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| * | tracing: Remove access to trace_flags in trace_printk.cSteven Rostedt (Red Hat)2015-09-303-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the effort to move the global trace_flags to the tracing instances, the direct access to trace_flags must be removed from trace_printk.c Instead, add a new trace_printk_enabled boolean that is set by a new access function trace_printk_control(), that will enable or disable trace_printk. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Add build bug if we have more trace_flags than bitsSteven Rostedt (Red Hat)2015-09-302-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add a enum that denotes the last bit of the trace_flags and have a BUILD_BUG_ON(last_bit > 32). If we add more bits than we have in trace_flags, the kernel wont build. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Always show all tracer options in the options directorySteven Rostedt (Red Hat)2015-09-302-34/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are options that are unique to a specific tracer (like function and function graph). Currently, these options are only visible in the options directory when the tracer is enabled. This has been a pain, especially for something like the func_stack_trace option that if used inappropriately, could bring the system to a crawl. But the only way to see it, is to enable the function tracer. For example, if one had done: # cd /sys/kernel/tracing # echo __schedule > set_ftrace_filter # echo 1 > options/func_stack_trace # echo function > current_tracer The __schedule call will be traced and a stack trace will also be recorded there. Now when you were done, you may do... # echo nop > current_tracer # echo > set_ftrace_filter But you forgot to disable the func_stack_trace. The only way to disable it is to re-enable function tracing first. If you do not add a filter to set_ftrace_filter and just do: # echo function > current_tracer Now you would be performing a stack trace on *every* function! On some systems, that causes a live lock. Others may take a few minutes to fix your mistake. Having the func_stack_trace option visible allows you to check it and disable it before enabling the funtion tracer. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Only create stacktrace option when STACKTRACE is configuredSteven Rostedt (Red Hat)2015-09-292-14/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Only create the stacktrace trace option when CONFIG_STACKTRACE is configured. Cleaned up the ftrace_trace_stack() function call a little to allow better encapsulation of the stacktrace trace flag. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Do not create function tracer options when not compiled inSteven Rostedt (Red Hat)2015-09-294-22/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | When the function tracer is not compiled in, do not create the option files for it. Fix up both the sched_wakeup and irqsoff tracers to handle the change. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Only create branch tracer options when compiled inSteven Rostedt (Red Hat)2015-09-291-2/+9
| | | | | | | | | | | | | | | | | | | | | When the branch tracer is not compiled in, do not create the option files associated to it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Only create function graph options when it is compiled inSteven Rostedt (Red Hat)2015-09-294-11/+32
| | | | | | | | | | | | | | | | | | | | | Do not create fuction graph tracer options when function graph tracer is not even compiled in. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Use TRACE_FLAGS macro to keep enums and strings matchedSteven Rostedt (Red Hat)2015-09-292-83/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use a cute little macro trick to keep the names of the trace flags file guaranteed to match the corresponding masks. The macro TRACE_FLAGS is defined as a serious of enum names followed by the string name of the file that matches it. For example: #define TRACE_FLAGS \ C(PRINT_PARENT, "print-parent"), \ C(SYM_OFFSET, "sym-offset"), \ C(SYM_ADDR, "sym-addr"), \ C(VERBOSE, "verbose"), Now we can define the following: #undef C #define C(a, b) TRACE_ITER_##a##_BIT enum trace_iterator_bits { TRACE_FLAGS }; The above creates: enum trace_iterator_bits { TRACE_ITER_PRINT_PARENT_BIT, TRACE_ITER_SYM_OFFSET_BIT, TRACE_ITER_SYM_ADDR_BIT, TRACE_ITER_VERBOSE_BIT, }; Then we can redefine C as: #undef C #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT) enum trace_iterator_flags { TRACE_FLAGS }; Which creates: enum trace_iterator_flags { TRACE_ITER_PRINT_PARENT = (1 << TRACE_ITER_PRINT_PARENT_BIT), TRACE_ITER_SYM_OFFSET = (1 << TRACE_ITER_SYM_OFFSET_BIT), TRACE_ITER_SYM_ADDR = (1 << TRACE_ITER_SYM_ADDR_BIT), TRACE_ITER_VERBOSE = (1 << TRACE_ITER_VERBOSE_BIT), }; Then finally we can create the list of file names: #undef C #define C(a, b) b static const char *trace_options[] = { TRACE_FLAGS NULL }; Which creates: static const char *trace_options[] = { "print-parent", "sym-offset", "sym-addr", "verbose", NULL }; The importance of this is that the strings match the bit index. trace_options[TRACE_ITER_SYM_ADDR_BIT] == "sym-addr" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Use enums instead of hard coded bitmasks for TRACE_ITER flagsSteven Rostedt (Red Hat)2015-09-291-26/+55
| | | | | | | | | | | | | | | | | | | | | | | | Using enums with FLAG_BIT and then defining a FLAG = (1 << FLAG_BIT), is a bit more robust as we require that there are no bits out of order or skipped to match the file names that represent the bits. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Remove unused tracing option "ftrace_preempt"Steven Rostedt (Red Hat)2015-09-292-18/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There was a time where the function tracing would disable interrupts unless specifically told not to, where it would only disable preemption. With the new lockless code, the function tracing never disalbes interrupts and just uses disabling of preemption. Remove the option "ftrace_preempt" as it does nothing anyway. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Move "display-graph" option to main optionsSteven Rostedt (Red Hat)2015-09-294-64/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to facilitate making all tracer options visible even when the tracer is not active, we need to get rid of duplicate options. Any option that is shared between multiple tracers really should be a main option. As the wakeup and irqsoff tracers both use the "display-graph" option, and use it exactly the same way, move that option from the tracer options to the main options and consolidate them. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Turn seq_print_user_ip() into a static functionSteven Rostedt (Red Hat)2015-09-282-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | seq_print_user_ip() is used in only one location in one file. Turn it into a static function. We could inject its code into the caller, but that would make the code a bit too complex. Keep the code separate. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Inject seq_print_userip_objs() into its only userSteven Rostedt (Red Hat)2015-09-282-47/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | seq_print_userip_objs() is used only in one location, in one file. Instead of having it as an external function, go one further than making it static, but inject is code into its only user. It doesn't make the calling function much more complex. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Make ftrace_trace_stack() staticSteven Rostedt (Red Hat)2015-09-282-9/+9
| | | | | | | | | | | | | | | | | | | | | ftrace_trace_stack() is not called outside of trace.c. Make it a static function. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Pass trace_array into trace_buffer_unlock_commit()Steven Rostedt (Red Hat)2015-09-255-20/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for having trace options be per instance, the trace_array needs to be passed to the trace_buffer_unlock_commit(). The trace_event_buffer_lock_reserve() already passes in the trace_event_file where the trace_array can be derived from. Also added a "__init" to the boot up test event plus function tracing function function_test_events_call(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Remove unused function trace_current_buffer_lock_reserve()Steven Rostedt (Red Hat)2015-09-251-8/+0
| | | | | | | | | | | | | | | | | | | | | trace_current_buffer_lock_reserve() is not used by anything. Might as well get rid of it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Remove ftrace_trace_stack_regs()Steven Rostedt (Red Hat)2015-09-252-19/+14
| | | | | | | | | | | | | | | | | | | | | | | | ftrace_trace_stack_regs() is used in only one place, and because that is such a simple function, just move its code into the location that it was used in (trace_buffer_unlock_commit_regs()). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | kernel/trace_probe: is_good_name can be booleanYaowei Bai2015-09-221-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes is_good_name return bool to improve readability due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1442929393-4753-2-git-send-email-bywxiaobai@163.com Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | Merge branch 'for-4.4/core' of git://git.kernel.dk/linux-blockLinus Torvalds2015-11-041-11/+5
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull core block updates from Jens Axboe: "This is the core block pull request for 4.4. I've got a few more topic branches this time around, some of them will layer on top of the core+drivers changes and will come in a separate round. So not a huge chunk of changes in this round. This pull request contains: - Enable blk-mq page allocation tracking with kmemleak, from Catalin. - Unused prototype removal in blk-mq from Christoph. - Cleanup of the q->blk_trace exchange, using cmpxchg instead of two xchg()'s, from Davidlohr. - A plug flush fix from Jeff. - Also from Jeff, a fix that means we don't have to update shared tag sets at init time unless we do a state change. This cuts down boot times on thousands of devices a lot with scsi/blk-mq. - blk-mq waitqueue barrier fix from Kosuke. - Various fixes from Ming: - Fixes for segment merging and splitting, and checks, for the old core and blk-mq. - Potential blk-mq speedup by marking ctx pending at the end of a plug insertion batch in blk-mq. - direct-io no page dirty on kernel direct reads. - A WRITE_SYNC fix for mpage from Roman" * 'for-4.4/core' of git://git.kernel.dk/linux-block: blk-mq: avoid excessive boot delays with large lun counts blktrace: re-write setting q->blk_trace blk-mq: mark ctx as pending at batch in flush plug path blk-mq: fix for trace_block_plug() block: check bio_mergeable() early before merging blk-mq: check bio_mergeable() early before merging block: avoid to merge splitted bio block: setup bi_phys_segments after splitting block: fix plug list flushing for nomerge queues blk-mq: remove unused blk_mq_clone_flush_request prototype blk-mq: fix waitqueue_active without memory barrier in block/blk-mq-tag.c fs: direct-io: don't dirtying pages for ITER_BVEC/ITER_KVEC direct read fs/mpage.c: forgotten WRITE_SYNC in case of data integrity write block: kmemleak: Track the page allocations for struct request
| * | blktrace: re-write setting q->blk_traceDavidlohr Bueso2015-10-301-11/+5
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is really about simplifying the double xchg patterns into a single cmpxchg, with the same logic. Other than the immediate cleanup, there are some subtleties this change deals with: (i) While the load of the old bt is fully ordered wrt everything, ie: old_bt = xchg(&q->blk_trace, bt); [barrier] if (old_bt) (void) xchg(&q->blk_trace, old_bt); [barrier] blk_trace could still be changed between the xchg and the old_bt load. Note that this description is merely theoretical and afaict very small, but doing everything in a single context with cmpxchg closes this potential race. (ii) Ordering guarantees are obviously kept with cmpxchg. (iii) Gets rid of the hacky-by-nature (void)xchg pattern. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> eviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds2015-11-041-2/+53
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking updates from David Miller: Changes of note: 1) Allow to schedule ICMP packets in IPVS, from Alex Gartrell. 2) Provide FIB table ID in ipv4 route dumps just as ipv6 does, from David Ahern. 3) Allow the user to ask for the statistics to be filtered out of ipv4/ipv6 address netlink dumps. From Sowmini Varadhan. 4) More work to pass the network namespace context around deep into various packet path APIs, starting with the netfilter hooks. From Eric W Biederman. 5) Add layer 2 TX/RX checksum offloading to qeth driver, from Thomas Richter. 6) Use usec resolution for SYN/ACK RTTs in TCP, from Yuchung Cheng. 7) Support Very High Throughput in wireless MESH code, from Bob Copeland. 8) Allow setting the ageing_time in switchdev/rocker. From Scott Feldman. 9) Properly autoload L2TP type modules, from Stephen Hemminger. 10) Fix and enable offload features by default in 8139cp driver, from David Woodhouse. 11) Support both ipv4 and ipv6 sockets in a single vxlan device, from Jiri Benc. 12) Fix CWND limiting of thin streams in TCP, from Bendik Rønning Opstad. 13) Fix IPSEC flowcache overflows on large systems, from Steffen Klassert. 14) Convert bridging to track VLANs using rhashtable entries rather than a bitmap. From Nikolay Aleksandrov. 15) Make TCP listener handling completely lockless, this is a major accomplishment. Incoming request sockets now live in the established hash table just like any other socket too. From Eric Dumazet. 15) Provide more bridging attributes to netlink, from Nikolay Aleksandrov. 16) Use hash based algorithm for ipv4 multipath routing, this was very long overdue. From Peter Nørlund. 17) Several y2038 cures, mostly avoiding timespec. From Arnd Bergmann. 18) Allow non-root execution of EBPF programs, from Alexei Starovoitov. 19) Support SO_INCOMING_CPU as setsockopt, from Eric Dumazet. This influences the port binding selection logic used by SO_REUSEPORT. 20) Add ipv6 support to VRF, from David Ahern. 21) Add support for Mellanox Spectrum switch ASIC, from Jiri Pirko. 22) Add rtl8xxxu Realtek wireless driver, from Jes Sorensen. 23) Implement RACK loss recovery in TCP, from Yuchung Cheng. 24) Support multipath routes in MPLS, from Roopa Prabhu. 25) Fix POLLOUT notification for listening sockets in AF_UNIX, from Eric Dumazet. 26) Add new QED Qlogic river, from Yuval Mintz, Manish Chopra, and Sudarsana Kalluru. 27) Don't fetch timestamps on AF_UNIX sockets, from Hannes Frederic Sowa. 28) Support ipv6 geneve tunnels, from John W Linville. 29) Add flood control support to switchdev layer, from Ido Schimmel. 30) Fix CHECKSUM_PARTIAL handling of potentially fragmented frames, from Hannes Frederic Sowa. 31) Support persistent maps and progs in bpf, from Daniel Borkmann. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1790 commits) sh_eth: use DMA barriers switchdev: respect SKIP_EOPNOTSUPP flag in case there is no recursion net: sched: kill dead code in sch_choke.c irda: Delete an unnecessary check before the function call "irlmp_unregister_service" net: dsa: mv88e6xxx: include DSA ports in VLANs net: dsa: mv88e6xxx: disable SA learning for DSA and CPU ports net/core: fix for_each_netdev_feature vlan: Invoke driver vlan hooks only if device is present arcnet/com20020: add LEDS_CLASS dependency bpf, verifier: annotate verbose printer with __printf dp83640: Only wait for timestamps for packets with timestamping enabled. ptp: Change ptp_class to a proper bitmask dp83640: Prune rx timestamp list before reading from it dp83640: Delay scheduled work. dp83640: Include hash in timestamp/packet matching ipv6: fix tunnel error handling net/mlx5e: Fix LSO vlan insertion net/mlx5e: Re-eanble client vlan TX acceleration net/mlx5e: Return error in case mlx5e_set_features() fails net/mlx5e: Don't allow more than max supported channels ...
| * \ Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2015-11-011-0/+11
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| * | | bpf: make tracing helpers gpl onlyAlexei Starovoitov2015-10-261-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | exported perf symbols are GPL only, mark eBPF helper functions used in tracing as GPL only as well. Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | bpf: fix bpf_perf_event_read() helperAlexei Starovoitov2015-10-261-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix safety checks for bpf_perf_event_read(): - only non-inherited events can be added to perf_event_array map (do this check statically at map insertion time) - dynamically check that event is local and !pmu->count Otherwise buggy bpf program can cause kernel splat. Also fix error path after perf_event_attrs() and remove redundant 'extern'. Fixes: 35578d798400 ("bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | bpf: introduce bpf_perf_event_output() helperAlexei Starovoitov2015-10-221-0/+46
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This helper is used to send raw data from eBPF program into special PERF_TYPE_SOFTWARE/PERF_COUNT_SW_BPF_OUTPUT perf_event. User space needs to perf_event_open() it (either for one or all cpus) and store FD into perf_event_array (similar to bpf_perf_event_read() helper) before eBPF program can send data into it. Today the programs triggered by kprobe collect the data and either store it into the maps or print it via bpf_trace_printk() where latter is the debug facility and not suitable to stream the data. This new helper replaces such bpf_trace_printk() usage and allows programs to have dedicated channel into user space for post-processing of the raw data collected. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | | Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2015-11-033-3/+4
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler changes from Ingo Molnar: "The main changes in this cycle were: - sched/fair load tracking fixes and cleanups (Byungchul Park) - Make load tracking frequency scale invariant (Dietmar Eggemann) - sched/deadline updates (Juri Lelli) - stop machine fixes, cleanups and enhancements for bugs triggered by CPU hotplug stress testing (Oleg Nesterov) - scheduler preemption code rework: remove PREEMPT_ACTIVE and related cleanups (Peter Zijlstra) - Rework the sched_info::run_delay code to fix races (Peter Zijlstra) - Optimize per entity utilization tracking (Peter Zijlstra) - ... misc other fixes, cleanups and smaller updates" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits) sched: Don't scan all-offline ->cpus_allowed twice if !CONFIG_CPUSETS sched: Move cpu_active() tests from stop_two_cpus() into migrate_swap_stop() sched: Start stopper early stop_machine: Kill cpu_stop_threads->setup() and cpu_stop_unpark() stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark() stop_machine: Change cpu_stop_queue_two_works() to rely on stopper->enabled stop_machine: Introduce __cpu_stop_queue_work() and cpu_stop_queue_two_works() stop_machine: Ensure that a queued callback will be called before cpu_stop_park() sched/x86: Fix typo in __switch_to() comments sched/core: Remove a parameter in the migrate_task_rq() function sched/core: Drop unlikely behind BUG_ON() sched/core: Fix task and run queue sched_info::run_delay inconsistencies sched/numa: Fix task_tick_fair() from disabling numa_balancing sched/core: Add preempt_count invariant check sched/core: More notrace annotations sched/core: Kill PREEMPT_ACTIVE sched/core, sched/x86: Kill thread_info::saved_preempt_count sched/core: Simplify preempt_count tests sched/core: Robustify preemption leak checks sched/core: Stop setting PREEMPT_ACTIVE ...
| * | sched/core: Fix trace_sched_switch()Peter Zijlstra2015-10-063-3/+4
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | __trace_sched_switch_state() is the last remaining PREEMPT_ACTIVE user, move trace_sched_switch() from prepare_task_switch() to __schedule() and propagate the @preempt argument. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | tracing: Do not allow stack_tracer to record stack in NMISteven Rostedt (Red Hat)2015-10-201-0/+4
| | | | | | | | | | | | | | | | | | | | | | The code in stack tracer should not be executed within an NMI as it grabs spinlocks and stack tracing an NMI gives the possibility of causing a deadlock. Although this is safe on x86_64, because it does not perform stack traces when the task struct stack is not in use (interrupts and NMIs), it may be an issue for NMIs on i386 and other archs that use the same stack as the NMI. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | tracing: Have stack tracer force RCU to be watchingSteven Rostedt (Red Hat)2015-10-201-0/+7
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The stack tracer was triggering the WARN_ON() in module.c: static void module_assert_mutex_or_preempt(void) { #ifdef CONFIG_LOCKDEP if (unlikely(!debug_locks)) return; WARN_ON(!rcu_read_lock_sched_held() && !lockdep_is_held(&module_mutex)); #endif } The reason is that the stack tracer traces all function calls, and some of those calls happen while exiting or entering user space and idle. Some of these functions are called after RCU had already stopped watching, as RCU does not watch userspace or idle CPUs. If a max stack is hit, then the save_stack_trace() is called, which will check module addresses and call module_assert_mutex_or_preempt(), and then trigger the warning. Sad part is, the warning itself will also do a stack trace and tigger the same warning. That probably should be fixed. The warning was added by 0be964be0d45 "module: Sanitize RCU usage and locking" but this bug has probably been around longer. But it's unlikely to cause much harm, but the new warning causes the system to lock up. Cc: stable@vger.kernel.org # 4.2+ Cc: Peter Zijlstra <peterz@infradead.org> Cc:"Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge tag 'trace-v4.3' of ↵Linus Torvalds2015-09-088-416/+516
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing update from Steven Rostedt: "Mostly this is just clean ups and micro optimizations. The changes with more meat are: - Allowing the trace event filters to filter on CPU number and process ids - Two new markers for trace output latency were added (10 and 100 msec latencies) - Have tracing_thresh filter function profiling time I also worked on modifying the ring buffer code for some future work, and moved the adding of the timestamp around. One of my changes caused a regression, and since other changes were built on top of it and already tested, I had to operate a revert of that change. Instead of rebasing, this change set has the code that caused a regression as well as the code to revert that change without touching the other changes that were made on top of it" * tag 'trace-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Revert "ring-buffer: Get timestamp after event is allocated" tracing: Don't make assumptions about length of string on task rename tracing: Allow triggers to filter for CPU ids and process names ftrace: Format MCOUNT_ADDR address as type unsigned long tracing: Introduce two additional marks for delay ftrace: Fix function_graph duration spacing with 7-digits ftrace: add tracing_thresh to function profile tracing: Clean up stack tracing and fix fentry updates ring-buffer: Reorganize function locations ring-buffer: Make sure event has enough room for extend and padding ring-buffer: Get timestamp after event is allocated ring-buffer: Move the adding of the extended timestamp out of line ring-buffer: Add event descriptor to simplify passing data ftrace: correct the counter increment for trace_buffer data tracing: Fix for non-continuous cpu ids tracing: Prefer kcalloc over kzalloc with multiply
| * ring-buffer: Revert "ring-buffer: Get timestamp after event is allocated"Steven Rostedt (Red Hat)2015-09-031-106/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit a4543a2fa9ef31 "ring-buffer: Get timestamp after event is allocated" is needed for some future work. But after adding it, there is a race somewhere that causes the saved timestamp to have a slight shift, and get ahead of the actual timestamp and make it look like time goes backwards. I'm still looking into why this happens, but in the mean time, this is holding up other work to get in. I'm reverting the change for now (which makes the problem go away), and will add it back after I know what is wrong and fix it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Allow triggers to filter for CPU ids and process namesDaniel Wagner2015-08-112-2/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By extending the filter rules by more generic fields we can write triggers filters like echo 'stacktrace if cpu == 1' > \ /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger or echo 'stacktrace if comm == sshd' > \ /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger CPU and COMM are not part of struct trace_entry. We could add the two new fields to ftrace_common_field list and fix up all depending sides. But that looks pretty ugly. Another thing I would like to avoid that the 'format' file contents changes. All this can be avoided by introducing another list which contains non field members of struct trace_entry. Link: http://lkml.kernel.org/r/1439210146-24707-1-git-send-email-daniel.wagner@bmw-carit.de Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Introduce two additional marks for delayJungseok Lee2015-07-201-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A fine granulity support for delay would be very useful when profiling VM logics, such as page allocation including page reclaim and memory compaction with function graph. Thus, this patch adds two additional marks with two changes. - An equal sign in mark selection function is removed to align code behavior with comments and documentation. - The function graph example related to delay in ftrace.txt is updated to cover all supported marks. Link: http://lkml.kernel.org/r/1436626300-1679-3-git-send-email-jungseoklee85@gmail.com Cc: Byungchul Park <byungchul.park@lge.com> Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Fix function_graph duration spacing with 7-digitsSteven Rostedt (Red Hat)2015-07-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jungseok Lee noticed the following: Currently, row's width of 7-digit duration numbers not aligned with other cases like the following example. 3) $ 3999884 us | } 3) | finish_task_switch() { 3) 0.365 us | _raw_spin_unlock_irq(); 3) 3.333 us | } 3) $ 3999976 us | } 3) $ 3999979 us | } /* schedule */ As adding a single white space in case of 7-digit numbers, the format could be unified easily as follows. 3) $ 2237472 us | } 3) | finish_task_switch() { 3) 0.364 us | _raw_spin_unlock_irq(); 3) 3.125 us | } 3) $ 2237556 us | } 3) $ 2237559 us | } /* schedule */ Instead of making a special case for 7-digit numbers, the logic of the len and the space loop is slightly modified to make the two cases have the same format. Link: http://lkml.kernel.org/r/1436626300-1679-2-git-send-email-jungseoklee85@gmail.com Reported-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: add tracing_thresh to function profileUmesh Tiwari2015-07-201-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | This patch extends tracing_thresh functionality to function profile tracer. If tracing_thresh is set, print those entries only, whose average is > tracing thresh. Link: http://lkml.kernel.org/r/1434972488-8571-1-git-send-email-umesh.t@samsung.com Signed-off-by: Umesh Tiwari <umesh.t@samsung.com> [ Removed unnecessary 'moved' comment ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Clean up stack tracing and fix fentry updatesSteven Rostedt (Red Hat)2015-07-201-45/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Akashi Takahiro was porting the stack tracer to arm64 and found some issues with it. One was that it repeats the top function, due to the stack frame added by the mcount caller and added by itself. This was added when fentry came in, and before fentry created its own stack frame. But x86's fentry now creates its own stack frame, and there's no need to insert the function again. This also cleans up the code a bit, where it doesn't need to do something special for fentry, and doesn't include insertion of a duplicate entry for the called function being traced. Link: http://lkml.kernel.org/r/55A646EE.6030402@linaro.org Some-suggestions-by: Jungseok Lee <jungseoklee85@gmail.com> Some-suggestions-by: Mark Rutland <mark.rutland@arm.com> Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Reorganize function locationsSteven Rostedt (Red Hat)2015-07-201-411/+403
| | | | | | | | | | | | | | | | | | Functions in ring-buffer.c have gotten interleaved between different use cases. Move the functions around to get like functions closer together. This may or may not help gcc keep cache locality, but it makes it a little easier to work with the code. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Make sure event has enough room for extend and paddingSteven Rostedt (Red Hat)2015-07-201-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | Now that events only add time extends after it is committed, in case an event comes in before it can discard the allocated event, the time extend needs to be stored within the event. If the event is bigger than then size needed for the time extend, padding must be added. The minimum padding size is 8 bytes. Thus if the event is 12 bytes (size of time extend + 4), there will not be enough room to add both the time extend and padding. Make sure all events are either 8 bytes or 16 or more bytes. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Get timestamp after event is allocatedSteven Rostedt (Red Hat)2015-07-201-47/+114
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the capturing of the timestamp to after an event is allocated. If the event is not a commit (where it is an event that preempted another event), then no timestamp is needed, because the delta of nested events is always zero. If the event starts on a new page, no delta needs to be calculated as the full timestamp will be added to the page header, and the event will have a delta of zero. Now if the event requires a time extend (the delta does not fit in the 27 bit delta slot in the header), then the event is discarded, the length is extended to hold the TIME_EXTEND event that allows for a 59 bit delta, and the commit is tried again. If the event can't be discarded (another event came in after it), then the TIME_EXTEND is added directly to the allocated event and the rest of the event is given padding. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Move the adding of the extended timestamp out of lineSteven Rostedt (Red Hat)2015-07-201-16/+25
| | | | | | | | | | | | | | | | | | | | | | Requiring a extended time stamp is an uncommon occurrence, and it is best to do it out of line when needed. Add a noinline function that handles the extended timestamp and have it called with an unlikely to completely move it out of the fast path. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Add event descriptor to simplify passing dataSteven Rostedt (Red Hat)2015-07-201-39/+52
| | | | | | | | | | | | | | | | Add rb_event_info descriptor to pass event info to functions a bit easier than using a bunch of parameters. This will also allow for changing the code around a bit to find better fast paths. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: correct the counter increment for trace_buffer dataUmesh Tiwari2015-07-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | In ftrace_dump, for disabling buffer, iter.tr->trace_buffer.data is used. But for enabling, iter.trace_buffer->data is used. Even though, both point to same buffer, for readability, same convention should be used. Link: http://lkml.kernel.org/r/1434972306-20043-1-git-send-email-umesh.t@samsung.com Signed-off-by: Umesh Tiwari <umesh.t@samsung.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Fix for non-continuous cpu idsGil Fruchter2015-07-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently exception occures due to access beyond buffer_iter range while using index of cpu bigger than num_possible_cpus(). Below there is an example for such exception when we use cpus 0,1,16,17. In order to fix buffer allocation size for non-continuous cpu ids we allocate according to the max cpu id and not according to the amount of possible cpus. Example: $ cat /sys/kernel/debug/tracing/per_cpu/cpu1/trace Path: /bin/busybox CPU: 0 PID: 82 Comm: cat Not tainted 4.0.0 #29 task: 80734c80 ti: 80012000 task.ti: 80012000 [ECR ]: 0x00220100 => Invalid Read @ 0x00000000 by insn @ 0x800abafc [EFA ]: 0x00000000 [BLINK ]: ring_buffer_read_finish+0x24/0x64 [ERET ]: rb_check_pages+0x20/0x188 [STAT32]: 0x00001a00 : BTA: 0x800abafc SP: 0x80013f0c FP: 0x57719cf8 LPS: 0x200036b4 LPE: 0x200036b8 LPC: 0x00000000 r00: 0x8002aca0 r01: 0x00001606 r02: 0x00000000 r03: 0x00000001 r04: 0x00000000 r05: 0x804b4954 r06: 0x00030003 r07: 0x8002a260 r08: 0x00000286 r09: 0x00080002 r10: 0x00001006 r11: 0x807351a4 r12: 0x00000001 Stack Trace: rb_check_pages+0x20/0x188 ring_buffer_read_finish+0x24/0x64 tracing_release+0x4e/0x170 __fput+0x62/0x158 task_work_run+0xa2/0xd4 do_notify_resume+0x52/0x7c resume_user_mode_begin+0xdc/0xe0 Link: http://lkml.kernel.org/r/1433835155-6894-3-git-send-email-gilf@ezchip.com Signed-off-by: Noam Camus <noamc@ezchip.com> Signed-off-by: Gil Fruchter <gilf@ezchip.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Prefer kcalloc over kzalloc with multiplyGil Fruchter2015-07-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | Use kcalloc for allocating an array instead of kzalloc with multiply, as that is what kcalloc is used for. Found with checkpatch. Link: http://lkml.kernel.org/r/1433835155-6894-2-git-send-email-gilf@ezchip.com Signed-off-by: Gil Fruchter <gilf@ezchip.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds2015-09-032-18/+65
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking updates from David Miller: "Another merge window, another set of networking changes. I've heard rumblings that the lightweight tunnels infrastructure has been voted networking change of the year. But what do I know? 1) Add conntrack support to openvswitch, from Joe Stringer. 2) Initial support for VRF (Virtual Routing and Forwarding), which allows the segmentation of routing paths without using multiple devices. There are some semantic kinks to work out still, but this is a reasonably strong foundation. From David Ahern. 3) Remove spinlock fro act_bpf fast path, from Alexei Starovoitov. 4) Ignore route nexthops with a link down state in ipv6, just like ipv4. From Andy Gospodarek. 5) Remove spinlock from fast path of act_gact and act_mirred, from Eric Dumazet. 6) Document the DSA layer, from Florian Fainelli. 7) Add netconsole support to bcmgenet, systemport, and DSA. Also from Florian Fainelli. 8) Add Mellanox Switch Driver and core infrastructure, from Jiri Pirko. 9) Add support for "light weight tunnels", which allow for encapsulation and decapsulation without bearing the overhead of a full blown netdevice. From Thomas Graf, Jiri Benc, and a cast of others. 10) Add Identifier Locator Addressing support for ipv6, from Tom Herbert. 11) Support fragmented SKBs in iwlwifi, from Johannes Berg. 12) Allow perf PMUs to be accessed from eBPF programs, from Kaixu Xia. 13) Add BQL support to 3c59x driver, from Loganaden Velvindron. 14) Stop using a zero TX queue length to mean that a device shouldn't have a qdisc attached, use an explicit flag instead. From Phil Sutter. 15) Use generic geneve netdevice infrastructure in openvswitch, from Pravin B Shelar. 16) Add infrastructure to avoid re-forwarding a packet in software that was already forwarded by a hardware switch. From Scott Feldman. 17) Allow AF_PACKET fanout function to be implemented in a bpf program, from Willem de Bruijn" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1458 commits) netfilter: nf_conntrack: make nf_ct_zone_dflt built-in netfilter: nf_dup{4, 6}: fix build error when nf_conntrack disabled net: fec: clear receive interrupts before processing a packet ipv6: fix exthdrs offload registration in out_rt path xen-netback: add support for multicast control bgmac: Update fixed_phy_register() sock, diag: fix panic in sock_diag_put_filterinfo flow_dissector: Use 'const' where possible. flow_dissector: Fix function argument ordering dependency ixgbe: Resolve "initialized field overwritten" warnings ixgbe: Remove bimodal SR-IOV disabling ixgbe: Add support for reporting 2.5G link speed ixgbe: fix bounds checking in ixgbe_setup_tc for 82598 ixgbe: support for ethtool set_rxfh ixgbe: Avoid needless PHY access on copper phys ixgbe: cleanup to use cached mask value ixgbe: Remove second instance of lan_id variable ixgbe: use kzalloc for allocating one thing flow: Move __get_hash_from_flowi{4,6} into flow_dissector.c ixgbe: Remove unused PCI bus types ...
| * | bpf: add support for %s specifier to bpf_trace_printk()Alexei Starovoitov2015-08-281-2/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | %s specifier makes bpf program and kernel debugging easier. To make sure that trace_printk won't crash the unsafe string is copied into stack and unsafe pointer is substituted. The following C program: #include <linux/fs.h> int foo(struct pt_regs *ctx, struct filename *filename) { void *name = 0; bpf_probe_read(&name, sizeof(name), &filename->name); bpf_trace_printk("executed %s\n", name); return 0; } when attached to kprobe do_execve() will produce output in /sys/kernel/debug/tracing/trace_pipe : make-13492 [002] d..1 3250.997277: : executed /bin/sh sh-13493 [004] d..1 3250.998716: : executed /usr/bin/gcc gcc-13494 [002] d..1 3250.999822: : executed /usr/lib/gcc/x86_64-linux-gnu/4.7/cc1 gcc-13495 [002] d..1 3251.006731: : executed /usr/bin/as gcc-13496 [002] d..1 3251.011831: : executed /usr/lib/gcc/x86_64-linux-gnu/4.7/collect2 collect2-13497 [000] d..1 3251.012941: : executed /usr/bin/ld Suggested-by: Brendan Gregg <brendan.d.gregg@gmail.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | lib: introduce strncpy_from_unsafe()Alexei Starovoitov2015-08-281-16/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | generalize FETCH_FUNC_NAME(memory, string) into strncpy_from_unsafe() and fix sparse warnings that were present in original implementation. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | bpf: Implement function bpf_perf_event_read() that get the selected hardware ↵Kaixu Xia2015-08-091-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PMU conuter According to the perf_event_map_fd and index, the function bpf_perf_event_read() can convert the corresponding map value to the pointer to struct perf_event and return the Hardware PMU counter value. Signed-off-by: Kaixu Xia <xiakaixu@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | | Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-blockLinus Torvalds2015-09-021-7/+3
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull core block updates from Jens Axboe: "This first core part of the block IO changes contains: - Cleanup of the bio IO error signaling from Christoph. We used to rely on the uptodate bit and passing around of an error, now we store the error in the bio itself. - Improvement of the above from myself, by shrinking the bio size down again to fit in two cachelines on x86-64. - Revert of the max_hw_sectors cap removal from a revision again, from Jeff Moyer. This caused performance regressions in various tests. Reinstate the limit, bump it to a more reasonable size instead. - Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me. Most devices have huge trim limits, which can cause nasty latencies when deleting files. Enable the admin to configure the size down. We will look into having a more sane default instead of UINT_MAX sectors. - Improvement of the SGP gaps logic from Keith Busch. - Enable the block core to handle arbitrarily sized bios, which enables a nice simplification of bio_add_page() (which is an IO hot path). From Kent. - Improvements to the partition io stats accounting, making it faster. From Ming Lei. - Also from Ming Lei, a basic fixup for overflow of the sysfs pending file in blk-mq, as well as a fix for a blk-mq timeout race condition. - Ming Lin has been carrying Kents above mentioned patches forward for a while, and testing them. Ming also did a few fixes around that. - Sasha Levin found and fixed a use-after-free problem introduced by the bio->bi_error changes from Christoph. - Small blk cgroup cleanup from Viresh Kumar" * 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits) blk: Fix bio_io_vec index when checking bvec gaps block: Replace SG_GAPS with new queue limits mask block: bump BLK_DEF_MAX_SECTORS to 2560 Revert "block: remove artifical max_hw_sectors cap" blk-mq: fix race between timeout and freeing request blk-mq: fix buffer overflow when reading sysfs file of 'pending' Documentation: update notes in biovecs about arbitrarily sized bios block: remove bio_get_nr_vecs() fs: use helper bio_add_page() instead of open coding on bi_io_vec block: kill merge_bvec_fn() completely md/raid5: get rid of bio_fits_rdev() md/raid5: split bio for chunk_aligned_read block: remove split code in blkdev_issue_{discard,write_same} btrfs: remove bio splitting and merge_bvec_fn() calls bcache: remove driver private bio splitting code block: simplify bio_add_page() block: make generic_make_request handle arbitrarily sized bios blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL) block: don't access bio->bi_error after bio_put() block: shrink struct bio down to 2 cache lines again ...
| * | | block: add a bi_error field to struct bioChristoph Hellwig2015-07-291-7/+3
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>