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2015-02-13Reset to 3.12.37Scott Wood
2014-05-14perf: Make swevent hrtimer run in irq instead of softirqYong Zhang
Otherwise we get a deadlock like below: [ 1044.042749] BUG: scheduling while atomic: ksoftirqd/21/141/0x00010003 [ 1044.042752] INFO: lockdep is turned off. [ 1044.042754] Modules linked in: [ 1044.042757] Pid: 141, comm: ksoftirqd/21 Tainted: G W 3.4.0-rc2-rt3-23676-ga723175-dirty #29 [ 1044.042759] Call Trace: [ 1044.042761] <IRQ> [<ffffffff8107d8e5>] __schedule_bug+0x65/0x80 [ 1044.042770] [<ffffffff8168978c>] __schedule+0x83c/0xa70 [ 1044.042775] [<ffffffff8106bdd2>] ? prepare_to_wait+0x32/0xb0 [ 1044.042779] [<ffffffff81689a5e>] schedule+0x2e/0xa0 [ 1044.042782] [<ffffffff81071ebd>] hrtimer_wait_for_timer+0x6d/0xb0 [ 1044.042786] [<ffffffff8106bb30>] ? wake_up_bit+0x40/0x40 [ 1044.042790] [<ffffffff81071f20>] hrtimer_cancel+0x20/0x40 [ 1044.042794] [<ffffffff8111da0c>] perf_swevent_cancel_hrtimer+0x3c/0x50 [ 1044.042798] [<ffffffff8111da31>] task_clock_event_stop+0x11/0x40 [ 1044.042802] [<ffffffff8111da6e>] task_clock_event_del+0xe/0x10 [ 1044.042805] [<ffffffff8111c568>] event_sched_out+0x118/0x1d0 [ 1044.042809] [<ffffffff8111c649>] group_sched_out+0x29/0x90 [ 1044.042813] [<ffffffff8111ed7e>] __perf_event_disable+0x18e/0x200 [ 1044.042817] [<ffffffff8111c343>] remote_function+0x63/0x70 [ 1044.042821] [<ffffffff810b0aae>] generic_smp_call_function_single_interrupt+0xce/0x120 [ 1044.042826] [<ffffffff81022bc7>] smp_call_function_single_interrupt+0x27/0x40 [ 1044.042831] [<ffffffff8168d50c>] call_function_single_interrupt+0x6c/0x80 [ 1044.042833] <EOI> [<ffffffff811275b0>] ? perf_event_overflow+0x20/0x20 [ 1044.042840] [<ffffffff8168b970>] ? _raw_spin_unlock_irq+0x30/0x70 [ 1044.042844] [<ffffffff8168b976>] ? _raw_spin_unlock_irq+0x36/0x70 [ 1044.042848] [<ffffffff810702e2>] run_hrtimer_softirq+0xc2/0x200 [ 1044.042853] [<ffffffff811275b0>] ? perf_event_overflow+0x20/0x20 [ 1044.042857] [<ffffffff81045265>] __do_softirq_common+0xf5/0x3a0 [ 1044.042862] [<ffffffff81045c3d>] __thread_do_softirq+0x15d/0x200 [ 1044.042865] [<ffffffff81045dda>] run_ksoftirqd+0xfa/0x210 [ 1044.042869] [<ffffffff81045ce0>] ? __thread_do_softirq+0x200/0x200 [ 1044.042873] [<ffffffff81045ce0>] ? __thread_do_softirq+0x200/0x200 [ 1044.042877] [<ffffffff8106b596>] kthread+0xb6/0xc0 [ 1044.042881] [<ffffffff8168b97b>] ? _raw_spin_unlock_irq+0x3b/0x70 [ 1044.042886] [<ffffffff8168d994>] kernel_thread_helper+0x4/0x10 [ 1044.042889] [<ffffffff8107d98c>] ? finish_task_switch+0x8c/0x110 [ 1044.042894] [<ffffffff8168b97b>] ? _raw_spin_unlock_irq+0x3b/0x70 [ 1044.042897] [<ffffffff8168bd5d>] ? retint_restore_args+0xe/0xe [ 1044.042900] [<ffffffff8106b4e0>] ? kthreadd+0x1e0/0x1e0 [ 1044.042902] [<ffffffff8168d990>] ? gs_change+0xb/0xb Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1341476476-5666-1-git-send-email-yong.zhang0@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-14Reset to 3.12.19Scott Wood
2014-04-10perf: Make swevent hrtimer run in irq instead of softirqYong Zhang
Otherwise we get a deadlock like below: [ 1044.042749] BUG: scheduling while atomic: ksoftirqd/21/141/0x00010003 [ 1044.042752] INFO: lockdep is turned off. [ 1044.042754] Modules linked in: [ 1044.042757] Pid: 141, comm: ksoftirqd/21 Tainted: G W 3.4.0-rc2-rt3-23676-ga723175-dirty #29 [ 1044.042759] Call Trace: [ 1044.042761] <IRQ> [<ffffffff8107d8e5>] __schedule_bug+0x65/0x80 [ 1044.042770] [<ffffffff8168978c>] __schedule+0x83c/0xa70 [ 1044.042775] [<ffffffff8106bdd2>] ? prepare_to_wait+0x32/0xb0 [ 1044.042779] [<ffffffff81689a5e>] schedule+0x2e/0xa0 [ 1044.042782] [<ffffffff81071ebd>] hrtimer_wait_for_timer+0x6d/0xb0 [ 1044.042786] [<ffffffff8106bb30>] ? wake_up_bit+0x40/0x40 [ 1044.042790] [<ffffffff81071f20>] hrtimer_cancel+0x20/0x40 [ 1044.042794] [<ffffffff8111da0c>] perf_swevent_cancel_hrtimer+0x3c/0x50 [ 1044.042798] [<ffffffff8111da31>] task_clock_event_stop+0x11/0x40 [ 1044.042802] [<ffffffff8111da6e>] task_clock_event_del+0xe/0x10 [ 1044.042805] [<ffffffff8111c568>] event_sched_out+0x118/0x1d0 [ 1044.042809] [<ffffffff8111c649>] group_sched_out+0x29/0x90 [ 1044.042813] [<ffffffff8111ed7e>] __perf_event_disable+0x18e/0x200 [ 1044.042817] [<ffffffff8111c343>] remote_function+0x63/0x70 [ 1044.042821] [<ffffffff810b0aae>] generic_smp_call_function_single_interrupt+0xce/0x120 [ 1044.042826] [<ffffffff81022bc7>] smp_call_function_single_interrupt+0x27/0x40 [ 1044.042831] [<ffffffff8168d50c>] call_function_single_interrupt+0x6c/0x80 [ 1044.042833] <EOI> [<ffffffff811275b0>] ? perf_event_overflow+0x20/0x20 [ 1044.042840] [<ffffffff8168b970>] ? _raw_spin_unlock_irq+0x30/0x70 [ 1044.042844] [<ffffffff8168b976>] ? _raw_spin_unlock_irq+0x36/0x70 [ 1044.042848] [<ffffffff810702e2>] run_hrtimer_softirq+0xc2/0x200 [ 1044.042853] [<ffffffff811275b0>] ? perf_event_overflow+0x20/0x20 [ 1044.042857] [<ffffffff81045265>] __do_softirq_common+0xf5/0x3a0 [ 1044.042862] [<ffffffff81045c3d>] __thread_do_softirq+0x15d/0x200 [ 1044.042865] [<ffffffff81045dda>] run_ksoftirqd+0xfa/0x210 [ 1044.042869] [<ffffffff81045ce0>] ? __thread_do_softirq+0x200/0x200 [ 1044.042873] [<ffffffff81045ce0>] ? __thread_do_softirq+0x200/0x200 [ 1044.042877] [<ffffffff8106b596>] kthread+0xb6/0xc0 [ 1044.042881] [<ffffffff8168b97b>] ? _raw_spin_unlock_irq+0x3b/0x70 [ 1044.042886] [<ffffffff8168d994>] kernel_thread_helper+0x4/0x10 [ 1044.042889] [<ffffffff8107d98c>] ? finish_task_switch+0x8c/0x110 [ 1044.042894] [<ffffffff8168b97b>] ? _raw_spin_unlock_irq+0x3b/0x70 [ 1044.042897] [<ffffffff8168bd5d>] ? retint_restore_args+0xe/0xe [ 1044.042900] [<ffffffff8106b4e0>] ? kthreadd+0x1e0/0x1e0 [ 1044.042902] [<ffffffff8168d990>] ? gs_change+0xb/0xb Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1341476476-5666-1-git-send-email-yong.zhang0@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-03-05perf: Fix hotplug splatPeter Zijlstra
commit e3703f8cdfcf39c25c4338c3ad8e68891cca3731 upstream. Drew Richardson reported that he could make the kernel go *boom* when hotplugging while having perf events active. It turned out that when you have a group event, the code in __perf_event_exit_context() fails to remove the group siblings from the context. We then proceed with destroying and freeing the event, and when you re-plug the CPU and try and add another event to that CPU, things go *boom* because you've still got dead entries there. Reported-by: Drew Richardson <drew.richardson@arm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/n/tip-k6v5wundvusvcseqj1si0oz0@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-02-26perf: Enforce 1 as lower limit for perf_event_max_sample_rateKnut Petersen
commit 723478c8a471403c53cf144999701f6e0c4bbd11 upstream. /proc/sys/kernel/perf_event_max_sample_rate will accept negative values as well as 0. Negative values are unreasonable, and 0 causes a divide by zero exception in perf_proc_update_handler. This patch enforces a lower limit of 1. Signed-off-by: Knut Petersen <Knut_Petersen@t-online.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/5242DB0C.4070005@t-online.de Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2013-10-29perf: Fix perf ring buffer memory orderingPeter Zijlstra
The PPC64 people noticed a missing memory barrier and crufty old comments in the perf ring buffer code. So update all the comments and add the missing barrier. When the architecture implements local_t using atomic_long_t there will be double barriers issued; but short of introducing more conditional barrier primitives this is the best we can do. Reported-by: Victor Kaplansky <victork@il.ibm.com> Tested-by: Victor Kaplansky <victork@il.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: michael@ellerman.id.au Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: anton@samba.org Cc: benh@kernel.crashing.org Link: http://lkml.kernel.org/r/20131025173749.GG19466@laptop.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-17perf: Disable PERF_RECORD_MMAP2 supportStephane Eranian
For now, we disable the extended MMAP record support (MMAP2). We have identified cases where it would not report the correct mapping information, clone(VM_CLONE) but with separate pids. We will revisit the support once we find a solution for this case. The patch changes the kernel to return EINVAL if attr->mmap2 is set. The patch also modifies the perf tool to use regular PERF_RECORD_MMAP for synthetic events and it also prevents the tool from requesting attr->mmap2 mode because the kernel would reject it. The support will be revisited once the kenrel interface is updated. In V2, we reduce the patch to the strict minimum. In V3, we avoid calling perf_event_open() with mmap2 set because we know it will fail and require fallback retry. Signed-off-by: Stephane Eranian <eranian@google.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20131017173215.GA8820@quad Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-10-04perf: Fix perf_pmu_migrate_contextPeter Zijlstra
While auditing the list_entry usage due to a trinity bug I found that perf_pmu_migrate_context violates the rules for perf_event::event_entry. The problem is that perf_event::event_entry is a RCU list element, and hence we must wait for a full RCU grace period before re-using the element after deletion. Therefore the usage in perf_pmu_migrate_context() which re-uses the entry immediately is broken. For now introduce another list_head into perf_event for this specific usage. This doesn't actually fix the trinity report because that never goes through this code. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-mkj72lxagw1z8fvjm648iznw@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-20perf: Fix capabilities bitfield compatibility in 'struct perf_event_mmap_page'Peter Zijlstra
Solve the problems around the broken definition of perf_event_mmap_page:: cap_usr_time and cap_usr_rdpmc fields which used to overlap, partially fixed by: 860f085b74e9 ("perf: Fix broken union in 'struct perf_event_mmap_page'") The problem with the fix (merged in v3.12-rc1 and not yet released officially), noticed by Vince Weaver is that the new behavior is not detectable by new user-space, and that due to the reuse of the field names it's easy to mis-compile a binary if old headers are used on a new kernel or new headers are used on an old kernel. To solve all that make this change explicit, detectable and self-contained, by iterating the ABI the following way: - Always clear bit 0, and rename it to usrpage->cap_bit0, to at least not confuse old user-space binaries. RDPMC will be marked as unavailable to old binaries but that's within the ABI, this is a capability bit. - Rename bit 1 to ->cap_bit0_is_deprecated and always set it to 1, so new libraries can reliably detect that bit 0 is deprecated and perma-zero without having to check the kernel version. - Use bits 2, 3, 4 for the newly defined, correct functionality: cap_user_rdpmc : 1, /* The RDPMC instruction can be used to read counts */ cap_user_time : 1, /* The time_* fields are used */ cap_user_time_zero : 1, /* The time_zero field is used */ - Rename all the bitfield names in perf_event.h to be different from the old names, to make sure it's not possible to mis-compile it accidentally with old assumptions. The 'size' field can then be used in the future to add new fields and it will act as a natural ABI version indicator as well. Also adjust tools/perf/ userspace for the new definitions, noticed by Adrian Hunter. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Also-Fixed-by: Adrian Hunter <adrian.hunter@intel.com> Link: http://lkml.kernel.org/n/tip-zr03yxjrpXesOzzupszqglbv@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-12uprobes: Fix utask->depth accounting in handle_trampoline()Oleg Nesterov
Currently utask->depth is simply the number of allocated/pending return_instance's in uprobe_task->return_instances list. handle_trampoline() should decrement this counter every time we handle/free an instance, but due to typo it does this only if ->chained == T. This means that in the likely case this counter is never decremented and the probed task can't report more than MAX_URETPROBE_DEPTH events. Reported-by: Mikhail Kulemin <Mikhail.Kulemin@ru.ibm.com> Reported-by: Hemant Kumar Shaw <hkshaw@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Anton Arapov <anton@redhat.com> Cc: masami.hiramatsu.pt@hitachi.com Cc: srikar@linux.vnet.ibm.com Cc: systemtap@sourceware.org Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20130911154726.GA8093@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-11perf: Fix up MMAP2 buffer space reservationArnaldo Carvalho de Melo
The ino_generation field was added in the PERF_RECORD_MMAP2 record in the 13d7a24 cset but no space for it was allocated, corrupting the PERF_FORMAT_{TIME,CPU,TID,etc} area (sample_type/sample_id_all), fix it. Detected with one of the regression tests done by 'perf test': [root@sandy ~]# perf test -v 7 7: Validate PERF_RECORD_* events & perf_sample fields : --- start --- 61315294449606 0 PERF_RECORD_SAMPLE 61315294453161 0 PERF_RECORD_SAMPLE 61315294454441 0 PERF_RECORD_SAMPLE 61315294455709 0 PERF_RECORD_SAMPLE 61315295600899 0 PERF_RECORD_COMM: sleep:6500 27917287430500 342521613 PERF_RECORD_MMAP2 6500/6500: [0x400000(0x7000) @ 0 00:1d 311442 9016]: /usr/bin/sleep MMAP2 going backwards in time, prev=61315295600899, curr=27917287430500 MMAP2 with unexpected cpu, expected 0, got 342521613 MMAP2 with unexpected pid, expected 6500, got 1701606191 MMAP2 with unexpected tid, expected 6500, got 28773 27917287430500 342561333 PERF_RECORD_MMAP2 6500/6500: [0x3b7e000000(0x223000) @ 0 00:1d 309186 9016]: /usr/lib64/ld-2.16.so MMAP2 with unexpected cpu, expected 0, got 342561333 MMAP2 with unexpected pid, expected 6500, got 1932408369 MMAP2 with unexpected tid, expected 6500, got 111 27917287430500 342600095 PERF_RECORD_MMAP2 6500/6500: [0x7fffbd7dc000(0x1000) @ 0x7fffbd7dc000 00:00 0 0]: [vdso] MMAP2 with unexpected cpu, expected 0, got 342600095 MMAP2 with unexpected pid, expected 6500, got 1935963739 MMAP2 with unexpected tid, expected 6500, got 23919 27917287430500 342882834 PERF_RECORD_MMAP2 6500/6500: [0x3b7e400000(0x3b8000) @ 0 00:1d 309187 9016]: /usr/lib64/libc-2.16.so MMAP2 with unexpected cpu, expected 0, got 342882834 MMAP2 with unexpected pid, expected 6500, got 909192754 MMAP2 with unexpected tid, expected 6500, got 7303982 61316297195411 0 PERF_RECORD_EXIT(6500:6500):(6500:6500) ---- end ---- Validate PERF_RECORD_* events & perf_sample fields: FAILED! [root@sandy ~]# After this patch: [root@sandy ~]# perf test 7 7: Validate PERF_RECORD_* events & perf_sample fields : Ok [root@sandy ~]# Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Stephane Eranian <eranian@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-heeuv986b8ha7whqg4o3he7c@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-09-04Merge branches 'perf-urgent-for-linus' and 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf changes from Ingo Molnar: "As a first remark I'd like to point out that the obsolete '-f' (--force) option, which has not done anything for several releases, has been removed from 'perf record' and related utilities. Everyone please update muscle memory accordingly! :-) Main changes on the perf kernel side: - Performance optimizations: . for trace events, by Steve Rostedt. . for time values, by Peter Zijlstra - New hardware support: . for Intel Silvermont (22nm Atom) CPUs, by Zheng Yan . for Intel SNB-EP uncore PMUs, by Zheng Yan - Enhanced hardware support: . for Intel uncore PMUs: add filter support for QPI boxes, by Zheng Yan - Core perf events code enhancements and fixes: . for full-nohz feature handling, by Frederic Weisbecker . for group events, by Jiri Olsa . for call chains, by Frederic Weisbecker . for event stream parsing, by Adrian Hunter - New ABI details: . Add attr->mmap2 attribute, by Stephane Eranian . Add PERF_EVENT_IOC_ID ioctl to return event ID, by Jiri Olsa . Export u64 time_zero on the mmap header page to allow TSC calculation, by Adrian Hunter . Add dummy software event, by Adrian Hunter. . Add a new PERF_SAMPLE_IDENTIFIER to make samples always parseable, by Adrian Hunter. . Make Power7 events available via sysfs, by Runzhen Wang. - Code cleanups and refactorings: . for nohz-full, by Frederic Weisbecker . for group events, by Jiri Olsa - Documentation updates: . for perf_event_type, by Peter Zijlstra Main changes on the perf tooling side (some of these tooling changes utilize the above kernel side changes): - Lots of 'perf trace' enhancements: . Make 'perf trace' command line arguments consistent with 'perf record', by David Ahern. . Allow specifying syscalls a la strace, by Arnaldo Carvalho de Melo. . Add --verbose and -o/--output options, by Arnaldo Carvalho de Melo. . Support ! in -e expressions, to filter a list of syscalls, by Arnaldo Carvalho de Melo. . Arg formatting improvements to allow masking arguments in syscalls such as futex and open, where the some arguments are ignored and thus should not be printed depending on other args, by Arnaldo Carvalho de Melo. . Beautify futex open, openat, open_by_handle_at, lseek and futex syscalls, by Arnaldo Carvalho de Melo. . Add option to analyze events in a file versus live, so that one can do: [root@zoo ~]# perf record -a -e raw_syscalls:* sleep 1 [ perf record: Woken up 0 times to write data ] [ perf record: Captured and wrote 25.150 MB perf.data (~1098836 samples) ] [root@zoo ~]# perf trace -i perf.data -e futex --duration 1 17.799 ( 1.020 ms): 7127 futex(uaddr: 0x7fff3f6c6674, op: 393, val: 1, utime: 0x7fff3f6c6470, ua 113.344 (95.429 ms): 7127 futex(uaddr: 0x7fff3f6c6674, op: 393, val: 1, utime: 0x7fff3f6c6470, uaddr2: 0x7fff3f6c6648, val3: 4294967 133.778 ( 1.042 ms): 18004 futex(uaddr: 0x7fff3f6c6674, op: 393, val: 1, utime: 0x7fff3f6c6470, uaddr2: 0x7fff3f6c6648, val3: 429496 [root@zoo ~]# By David Ahern. . Honor target pid / tid options when analyzing a file, by David Ahern. . Introduce better formatting of syscall arguments, including so far beautifiers for mmap, madvise, syscall return values, by Arnaldo Carvalho de Melo. . Handle HUGEPAGE defines in the mmap beautifier, by David Ahern. - 'perf report/top' enhancements: . Do annotation using /proc/kcore and /proc/kallsyms when available, removing the forced need for a vmlinux file kernel assembly annotation. This also improves this use case because vmlinux has just the initial kernel image, not what is actually in use after various code patchings by things like alternatives. By Adrian Hunter. . Add --ignore-callees=<regex> option to collapse undesired parts of call graphs, by Greg Price. . Simplify symbol filtering by doing it at machine class level, by Adrian Hunter. . Add support for callchains in the gtk UI, by Namhyung Kim. . Add --objdump option to 'perf top', by Sukadev Bhattiprolu. - 'perf kvm' enhancements: . Add option to print only events that exceed a specified time duration, by David Ahern. . Improve stack trace printing, by David Ahern. . Update documentation of the live command, by David Ahern . Add perf kvm stat live mode that combines aspects of 'perf kvm stat' record and report, by David Ahern. . Add option to analyze specific VM in perf kvm stat report, by David Ahern. . Do not require /lib/modules/* on a guest, by Jason Wessel. - 'perf script' enhancements: . Fix symbol offset computation for some dsos, by David Ahern. . Fix named threads support, by David Ahern. . Don't install scripting files files when perl/python support is disabled, by Arnaldo Carvalho de Melo. - 'perf test' enhancements: . Add various improvements and fixes to the "vmlinux matches kallsyms" 'perf test' entry, related to the /proc/kcore annotation feature. By Adrian Hunter. . Add sample parsing test, by Adrian Hunter. . Add test for reading object code, by Adrian Hunter. . Add attr record group sampling test, by Jiri Olsa. . Misc testing infrastructure improvements and other details, by Jiri Olsa. - 'perf list' enhancements: . Skip unsupported hardware events, by Namhyung Kim. . List pmu events, by Andi Kleen. - 'perf diff' enhancements: . Add support for more than two files comparison, by Jiri Olsa. - 'perf sched' enhancements: . Various improvements, including removing reliance on some scheduler tracepoints that provide the same information as the PERF_RECORD_{FORK,EXIT} events. By David Ahern. . Remove odd build stall by moving a large struct initialization from a local variable to a global one, by Namhyung Kim. - 'perf stat' enhancements: . Add --initial-delay option to skip measuring for a defined startup phase, by Andi Kleen. - Generic perf tooling infrastructure/plumbing changes: . Tidy up sample parsing validation, by Adrian Hunter. . Fix up jobserver setup in libtraceevent Makefile. by Arnaldo Carvalho de Melo. . Debug improvements, by Adrian Hunter. . Fix correlation of samples coming after PERF_RECORD_EXIT event, by David Ahern. . Improve robustness of the topology parsing code, by Stephane Eranian. . Add group leader sampling, that allows just one event in a group to sample while the other events have just its values read, by Jiri Olsa. . Add support for a new modifier "D", which requests that the event, or group of events, be pinned to the PMU. By Michael Ellerman. . Support callchain sorting based on addresses, by Andi Kleen . Prep work for multi perf data file storage, by Jiri Olsa. . libtraceevent cleanups, by Namhyung Kim. And lots and lots of other fixes and code reorganizations that did not make it into the list, see the shortlog, diffstat and the Git log for details!" [ Also merge a leftover from the 3.11 cycle ] * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Prevent race in unthrottling code * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (237 commits) perf trace: Tell arg formatters the arg index perf trace: Add beautifier for open's flags arg perf trace: Add beautifier for lseek's whence arg perf tools: Fix symbol offset computation for some dsos perf list: Skip unsupported events perf tests: Add 'keep tracking' test perf tools: Add support for PERF_COUNT_SW_DUMMY perf: Add a dummy software event to keep tracking perf trace: Add beautifier for futex 'operation' parm perf trace: Allow syscall arg formatters to mask args perf: Convert kmalloc_node(...GFP_ZERO...) to kzalloc_node() perf: Export struct perf_branch_entry to userspace perf: Add attr->mmap2 attribute to an event perf/x86: Add Silvermont (22nm Atom) support perf/x86: use INTEL_UEVENT_EXTRA_REG to define MSR_OFFCORE_RSP_X perf trace: Handle missing HUGEPAGE defines perf trace: Honor target pid / tid options when analyzing a file perf trace: Add option to analyze events in a file versus live perf evlist: Add tracepoint lookup by name perf tests: Add a sample parsing test ...
2013-09-04Merge branch 'for-3.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "A lot of activities on the cgroup front. Most changes aren't visible to userland at all at this point and are laying foundation for the planned unified hierarchy. - The biggest change is decoupling the lifetime management of css (cgroup_subsys_state) from that of cgroup's. Because controllers (cpu, memory, block and so on) will need to be dynamically enabled and disabled, css which is the association point between a cgroup and a controller may come and go dynamically across the lifetime of a cgroup. Till now, css's were created when the associated cgroup was created and stayed till the cgroup got destroyed. Assumptions around this tight coupling permeated through cgroup core and controllers. These assumptions are gradually removed, which consists bulk of patches, and css destruction path is completely decoupled from cgroup destruction path. Note that decoupling of creation path is relatively easy on top of these changes and the patchset is pending for the next window. - cgroup has its own event mechanism cgroup.event_control, which is only used by memcg. It is overly complex trying to achieve high flexibility whose benefits seem dubious at best. Going forward, new events will simply generate file modified event and the existing mechanism is being made specific to memcg. This pull request contains prepatory patches for such change. - Various fixes and cleanups" Fixed up conflict in kernel/cgroup.c as per Tejun. * 'for-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (69 commits) cgroup: fix cgroup_css() invocation in css_from_id() cgroup: make cgroup_write_event_control() use css_from_dir() instead of __d_cgrp() cgroup: make cgroup_event hold onto cgroup_subsys_state instead of cgroup cgroup: implement CFTYPE_NO_PREFIX cgroup: make cgroup_css() take cgroup_subsys * instead and allow NULL subsys cgroup: rename cgroup_css_from_dir() to css_from_dir() and update its syntax cgroup: fix cgroup_write_event_control() cgroup: fix subsystem file accesses on the root cgroup cgroup: change cgroup_from_id() to css_from_id() cgroup: use css_get() in cgroup_create() to check CSS_ROOT cpuset: remove an unncessary forward declaration cgroup: RCU protect each cgroup_subsys_state release cgroup: move subsys file removal to kill_css() cgroup: factor out kill_css() cgroup: decouple cgroup_subsys_state destruction from cgroup destruction cgroup: replace cgroup->css_kill_cnt with ->nr_css cgroup: bounce cgroup_subsys_state ref kill confirmation to a work item cgroup: move cgroup->subsys[] assignment to online_css() cgroup: reorganize css init / exit paths cgroup: add __rcu modifier to cgroup->subsys[] ...
2013-09-02perf: Add attr->mmap2 attribute to an eventStephane Eranian
Adds a new PERF_RECORD_MMAP2 record type which is essence an expanded version of PERF_RECORD_MMAP. Used to request mmap records with more information about the mapping, including device major, minor and the inode number and generation for mappings associated with files or shared memory segments. Works for code and data (with attr->mmap_data set). Existing PERF_RECORD_MMAP record is unmodified by this patch. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Link: http://lkml.kernel.org/r/1377079825-19057-2-git-send-email-eranian@google.com [ Added Al to the Cc:. Are the ino, maj/min exports of vma->vm_file OK? ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-02perf: Prevent race in unthrottling codeJiri Olsa
The current throttling code triggers WARN below via following workload (only hit on AMD machine with 48 CPUs): # while [ 1 ]; do perf record perf bench sched messaging; done WARNING: at arch/x86/kernel/cpu/perf_event.c:1054 x86_pmu_start+0xc6/0x100() SNIP Call Trace: <IRQ> [<ffffffff815f62d6>] dump_stack+0x19/0x1b [<ffffffff8105f531>] warn_slowpath_common+0x61/0x80 [<ffffffff8105f60a>] warn_slowpath_null+0x1a/0x20 [<ffffffff810213a6>] x86_pmu_start+0xc6/0x100 [<ffffffff81129dd2>] perf_adjust_freq_unthr_context.part.75+0x182/0x1a0 [<ffffffff8112a058>] perf_event_task_tick+0xc8/0xf0 [<ffffffff81093221>] scheduler_tick+0xd1/0x140 [<ffffffff81070176>] update_process_times+0x66/0x80 [<ffffffff810b9565>] tick_sched_handle.isra.15+0x25/0x60 [<ffffffff810b95e1>] tick_sched_timer+0x41/0x60 [<ffffffff81087c24>] __run_hrtimer+0x74/0x1d0 [<ffffffff810b95a0>] ? tick_sched_handle.isra.15+0x60/0x60 [<ffffffff81088407>] hrtimer_interrupt+0xf7/0x240 [<ffffffff81606829>] smp_apic_timer_interrupt+0x69/0x9c [<ffffffff8160569d>] apic_timer_interrupt+0x6d/0x80 <EOI> [<ffffffff81129f74>] ? __perf_event_task_sched_in+0x184/0x1a0 [<ffffffff814dd937>] ? kfree_skbmem+0x37/0x90 [<ffffffff815f2c47>] ? __slab_free+0x1ac/0x30f [<ffffffff8118143d>] ? kfree+0xfd/0x130 [<ffffffff81181622>] kmem_cache_free+0x1b2/0x1d0 [<ffffffff814dd937>] kfree_skbmem+0x37/0x90 [<ffffffff814e03c4>] consume_skb+0x34/0x80 [<ffffffff8158b057>] unix_stream_recvmsg+0x4e7/0x820 [<ffffffff814d5546>] sock_aio_read.part.7+0x116/0x130 [<ffffffff8112c10c>] ? __perf_sw_event+0x19c/0x1e0 [<ffffffff814d5581>] sock_aio_read+0x21/0x30 [<ffffffff8119a5d0>] do_sync_read+0x80/0xb0 [<ffffffff8119ac85>] vfs_read+0x145/0x170 [<ffffffff8119b699>] SyS_read+0x49/0xa0 [<ffffffff810df516>] ? __audit_syscall_exit+0x1f6/0x2a0 [<ffffffff81604a19>] system_call_fastpath+0x16/0x1b ---[ end trace 622b7e226c4a766a ]--- The reason is a race in perf_event_task_tick() throttling code. The race flow (simplified code): - perf_throttled_count is per cpu variable and is CPU throttling flag, here starting with 0 - perf_throttled_seq is sequence/domain for allowed count of interrupts within the tick, gets increased each tick on single CPU (CPU bounded event): ... workload perf_event_task_tick: | | T0 inc(perf_throttled_seq) | T1 needs_unthr = xchg(perf_throttled_count, 0) == 0 tick gets interrupted: ... event gets throttled under new seq ... T2 last NMI comes, event is throttled - inc(perf_throttled_count) back to tick: | perf_adjust_freq_unthr_context: | | T3 unthrottling is skiped for event (needs_unthr == 0) | T4 event is stop and started via freq adjustment | tick ends ... workload ... no sample is hit for event ... perf_event_task_tick: | | T5 needs_unthr = xchg(perf_throttled_count, 0) != 0 (from T2) | T6 unthrottling is done on event (interrupts == MAX_INTERRUPTS) | event is already started (from T4) -> WARN Fixing this by not checking needs_unthr again and thus check all events for unthrottling. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Reported-by: Jan Stancek <jstancek@redhat.com> Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1377355554-8934-1-git-send-email-jolsa@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-08-29perf: make events stream always parsableAdrian Hunter
The event stream is not always parsable because the format of a sample is dependent on the sample_type of the selected event. When there is more than one selected event and the sample_types are not the same then parsing becomes problematic. A sample can be matched to its selected event using the ID that is allocated when the event is opened. Unfortunately, to get the ID from the sample means first parsing it. This patch adds a new sample format bit PERF_SAMPLE_IDENTIFER that puts the ID at a fixed position so that the ID can be retrieved without parsing the sample. For sample events, that is the first position immediately after the header. For non-sample events, that is the last position. In this respect parsing samples requires that the sample_type and ID values are recorded. For example, perf tools records struct perf_event_attr and the IDs within the perf.data file. Those must be read first before it is possible to parse samples found later in the perf.data file. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1377591794-30553-6-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-08-26cgroup: rename cgroup_css_from_dir() to css_from_dir() and update its syntaxTejun Heo
cgroup_css_from_dir() will grow another user. In preparation, make the following changes. * All css functions are prefixed with just "css_", rename it to css_from_dir(). * Take dentry * instead of file * as dentry is what ultimately identifies a cgroup and file may not always be available. Note that the function now checkes whether @dentry->d_inode is NULL as the caller now may specify a negative dentry. * Make it take cgroup_subsys * instead of integer subsys_id. This simplifies the function and allows specifying no subsystem for cgroup->dummy_css. * Make return section a bit less verbose. This patch doesn't introduce any behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com>
2013-08-16perf: Do not compute time values unnecessarilyPeter Zijlstra
We should not be calling calc_timer_values() for events that do not actually have an mmap()'ed userpage. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20130802191630.GT27162@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-08-16perf: Account freq events globallyFrederic Weisbecker
Freq events may not always be affine to a particular CPU. As such, account_event_cpu() may crash if we account per cpu a freq event that has event->cpu == -1. To solve this, lets account freq events globally. In practice this doesn't change much the picture because perf tools create per-task perf events with one event per CPU by default. Profiling a single CPU is usually a corner case so there is no much point in optimizing things that way. Reported-by: Jiri Olsa <jolsa@redhat.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1375460996-16329-3-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-08-16perf: Roll back callchain buffer refcount under the callchain mutexFrederic Weisbecker
When we fail to allocate the callchain buffers, we roll back the refcount we did and return from get_callchain_buffers(). However we take the refcount and allocate under the callchain lock but the rollback is done outside the lock. As a result, while we roll back, some concurrent callchain user may call get_callchain_buffers(), see the non-zero refcount and give up because the buffers are NULL without itself retrying the allocation. The consequences aren't that bad but that behaviour looks weird enough and it's better to give their chances to the following callchain users where we failed. Reported-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1375460996-16329-2-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-08-13cgroup: cgroup_css_from_dir() now should be called with RCU read lockedTejun Heo
cgroup->subsys[] will become RCU protected and thus all cgroup_css() usages should either be under RCU read lock or cgroup_mutex. This patch updates cgroup_css_from_dir() which returns the matching cgroup_subsys_state given a directory file and subsys_id so that it requires RCU read lock and updates its sole user perf_cgroup_connect(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com>
2013-08-09cgroup: make cgroup_taskset deal with cgroup_subsys_state instead of cgroupTejun Heo
cgroup is in the process of converting to css (cgroup_subsys_state) from cgroup as the principal subsystem interface handle. This is mostly to prepare for the unified hierarchy support where css's will be created and destroyed dynamically but also helps cleaning up subsystem implementations as css is usually what they are interested in anyway. cgroup_taskset which is used by the subsystem attach methods is the last cgroup subsystem API which isn't using css as the handle. Update cgroup_taskset_cur_cgroup() to cgroup_taskset_cur_css() and cgroup_taskset_for_each() to take @skip_css instead of @skip_cgrp. The conversions are pretty mechanical. One exception is cpuset::cgroup_cs(), which lost its last user and got removed. This patch shouldn't introduce any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org>
2013-08-09cgroup: pass around cgroup_subsys_state instead of cgroup in subsystem methodsTejun Heo
cgroup is currently in the process of transitioning to using struct cgroup_subsys_state * as the primary handle instead of struct cgroup * in subsystem implementations for the following reasons. * With unified hierarchy, subsystems will be dynamically bound and unbound from cgroups and thus css's (cgroup_subsys_state) may be created and destroyed dynamically over the lifetime of a cgroup, which is different from the current state where all css's are allocated and destroyed together with the associated cgroup. This in turn means that cgroup_css() should be synchronized and may return NULL, making it more cumbersome to use. * Differing levels of per-subsystem granularity in the unified hierarchy means that the task and descendant iterators should behave differently depending on the specific subsystem the iteration is being performed for. * In majority of the cases, subsystems only care about its part in the cgroup hierarchy - ie. the hierarchy of css's. Subsystem methods often obtain the matching css pointer from the cgroup and don't bother with the cgroup pointer itself. Passing around css fits much better. This patch converts all cgroup_subsys methods to take @css instead of @cgroup. The conversions are mostly straight-forward. A few noteworthy changes are * ->css_alloc() now takes css of the parent cgroup rather than the pointer to the new cgroup as the css for the new cgroup doesn't exist yet. Knowing the parent css is enough for all the existing subsystems. * In kernel/cgroup.c::offline_css(), unnecessary open coded css dereference is replaced with local variable access. This patch shouldn't cause any behavior differences. v2: Unnecessary explicit cgrp->subsys[] deref in css_online() replaced with local variable @css as suggested by Li Zefan. Rebased on top of new for-3.12 which includes for-3.11-fixes so that ->css_free() invocation added by da0a12caff ("cgroup: fix a leak when percpu_ref_init() fails") is converted too. Suggested by Li Zefan. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Aristeu Rozanski <aris@redhat.com> Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Steven Rostedt <rostedt@goodmis.org>
2013-08-09cgroup: s/cgroup_subsys_state/cgroup_css/ s/task_subsys_state/task_css/Tejun Heo
The names of the two struct cgroup_subsys_state accessors - cgroup_subsys_state() and task_subsys_state() - are somewhat awkward. The former clashes with the type name and the latter doesn't even indicate it's somehow related to cgroup. We're about to revamp large portion of cgroup API, so, let's rename them so that they're less awkward. Most per-controller usages of the accessors are localized in accessor wrappers and given the amount of scheduled changes, this isn't gonna add any noticeable headache. Rename cgroup_subsys_state() to cgroup_css() and task_subsys_state() to task_css(). This patch is pure rename. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-08-07perf: Do not get values from disabled counters in group format readJiri Olsa
It's possible some of the counters in the group could be disabled when sampling member of the event group is reading the rest via PERF_SAMPLE_READ sample type processing. Disabled counters could then produce wrong numbers. Fixing that by reading only enabled counters for PERF_SAMPLE_READ sample type processing. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-wwkjb0bbcuslnz0klrmqi26r@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-08-07perf: Add PERF_EVENT_IOC_ID ioctl to return event IDJiri Olsa
The only way to get the event ID is by reading the event fd, followed by parsing the ID value out of the returned data. While this is ok for current read format used by perf tool, it is not ok when we use PERF_FORMAT_GROUP format. With this format the data are returned for the whole group and there's no way to find out what ID belongs to our fd (if we are not group leader event). Adding a simple ioctl that returns event primary ID for given fd. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-v1bn5cto707jn0bon34afqr1@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-07-30perf: Implement finer grained full dynticks kickFrederic Weisbecker
Currently the full dynticks subsystem keep the tick alive as long as there are perf events running. This prevents the tick from being stopped as long as features such that the lockup detectors are running. As a temporary fix, the lockup detector is disabled by default when full dynticks is built but this is not a long term viable solution. To fix this, only keep the tick alive when an event configured with a frequency rather than a period is running on the CPU, or when an event throttles on the CPU. These are the only purposes of the perf tick, especially now that the rotation of flexible events is handled from a seperate hrtimer. The tick can be shutdown the rest of the time. Original-patch-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1374539466-4799-8-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-30perf: Account freq events per cpuFrederic Weisbecker
This is going to be used by the full dynticks subsystem as a finer-grained information to know when to keep and when to stop the tick. Original-patch-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1374539466-4799-7-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-30perf: Migrate per cpu event accountingFrederic Weisbecker
When an event is migrated, move the event per-cpu accounting accordingly so that branch stack and cgroup events work correctly on the new CPU. Original-patch-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1374539466-4799-6-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-30perf: Split the per-cpu accounting part of the event accounting codeFrederic Weisbecker
This way we can use the per-cpu handling seperately. This is going to be used by to fix the event migration code accounting. Original-patch-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1374539466-4799-5-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-30perf: Factor out event accounting code to account_event()/__free_event()Frederic Weisbecker
Gather all the event accounting code to a single place, once all the prerequisites are completed. This simplifies the refcounting. Original-patch-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1374539466-4799-4-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-30perf: Sanitize get_callchain_buffer()Frederic Weisbecker
In case of allocation failure, get_callchain_buffer() keeps the refcount incremented for the current event. As a result, when get_callchain_buffers() returns an error, we must cleanup what it did by cancelling its last refcount with a call to put_callchain_buffers(). This is a hack in order to be able to call free_event() after that failure. The original purpose of that was to simplify the failure path. But this error handling is actually counter intuitive, ugly and not very easy to follow because one expect to see the resources used to perform a service to be cleaned by the callee if case of failure, not by the caller. So lets clean this up by cancelling the refcount from get_callchain_buffer() in case of failure. And correctly free the event accordingly in perf_event_alloc(). Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1374539466-4799-3-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-30perf: Fix branch stack refcount leak on callchain init failureFrederic Weisbecker
On callchain buffers allocation failure, free_event() is called and all the accounting performed in perf_event_alloc() for that event is cancelled. But if the event has branch stack sampling, it is unaccounted as well from the branch stack sampling events refcounts. This is a bug because this accounting is performed after the callchain buffer allocation. As a result, the branch stack sampling events refcount can become negative. To fix this, move the branch stack event accounting before the callchain buffer allocation. Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1374539466-4799-2-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-23perf: Update perf_event_type documentationPeter Zijlstra
Due to a discussion with Adrian I had a good look at the perf_event_type record layout and found the documentation to be somewhat unclear. Cc: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20130716150907.GL23818@dyad.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-19Merge branch 'linus' into perf/coreIngo Molnar
Merge in a v3.11-rc1-ish branch to go from v3.10 based development to a v3.11 based one. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-18Merge tag 'driver-core-3.11-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core patches from Greg KH: "Here are some driver core patches for 3.11-rc2. They aren't really bugfixes, but a bunch of new helper macros for drivers to properly create attribute groups, which drivers and subsystems need to fix up a ton of race issues with incorrectly creating sysfs files (binary and normal) after userspace has been told that the device is present. Also here is the ability to create binary files as attribute groups, to solve that race condition, which was impossible to do before this, so that's my fault the drivers were broken. The majority of the .c changes is indenting and moving code around a bit. It affects no existing code, but allows the large backlog of 70+ patches that I already have created to start flowing into the different subtrees, instead of having to live in my driver-core tree, causing merge nightmares in linux-next for the next few months. These were finalized too late for the -rc1 merge window, which is why they were didn't make that pull request, testing and review from others didn't happen until a few weeks ago, and then there's the whole distraction of the past few days, which prevented these from getting to you sooner, sorry about that. Oh, and there's a bugfix for the documentation build warning in here as well. All of these have been in linux-next this week, with no reported problems" * tag 'driver-core-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: driver-core: fix new kernel-doc warning in base/platform.c sysfs: use file mode defines from stat.h sysfs: add more helper macro's for (bin_)attribute(_groups) driver core: add default groups to struct class driver core: Introduce device_create_groups sysfs: prevent warning when only using binary attributes sysfs: add support for binary attributes in groups driver core: device.h: add RW and RO attribute macros sysfs.h: add BIN_ATTR macro sysfs.h: add ATTRIBUTE_GROUPS() macro sysfs.h: add __ATTR_RW() macro
2013-07-16sysfs.h: add __ATTR_RW() macroGreg Kroah-Hartman
A number of parts of the kernel created their own version of this, might as well have the sysfs core provide it instead. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-14kernel: delete __cpuinit usage from all core kernel filesPaul Gortmaker
The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the uses of the __cpuinit macros from C files in the core kernel directories (kernel, init, lib, mm, and include) that don't really have a specific maintainer. [1] https://lkml.org/lkml/2013/5/20/589 Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-07-12perf: Remove the 'match' callback for auxiliary events processingJiri Olsa
It gives the following benefits: - only one function pointer is passed along the way - the 'match' function is called within output function and could be inlined by the compiler Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1373388991-9711-1-git-send-email-jolsa@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-12perf: Fix perf_lock_task_context() vs RCUPeter Zijlstra
Jiri managed to trigger this warning: [] ====================================================== [] [ INFO: possible circular locking dependency detected ] [] 3.10.0+ #228 Tainted: G W [] ------------------------------------------------------- [] p/6613 is trying to acquire lock: [] (rcu_node_0){..-...}, at: [<ffffffff810ca797>] rcu_read_unlock_special+0xa7/0x250 [] [] but task is already holding lock: [] (&ctx->lock){-.-...}, at: [<ffffffff810f2879>] perf_lock_task_context+0xd9/0x2c0 [] [] which lock already depends on the new lock. [] [] the existing dependency chain (in reverse order) is: [] [] -> #4 (&ctx->lock){-.-...}: [] -> #3 (&rq->lock){-.-.-.}: [] -> #2 (&p->pi_lock){-.-.-.}: [] -> #1 (&rnp->nocb_gp_wq[1]){......}: [] -> #0 (rcu_node_0){..-...}: Paul was quick to explain that due to preemptible RCU we cannot call rcu_read_unlock() while holding scheduler (or nested) locks when part of the read side critical section was preemptible. Therefore solve it by making the entire RCU read side non-preemptible. Also pull out the retry from under the non-preempt to play nice with RT. Reported-by: Jiri Olsa <jolsa@redhat.com> Helped-out-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-12perf: Remove WARN_ON_ONCE() check in __perf_event_enable() for valid scenarioJiri Olsa
The '!ctx->is_active' check has a valid scenario, so there's no need for the warning. The reason is that there's a time window between the 'ctx->is_active' check in the perf_event_enable() function and the __perf_event_enable() function having: - IRQs on - ctx->lock unlocked where the task could be killed and 'ctx' deactivated by perf_event_exit_task(), ending up with the warning below. So remove the WARN_ON_ONCE() check and add comments to explain it all. This addresses the following warning reported by Vince Weaver: [ 324.983534] ------------[ cut here ]------------ [ 324.984420] WARNING: at kernel/events/core.c:1953 __perf_event_enable+0x187/0x190() [ 324.984420] Modules linked in: [ 324.984420] CPU: 19 PID: 2715 Comm: nmi_bug_snb Not tainted 3.10.0+ #246 [ 324.984420] Hardware name: Supermicro X8DTN/X8DTN, BIOS 4.6.3 01/08/2010 [ 324.984420] 0000000000000009 ffff88043fce3ec8 ffffffff8160ea0b ffff88043fce3f00 [ 324.984420] ffffffff81080ff0 ffff8802314fdc00 ffff880231a8f800 ffff88043fcf7860 [ 324.984420] 0000000000000286 ffff880231a8f800 ffff88043fce3f10 ffffffff8108103a [ 324.984420] Call Trace: [ 324.984420] <IRQ> [<ffffffff8160ea0b>] dump_stack+0x19/0x1b [ 324.984420] [<ffffffff81080ff0>] warn_slowpath_common+0x70/0xa0 [ 324.984420] [<ffffffff8108103a>] warn_slowpath_null+0x1a/0x20 [ 324.984420] [<ffffffff81134437>] __perf_event_enable+0x187/0x190 [ 324.984420] [<ffffffff81130030>] remote_function+0x40/0x50 [ 324.984420] [<ffffffff810e51de>] generic_smp_call_function_single_interrupt+0xbe/0x130 [ 324.984420] [<ffffffff81066a47>] smp_call_function_single_interrupt+0x27/0x40 [ 324.984420] [<ffffffff8161fd2f>] call_function_single_interrupt+0x6f/0x80 [ 324.984420] <EOI> [<ffffffff816161a1>] ? _raw_spin_unlock_irqrestore+0x41/0x70 [ 324.984420] [<ffffffff8113799d>] perf_event_exit_task+0x14d/0x210 [ 324.984420] [<ffffffff810acd04>] ? switch_task_namespaces+0x24/0x60 [ 324.984420] [<ffffffff81086946>] do_exit+0x2b6/0xa40 [ 324.984420] [<ffffffff8161615c>] ? _raw_spin_unlock_irq+0x2c/0x30 [ 324.984420] [<ffffffff81087279>] do_group_exit+0x49/0xc0 [ 324.984420] [<ffffffff81096854>] get_signal_to_deliver+0x254/0x620 [ 324.984420] [<ffffffff81043057>] do_signal+0x57/0x5a0 [ 324.984420] [<ffffffff8161a164>] ? __do_page_fault+0x2a4/0x4e0 [ 324.984420] [<ffffffff8161665c>] ? retint_restore_args+0xe/0xe [ 324.984420] [<ffffffff816166cd>] ? retint_signal+0x11/0x84 [ 324.984420] [<ffffffff81043605>] do_notify_resume+0x65/0x80 [ 324.984420] [<ffffffff81616702>] retint_signal+0x46/0x84 [ 324.984420] ---[ end trace 442ec2f04db3771a ]--- Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1373384651-6109-2-git-send-email-jolsa@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-12perf: Clone child context from parent context pmuJiri Olsa
Currently when the child context for inherited events is created, it's based on the pmu object of the first event of the parent context. This is wrong for the following scenario: - HW context having HW and SW event - HW event got removed (closed) - SW event stays in HW context as the only event and its pmu is used to clone the child context The issue starts when the cpu context object is touched based on the pmu context object (__get_cpu_context). In this case the HW context will work with SW cpu context ending up with following WARN below. Fixing this by using parent context pmu object to clone from child context. Addresses the following warning reported by Vince Weaver: [ 2716.472065] ------------[ cut here ]------------ [ 2716.476035] WARNING: at kernel/events/core.c:2122 task_ctx_sched_out+0x3c/0x) [ 2716.476035] Modules linked in: nfsd auth_rpcgss oid_registry nfs_acl nfs locn [ 2716.476035] CPU: 0 PID: 3164 Comm: perf_fuzzer Not tainted 3.10.0-rc4 #2 [ 2716.476035] Hardware name: AOpen DE7000/nMCP7ALPx-DE R1.06 Oct.19.2012, BI2 [ 2716.476035] 0000000000000000 ffffffff8102e215 0000000000000000 ffff88011fc18 [ 2716.476035] ffff8801175557f0 0000000000000000 ffff880119fda88c ffffffff810ad [ 2716.476035] ffff880119fda880 ffffffff810af02a 0000000000000009 ffff880117550 [ 2716.476035] Call Trace: [ 2716.476035] [<ffffffff8102e215>] ? warn_slowpath_common+0x5b/0x70 [ 2716.476035] [<ffffffff810ab2bd>] ? task_ctx_sched_out+0x3c/0x5f [ 2716.476035] [<ffffffff810af02a>] ? perf_event_exit_task+0xbf/0x194 [ 2716.476035] [<ffffffff81032a37>] ? do_exit+0x3e7/0x90c [ 2716.476035] [<ffffffff810cd5ab>] ? __do_fault+0x359/0x394 [ 2716.476035] [<ffffffff81032fe6>] ? do_group_exit+0x66/0x98 [ 2716.476035] [<ffffffff8103dbcd>] ? get_signal_to_deliver+0x479/0x4ad [ 2716.476035] [<ffffffff810ac05c>] ? __perf_event_task_sched_out+0x230/0x2d1 [ 2716.476035] [<ffffffff8100205d>] ? do_signal+0x3c/0x432 [ 2716.476035] [<ffffffff810abbf9>] ? ctx_sched_in+0x43/0x141 [ 2716.476035] [<ffffffff810ac2ca>] ? perf_event_context_sched_in+0x7a/0x90 [ 2716.476035] [<ffffffff810ac311>] ? __perf_event_task_sched_in+0x31/0x118 [ 2716.476035] [<ffffffff81050dd9>] ? mmdrop+0xd/0x1c [ 2716.476035] [<ffffffff81051a39>] ? finish_task_switch+0x7d/0xa6 [ 2716.476035] [<ffffffff81002473>] ? do_notify_resume+0x20/0x5d [ 2716.476035] [<ffffffff813654f5>] ? retint_signal+0x3d/0x78 [ 2716.476035] ---[ end trace 827178d8a5966c3d ]--- Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1373384651-6109-1-git-send-email-jolsa@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-05perf: Fix interrupt handler timing harnessStephane Eranian
This patch fixes a serious bug in: 14c63f17b1fd perf: Drop sample rate when sampling is too slow There was an misunderstanding on the API of the do_div() macro. It returns the remainder of the division and this was not what the function expected leading to disabling the interrupt latency watchdog. This patch also remove a duplicate assignment in perf_sample_event_took(). Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Cc: dave.hansen@linux.intel.com Cc: ak@linux.intel.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/20130704223010.GA30625@quad Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-23perf: Drop sample rate when sampling is too slowDave Hansen
This patch keeps track of how long perf's NMI handler is taking, and also calculates how many samples perf can take a second. If the sample length times the expected max number of samples exceeds a configurable threshold, it drops the sample rate. This way, we don't have a runaway sampling process eating up the CPU. This patch can tend to drop the sample rate down to level where perf doesn't work very well. *BUT* the alternative is that my system hangs because it spends all of its time handling NMIs. I'll take a busted performance tool over an entire system that's busted and undebuggable any day. BTW, my suspicion is that there's still an underlying bug here. Using the HPET instead of the TSC is definitely a contributing factor, but I suspect there are some other things going on. But, I can't go dig down on a bug like that with my machine hanging all the time. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org Cc: acme@ghostprotocols.net Cc: Dave Hansen <dave@sr71.net> [ Prettified it a bit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-20hw_breakpoint: Introduce "struct bp_cpuinfo"Oleg Nesterov
This patch simply moves all per-cpu variables into the new single per-cpu "struct bp_cpuinfo". To me this looks more logical and clean, but this can also simplify the further potential changes. In particular, I do not think this memory should be per-cpu, it is never used "locally". After this change it is trivial to turn it into, say, bootmem[nr_cpu_ids]. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20130620155020.GA6350@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-20hw_breakpoint: Simplify *register_wide_hw_breakpoint()Oleg Nesterov
1. register_wide_hw_breakpoint() can use unregister_ if failure, no need to duplicate the code. 2. "struct perf_event **pevent" adds the unnecesary lever of indirection and complication, use per_cpu(*cpu_events, cpu). Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20130620155018.GA6347@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-20hw_breakpoint: Introduce cpumask_of_bp()Oleg Nesterov
Add the trivial helper which simply returns cpumask_of() or cpu_possible_mask depending on bp->cpu. Change fetch_bp_busy_slots() and toggle_bp_slot() to always do for_each_cpu(cpumask_of_bp) to simplify the code and avoid the code duplication. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20130620155015.GA6340@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-20hw_breakpoint: Simplify the "weight" usage in toggle_bp_slot() pathsOleg Nesterov
Change toggle_bp_slot() to make "weight" negative if !enable. This way we can always use "+ weight" without additional "if (enable)" check and toggle_bp_task_slot() no longer needs this arg. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20130620155013.GA6337@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-20hw_breakpoint: Simplify list/idx mess in toggle_bp_slot() pathsOleg Nesterov
The enable/disable logic in toggle_bp_slot() is not symmetrical and imho very confusing. "old_count" in toggle_bp_task_slot() is actually new_count because this bp was already removed from the list. Change toggle_bp_slot() to always call list_add/list_del after toggle_bp_task_slot(). This way old_idx is task_bp_pinned() and this entry should be decremented, new_idx is +/-weight and we need to increment this element. The code/logic looks obvious. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20130620155011.GA6330@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>