 0; } P0(int *next, int *y) { int r0; /* in wake_up_q() */ WRITE_ONCE(*next, 1); /* node->next = NULL */ smp_mb(); /* implied by wake_up_process() */ r0 = READ_ONCE(*y); } P1(int *next, int *y) { int r1; /* in wake_q_add() */ WRITE_ONCE(*y, 1); /* wake_cond = true */ smp_mb__before_atomic(); r1 = cmpxchg_relaxed(next, 1, 2); } exists (0:r0=0 /\ 1:r1=0) This "exists" clause cannot be satisfied according to the LKMM: Test wake_up_q-wake_q_add Allowed States 3 0:r0=0; 1:r1=1; 0:r0=1; 1:r1=0; 0:r0=1; 1:r1=1; No Witnesses Positive: 0 Negative: 3 Condition exists (0:r0=0 /\ 1:r1=0) Observation wake_up_q-wake_q_add Never 0 3 Reported-by: Yongji Xie <elohimes@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched/wake_q: Document wake_q_add()Peter Zijlstra2019-01-211-0/+12
|/ | | | | | | | | | | | | | | | | | | | | | | | The only guarantee provided by wake_q_add() is that a wakeup will happen after it, it does _NOT_ guarantee the wakeup will be delayed until the matching wake_up_q(). If wake_q_add() fails the cmpxchg() a concurrent wakeup is pending and that can happen at any time after the cmpxchg(). This means we should not rely on the wakeup happening at wake_q_up(), but should be ready for wake_q_add() to issue the wakeup. The delay; if provided (most likely); should only result in more efficient behaviour. Reported-by: Yongji Xie <elohimes@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* jump_label: move 'asm goto' support test to KconfigMasahiro Yamada2019-01-061-1/+1
| | | | | | | | | | | | | | | | | | | | | Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2019-01-051-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge more updates from Andrew Morton: - procfs updates - various misc bits - lib/ updates - epoll updates - autofs - fatfs - a few more MM bits * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (58 commits) mm/page_io.c: fix polled swap page in checkpatch: add Co-developed-by to signature tags docs: fix Co-Developed-by docs drivers/base/platform.c: kmemleak ignore a known leak fs: don't open code lru_to_page() fs/: remove caller signal_pending branch predictions mm/: remove caller signal_pending branch predictions arch/arc/mm/fault.c: remove caller signal_pending_branch predictions kernel/sched/: remove caller signal_pending branch predictions kernel/locking/mutex.c: remove caller signal_pending branch predictions mm: select HAVE_MOVE_PMD on x86 for faster mremap mm: speed up mremap by 20x on large regions mm: treewide: remove unused address argument from pte_alloc functions initramfs: cleanup incomplete rootfs scripts/gdb: fix lx-version string output kernel/kcov.c: mark write_comp_data() as notrace kernel/sysctl: add panic_print into sysctl panic: add options to print system info when panic happens bfs: extra sanity checking and static inode bitmap exec: separate MM_ANONPAGES and RLIMIT_STACK accounting ...
| * kernel/sched/: remove caller signal_pending branch predictionsDavidlohr Bueso2019-01-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | This is already done for us internally by the signal machinery. Link: http://lkml.kernel.org/r/20181116002713.8474-3-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Remove 'type' argument from access_ok() functionLinus Torvalds2019-01-031-2/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2018-12-261-3/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - Introduce "Energy Aware Scheduling" - by Quentin Perret. This is a coherent topology description of CPUs in cooperation with the PM subsystem, with the goal to schedule more energy-efficiently on asymetric SMP platform - such as waking up tasks to the more energy-efficient CPUs first, as long as the system isn't oversubscribed. For details of the design, see: https://lore.kernel.org/lkml/20180724122521.22109-1-quentin.perret@arm.com/ - Misc cleanups and smaller enhancements" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) sched/fair: Select an energy-efficient CPU on task wake-up sched/fair: Introduce an energy estimation helper function sched/fair: Add over-utilization/tipping point indicator sched/fair: Clean-up update_sg_lb_stats parameters sched/toplogy: Introduce the 'sched_energy_present' static key sched/topology: Make Energy Aware Scheduling depend on schedutil sched/topology: Disable EAS on inappropriate platforms sched/topology: Add lowest CPU asymmetry sched_domain level pointer sched/topology: Reference the Energy Model of CPUs when available PM: Introduce an Energy Model management framework sched/cpufreq: Prepare schedutil for Energy Aware Scheduling sched/topology: Relocate arch_scale_cpu_capacity() to the internal header sched/core: Remove unnecessary unlikely() in push_*_task() sched/topology: Remove the ::smt_gain field from 'struct sched_domain' sched: Fix various typos in comments sched/core: Clean up the #ifdef block in add_nr_running() sched/fair: Make some variables static sched/core: Create task_has_idle_policy() helper sched/fair: Add lsub_positive() and use it consistently sched/fair: Mask UTIL_AVG_UNCHANGED usages ...
| * sched: Fix various typos in commentsIngo Molnar2018-12-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Go over the scheduler source code and fix common typos in comments - and a typo in an actual variable name. No change in functionality intended. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * Merge tag 'v4.20-rc5' into sched/core, to pick up fixesIngo Molnar2018-12-031-29/+24
| |\ | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | sched/core: Create task_has_idle_policy() helperViresh Kumar2018-11-121-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We already have task_has_rt_policy() and task_has_dl_policy() helpers, create task_has_idle_policy() as well and update sched core to start using it. While at it, use task_has_dl_policy() at one more place. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: http://lkml.kernel.org/r/ce3915d5b490fc81af926a3b6bfb775e7188e005.1541416894.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | Merge branch 'for-mingo' of ↵Ingo Molnar2018-12-041-1/+1
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU changes from Paul E. McKenney: - Convert RCU's BUG_ON() and similar calls to WARN_ON() and similar. - Replace calls of RCU-bh and RCU-sched update-side functions to their vanilla RCU counterparts. This series is a step towards complete removal of the RCU-bh and RCU-sched update-side functions. ( Note that some of these conversions are going upstream via their respective maintainers. ) - Documentation updates, including a number of flavor-consolidation updates from Joel Fernandes. - Miscellaneous fixes. - Automate generation of the initrd filesystem used for rcutorture testing. - Convert spin_is_locked() assertions to instead use lockdep. ( Note that some of these conversions are going upstream via their respective maintainers. ) - SRCU updates, especially including a fix from Dennis Krein for a bag-on-head-class bug. - RCU torture-test updates. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | rcu: Eliminate synchronize_rcu_mult()Paul E. McKenney2018-11-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that synchronize_rcu() waits for both RCU read-side critical sections and preempt-disabled regions of code, the sole caller of synchronize_rcu_mult() can be replaced by synchronize_rcu(). This patch makes this change and removes synchronize_rcu_mult(). Note that _wait_rcu_gp() still supports synchronize_rcu_mult(), and thus might be simplified in the future to take only take a single call_rcu() function rather than the current list of them. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
* | | sched/smt: Make sched_smt_present track topologyPeter Zijlstra (Intel)2018-11-281-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the 'sched_smt_present' static key is enabled when at CPU bringup SMT topology is observed, but it is never disabled. However there is demand to also disable the key when the topology changes such that there is no SMT present anymore. Implement this by making the key count the number of cores that have SMT enabled. In particular, the SMT topology bits are set before interrrupts are enabled and similarly, are cleared after interrupts are disabled for the last time and the CPU dies. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185004.246110444@linutronix.de
* | | Merge branch 'sched/urgent' of ↵Linus Torvalds2018-11-111-1/+4
|\ \ \ | |/ / |/| / | |/ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Thomas Gleixner: "Two small scheduler fixes: - Take hotplug lock in sched_init_smp(). Technically not really required, but lockdep will complain other. - Trivial comment fix in sched/fair" * 'sched/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Fix a comment in task_numa_fault() sched/core: Take the hotplug lock in sched_init_smp()
| * sched/core: Take the hotplug lock in sched_init_smp()Valentin Schneider2018-11-041-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When running on linux-next (8c60c36d0b8c ("Add linux-next specific files for 20181019")) + CONFIG_PROVE_LOCKING=y on a big.LITTLE system (e.g. Juno or HiKey960), we get the following report: [ 0.748225] Call trace: [ 0.750685] lockdep_assert_cpus_held+0x30/0x40 [ 0.755236] static_key_enable_cpuslocked+0x20/0xc8 [ 0.760137] build_sched_domains+0x1034/0x1108 [ 0.764601] sched_init_domains+0x68/0x90 [ 0.768628] sched_init_smp+0x30/0x80 [ 0.772309] kernel_init_freeable+0x278/0x51c [ 0.776685] kernel_init+0x10/0x108 [ 0.780190] ret_from_fork+0x10/0x18 The static_key in question is 'sched_asym_cpucapacity' introduced by commit: df054e8445a4 ("sched/topology: Add static_key for asymmetric CPU capacity optimizations") In this particular case, we enable it because smp_prepare_cpus() will end up fetching the capacity-dmips-mhz entry from the devicetree, so we already have some asymmetry detected when entering sched_init_smp(). This didn't get detected in tip/sched/core because we were missing: commit cb538267ea1e ("jump_label/lockdep: Assert we hold the hotplug lock for _cpuslocked() operations") Calls to build_sched_domains() post sched_init_smp() will hold the hotplug lock, it just so happens that this very first call is a special case. As stated by a comment in sched_init_smp(), "There's no userspace yet to cause hotplug operations" so this is a harmless warning. However, to both respect the semantics of underlying callees and make lockdep happy, take the hotplug lock in sched_init_smp(). This also satisfies the comment atop sched_init_domains() that says "Callers must hold the hotplug lock". Reported-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Dietmar.Eggemann@arm.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: morten.rasmussen@arm.com Cc: quentin.perret@arm.com Link: http://lkml.kernel.org/r/1540301851-3048-1-git-send-email-valentin.schneider@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge tag 'pm-4.20-rc1-2' of ↵Linus Torvalds2018-10-301-21/+13
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management updates from Rafael Wysocki: "These remove a questionable heuristic from the menu cpuidle governor, fix a recent build regression in the intel_pstate driver, clean up ARM big-Little support in cpufreq and fix up hung task watchdog's interaction with system-wide power management transitions. Specifics: - Fix build regression in the intel_pstate driver that doesn't build without CONFIG_ACPI after recent changes (Dominik Brodowski). - One of the heuristics in the menu cpuidle governor is based on a function returning 0 most of the time, so drop it and clean up the scheduler code related to it (Daniel Lezcano). - Prevent the arm_big_little cpufreq driver from being used on ARM64 which is not suitable for it and drop the arm_big_little_dt driver that is not used any more (Sudeep Holla). - Prevent the hung task watchdog from triggering during resume from system-wide sleep states by disabling it before freezing tasks and enabling it again after they have been thawed (Vitaly Kuznetsov)" * tag 'pm-4.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: kernel: hung_task.c: disable on suspend cpufreq: remove unused arm_big_little_dt driver cpufreq: drop ARM_BIG_LITTLE_CPUFREQ support for ARM64 cpufreq: intel_pstate: Fix compilation for !CONFIG_ACPI cpuidle: menu: Remove get_loadavg() from the performance multiplier sched: Factor out nr_iowait and nr_iowait_cpu
| * cpuidle: menu: Remove get_loadavg() from the performance multiplierDaniel Lezcano2018-10-251-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function get_loadavg() returns almost always zero. To be more precise, statistically speaking for a total of 1023379 times passing in the function, the load is equal to zero 1020728 times, greater than 100, 610 times, the remaining is between 0 and 5. In 2011, the get_loadavg() was removed from the Android tree because of the above [1]. At this time, the load was: unsigned long this_cpu_load(void) { struct rq *this = this_rq(); return this->cpu_load[0]; } In 2014, the code was changed by commit 372ba8cb46b2 (cpuidle: menu: Lookup CPU runqueues less) and the load is: void get_iowait_load(unsigned long *nr_waiters, unsigned long *load) { struct rq *rq = this_rq(); *nr_waiters = atomic_read(&rq->nr_iowait); *load = rq->load.weight; } with the same result. Both measurements show using the load in this code path does no matter anymore. Removing it. [1] https://android.googlesource.com/kernel/common/+/4dedd9f124703207895777ac6e91dacde0f7cc17 Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * sched: Factor out nr_iowait and nr_iowait_cpuDaniel Lezcano2018-10-251-21/+20
| | | | | | | | | | | | | | | | | | | | | | The function nr_iowait_cpu() can be used directly by nr_iowait() instead of duplicating code. Call nr_iowait_cpu() from nr_iowait() Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | psi: pressure stall information for CPU, memory, and IOJohannes Weiner2018-10-261-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When systems are overcommitted and resources become contended, it's hard to tell exactly the impact this has on workload productivity, or how close the system is to lockups and OOM kills. In particular, when machines work multiple jobs concurrently, the impact of overcommit in terms of latency and throughput on the individual job can be enormous. In order to maximize hardware utilization without sacrificing individual job health or risk complete machine lockups, this patch implements a way to quantify resource pressure in the system. A kernel built with CONFIG_PSI=y creates files in /proc/pressure/ that expose the percentage of time the system is stalled on CPU, memory, or IO, respectively. Stall states are aggregate versions of the per-task delay accounting delays: cpu: some tasks are runnable but not executing on a CPU memory: tasks are reclaiming, or waiting for swapin or thrashing cache io: tasks are waiting for io completions These percentages of walltime can be thought of as pressure percentages, and they give a general sense of system health and productivity loss incurred by resource overcommit. They can also indicate when the system is approaching lockup scenarios and OOMs. To do this, psi keeps track of the task states associated with each CPU and samples the time they spend in stall states. Every 2 seconds, the samples are averaged across CPUs - weighted by the CPUs' non-idle time to eliminate artifacts from unused CPUs - and translated into percentages of walltime. A running average of those percentages is maintained over 10s, 1m, and 5m periods (similar to the loadaverage). [hannes@cmpxchg.org: doc fixlet, per Randy] Link: http://lkml.kernel.org/r/20180828205625.GA14030@cmpxchg.org [hannes@cmpxchg.org: code optimization] Link: http://lkml.kernel.org/r/20180907175015.GA8479@cmpxchg.org [hannes@cmpxchg.org: rename psi_clock() to psi_update_work(), per Peter] Link: http://lkml.kernel.org/r/20180907145404.GB11088@cmpxchg.org [hannes@cmpxchg.org: fix build] Link: http://lkml.kernel.org/r/20180913014222.GA2370@cmpxchg.org Link: http://lkml.kernel.org/r/20180828172258.3185-9-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Drake <drake@endlessm.com> Tested-by: Suren Baghdasaryan <surenb@google.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | sched: introduce this_rq_lock_irq()Johannes Weiner2018-10-261-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | do_sched_yield() disables IRQs, looks up this_rq() and locks it. The next patch is adding another site with the same pattern, so provide a convenience function for it. Link: http://lkml.kernel.org/r/20180828172258.3185-8-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Suren Baghdasaryan <surenb@google.com> Tested-by: Daniel Drake <drake@endlessm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'timers-core-for-linus' of ↵Linus Torvalds2018-10-251-4/+4
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timekeeping updates from Thomas Gleixner: "The timers and timekeeping departement provides: - Another large y2038 update with further preparations for providing the y2038 safe timespecs closer to the syscalls. - An overhaul of the SHCMT clocksource driver - SPDX license identifier updates - Small cleanups and fixes all over the place" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) tick/sched : Remove redundant cpu_online() check clocksource/drivers/dw_apb: Add reset control clocksource: Remove obsolete CLOCKSOURCE_OF_DECLARE clocksource/drivers: Unify the names to timer-* format clocksource/drivers/sh_cmt: Add R-Car gen3 support dt-bindings: timer: renesas: cmt: document R-Car gen3 support clocksource/drivers/sh_cmt: Properly line-wrap sh_cmt_of_table[] initializer clocksource/drivers/sh_cmt: Fix clocksource width for 32-bit machines clocksource/drivers/sh_cmt: Fixup for 64-bit machines clocksource/drivers/sh_tmu: Convert to SPDX identifiers clocksource/drivers/sh_mtu2: Convert to SPDX identifiers clocksource/drivers/sh_cmt: Convert to SPDX identifiers clocksource/drivers/renesas-ostm: Convert to SPDX identifiers clocksource: Convert to using %pOFn instead of device_node.name tick/broadcast: Remove redundant check RISC-V: Request newstat syscalls y2038: signal: Change rt_sigtimedwait to use __kernel_timespec y2038: socket: Change recvmmsg to use __kernel_timespec y2038: sched: Change sched_rr_get_interval to use __kernel_timespec y2038: utimes: Rework #ifdef guards for compat syscalls ...
| * y2038: sched: Change sched_rr_get_interval to use __kernel_timespecArnd Bergmann2018-08-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | This is a preparation patch for converting sys_sched_rr_get_interval to work with 64-bit time_t on 32-bit architectures. The 'interval' argument is changed to struct __kernel_timespec, which will be redefined using 64-bit time_t in the future. The compat version of the system call in turn is enabled for compilation with CONFIG_COMPAT_32BIT_TIME so the individual 32-bit architectures can share the handling of the traditional argument with 64-bit architectures providing it for their compat mode. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
| * y2038: globally rename compat_time to old_time32Arnd Bergmann2018-08-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Christoph Hellwig suggested a slightly different path for handling backwards compatibility with the 32-bit time_t based system calls: Rather than simply reusing the compat_sys_* entry points on 32-bit architectures unchanged, we get rid of those entry points and the compat_time types by renaming them to something that makes more sense on 32-bit architectures (which don't have a compat mode otherwise), and then share the entry points under the new name with the 64-bit architectures that use them for implementing the compatibility. The following types and interfaces are renamed here, and moved from linux/compat_time.h to linux/time32.h: old new --- --- compat_time_t old_time32_t struct compat_timeval struct old_timeval32 struct compat_timespec struct old_timespec32 struct compat_itimerspec struct old_itimerspec32 ns_to_compat_timeval() ns_to_old_timeval32() get_compat_itimerspec64() get_old_itimerspec32() put_compat_itimerspec64() put_old_itimerspec32() compat_get_timespec64() get_old_timespec32() compat_put_timespec64() put_old_timespec32() As we already have aliases in place, this patch addresses only the instances that are relevant to the system call interface in particular, not those that occur in device drivers and other modules. Those will get handled separately, while providing the 64-bit version of the respective interfaces. I'm not renaming the timex, rusage and itimerval structures, as we are still debating what the new interface will look like, and whether we will need a replacement at all. This also doesn't change the names of the syscall entry points, which can be done more easily when we actually switch over the 32-bit architectures to use them, at that point we need to change COMPAT_SYSCALL_DEFINEx to SYSCALL_DEFINEx with a new name, e.g. with a _time32 suffix. Suggested-by: Christoph Hellwig <hch@infradead.org> Link: https://lore.kernel.org/lkml/20180705222110.GA5698@infradead.org/ Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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