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2014-10-15Merge branch 'for-3.18-consistent-ops' of ↵Linus Torvalds2-14/+14
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu Pull percpu consistent-ops changes from Tejun Heo: "Way back, before the current percpu allocator was implemented, static and dynamic percpu memory areas were allocated and handled separately and had their own accessors. The distinction has been gone for many years now; however, the now duplicate two sets of accessors remained with the pointer based ones - this_cpu_*() - evolving various other operations over time. During the process, we also accumulated other inconsistent operations. This pull request contains Christoph's patches to clean up the duplicate accessor situation. __get_cpu_var() uses are replaced with with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr(). Unfortunately, the former sometimes is tricky thanks to C being a bit messy with the distinction between lvalues and pointers, which led to a rather ugly solution for cpumask_var_t involving the introduction of this_cpu_cpumask_var_ptr(). This converts most of the uses but not all. Christoph will follow up with the remaining conversions in this merge window and hopefully remove the obsolete accessors" * 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits) irqchip: Properly fetch the per cpu offset percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write. percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t Revert "powerpc: Replace __get_cpu_var uses" percpu: Remove __this_cpu_ptr clocksource: Replace __this_cpu_ptr with raw_cpu_ptr sparc: Replace __get_cpu_var uses avr32: Replace __get_cpu_var with __this_cpu_write blackfin: Replace __get_cpu_var uses tile: Use this_cpu_ptr() for hardware counters tile: Replace __get_cpu_var uses powerpc: Replace __get_cpu_var uses alpha: Replace __get_cpu_var ia64: Replace __get_cpu_var uses s390: cio driver &__get_cpu_var replacements s390: Replace __get_cpu_var uses mips: Replace __get_cpu_var uses MIPS: Replace __get_cpu_var uses in FPU emulator. arm: Replace __this_cpu_ptr with raw_cpu_ptr ...
2014-10-13Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-23/+31
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Two leftover fixes from the v3.17 cycle - these will be forwarded to stable as well, if they prove problem-free in wider testing as well" [ Side note: the "fix perf bug in fork()" fix had also come in through Andrew's patch-bomb - Linus ] * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix perf bug in fork() perf: Fix unclone_ctx() vs. locking
2014-10-13Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2-15/+145
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Kernel side updates: - Fix and enhance poll support (Jiri Olsa) - Re-enable inheritance optimization (Jiri Olsa) - Enhance Intel memory events support (Stephane Eranian) - Refactor the Intel uncore driver to be more maintainable (Zheng Yan) - Enhance and fix Intel CPU and uncore PMU drivers (Peter Zijlstra, Andi Kleen) - [ plus various smaller fixes/cleanups ] User visible tooling updates: - Add +field argument support for --field option, so that one can add fields to the default list of fields to show, ie now one can just do: perf report --fields +pid And the pid will appear in addition to the default fields (Jiri Olsa) - Add +field argument support for --sort option (Jiri Olsa) - Honour -w in the report tools (report, top), allowing to specify the widths for the histogram entries columns (Namhyung Kim) - Properly show submicrosecond times in 'perf kvm stat' (Christian Borntraeger) - Add beautifier for mremap flags param in 'trace' (Alex Snast) - perf script: Allow callchains if any event samples them - Don't truncate Intel style addresses in 'annotate' (Alex Converse) - Allow profiling when kptr_restrict == 1 for non root users, kernel samples will just remain unresolved (Andi Kleen) - Allow configuring default options for callchains in config file (Namhyung Kim) - Support operations for shared futexes. (Davidlohr Bueso) - "perf kvm stat report" improvements by Alexander Yarygin: - Save pid string in opts.target.pid - Enable the target.system_wide flag - Unify the title bar output - [ plus lots of other fixes and small improvements. ] Tooling infrastructure changes: - Refactor unit and scale function parameters for PMU parsing routines (Matt Fleming) - Improve DSO long names lookup with rbtree, resulting in great speedup for workloads with lots of DSOs (Waiman Long) - We were not handling POLLHUP notifications for event file descriptors Fix it by filtering entries in the events file descriptor array after poll() returns, refcounting mmaps so that when the last fd pointing to a perf mmap goes away we do the unmap (Arnaldo Carvalho de Melo) - Intel PT prep work, from Adrian Hunter, including: - Let a user specify a PMU event without any config terms - Add perf-with-kcore script - Let default config be defined for a PMU - Add perf_pmu__scan_file() - Add a 'perf test' for tracking with sched_switch - Add 'flush' callback to scripting API - Use ring buffer consume method to look like other tools (Arnaldo Carvalho de Melo) - hists browser (used in top and report) refactorings, getting rid of unused variables and reducing source code size by handling similar cases in a fewer functions (Namhyung Kim). - Replace thread unsafe strerror() with strerror_r() accross the whole tools/perf/ tree (Masami Hiramatsu) - Rename ordered_samples to ordered_events and allow setting a queue size for ordering events (Jiri Olsa) - [ plus lots of fixes, cleanups and other improvements ]" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (198 commits) perf/x86: Tone down kernel messages when the PMU check fails in a virtual environment perf/x86/intel/uncore: Fix minor race in box set up perf record: Fix error message for --filter option not coming after tracepoint perf tools: Fix build breakage on arm64 targets perf symbols: Improve DSO long names lookup speed with rbtree perf symbols: Encapsulate dsos list head into struct dsos perf bench futex: Sanitize -q option in requeue perf bench futex: Support operations for shared futexes perf trace: Fix mmap return address truncation to 32-bit perf tools: Refactor unit and scale function parameters perf tools: Fix line number in the config file error message perf tools: Convert {record,top}.call-graph option to call-graph.record-mode perf tools: Introduce perf_callchain_config() perf callchain: Move some parser functions to callchain.c perf tools: Move callchain config from record_opts to callchain_param perf hists browser: Fix callchain print bug on TUI perf tools: Use ACCESS_ONCE() instead of volatile cast perf tools: Modify error code for when perf_session__new() fails perf tools: Fix perf record as non root with kptr_restrict == 1 perf stat: Fix --per-core on multi socket systems ...
2014-10-10Merge branch 'for-3.18' of ↵Linus Torvalds1-6/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Nothing too interesting. Just a handful of cleanup patches" * 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: Revert "cgroup: remove redundant variable in cgroup_mount()" cgroup: remove redundant variable in cgroup_mount() cgroup: fix missing unlock in cgroup_release_agent() cgroup: remove CGRP_RELEASABLE flag perf/cgroup: Remove perf_put_cgroup() cgroup: remove redundant check in cgroup_ino() cpuset: simplify proc_cpuset_show() cgroup: simplify proc_cgroup_show() cgroup: use a per-cgroup work for release agent cgroup: remove bogus comments cgroup: remove redundant code in cgroup_rmdir() cgroup: remove some useless forward declarations cgroup: fix a typo in comment.
2014-10-03perf: Fix perf bug in fork()Peter Zijlstra1-1/+3
Oleg noticed that a cleanup by Sylvain actually uncovered a bug; by calling perf_event_free_task() when failing sched_fork() we will not yet have done the memset() on ->perf_event_ctxp[] and will therefore try and 'free' the inherited contexts, which are still in use by the parent process. This is bad and might explain some outstanding fuzzer failures ... Suggested-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Sylvain 'ythier' Hitier <sylvain.hitier@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Daeseok Youn <daeseok.youn@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Rik van Riel <riel@redhat.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20140929101201.GE5430@worktop Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-03perf: Fix unclone_ctx() vs. lockingPeter Zijlstra1-23/+31
The idiot who did 4a1c0f262f88 ("perf: Fix lockdep warning on process exit") forgot to pay attention and fix all similar cases. Do so now. In particular, unclone_ctx() must be called while holding ctx->lock, therefore all such sites are broken for the same reason. Pull the put_ctx() call out from under ctx->lock. Reported-by: Sasha Levin <sasha.levin@oracle.com> Probably-also-reported-by: Vince Weaver <vincent.weaver@maine.edu> Fixes: 4a1c0f262f88 ("perf: Fix lockdep warning on process exit") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Cong Wang <cwang@twopensource.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140930172308.GI4241@worktop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-02perf: fix perf bug in fork()Peter Zijlstra1-1/+3
Oleg noticed that a cleanup by Sylvain actually uncovered a bug; by calling perf_event_free_task() when failing sched_fork() we will not yet have done the memset() on ->perf_event_ctxp[] and will therefore try and 'free' the inherited contexts, which are still in use by the parent process. This is bad.. Suggested-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Sylvain 'ythier' Hitier <sylvain.hitier@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-09-24Revert "perf: Do not allow optimized switch for non-cloned events"Jiri Olsa1-1/+1
This reverts commit 1f9a7268c67f0290837aada443d28fd953ddca90. With the fix of the initial state for the cloned event we now correctly handle the error described in: 1f9a7268c67f perf: Do not allow optimized switch for non-cloned events so we can revert it. I made an automated test for this, but its not suitable for automated perf tests framework. It needs to be customized for each machine (the more cpu the higher numbers for GROUPS/WORKERS/BYTES) and it could take longer time to hit the issue. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Stephane Eranian <eranian@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140910143535.GD2409@krava.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-24perf: Fix child event initial state setupJiri Olsa1-1/+2
Currently we initialize the child event based on the original parent state. This is wrong, because the original parent event (and its state) is not related to current fork and also could be already gone. We need to initialize the child state based on the immediate parent event state. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Stephane Eranian <eranian@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1410520708-19275-2-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-24perf: Do not POLLHUP event if it has childrenJiri Olsa1-1/+20
Currently we return POLLHUP in event polling if the monitored process is done, but we didn't consider possible children, that might be still running and producing data. Before returning POLLHUP making sure that: 1) the monitored task has exited and that 2) we don't have any children to monitor Also adding parent wakeup when the child event is gone. Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/1410520708-19275-1-git-send-email-jolsa@kernel.org Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-19perf/cgroup: Remove perf_put_cgroup()Zefan Li1-6/+1
Commit 5a17f543ed68 ("cgroup: improve css_from_dir() into css_tryget_from_dir()") removed perf_tryget_cgroup(), so let's also remove perf_put_cgroup(). Signed-off-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2014-09-16perf: Do not check PERF_EVENT_STATE_EXIT on syscall read pathJiri Olsa1-2/+1
Revert PERF_EVENT_STATE_EXIT check on read syscall path. It breaks standard way to read counter, which is to open the counter, wait for the monitored process to die and read the counter. Reported-by: Stephane Eranian <eranian@google.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> Cc: David Ahern <dsahern@gmail.com> Link: http://lkml.kernel.org/r/20140908143107.GG17728@krava.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-09perf: Fix a race condition in perf_remove_from_context()Cong Wang1-0/+10
We saw a kernel soft lockup in perf_remove_from_context(), it looks like the `perf` process, when exiting, could not go out of the retry loop. Meanwhile, the target process was forking a child. So either the target process should execute the smp function call to deactive the event (if it was running) or it should do a context switch which deactives the event. It seems we optimize out a context switch in perf_event_context_sched_out(), and what's more important, we still test an obsolete task pointer when retrying, so no one actually would deactive that event in this situation. Fix it directly by reloading the task pointer in perf_remove_from_context(). This should cure the above soft lockup. Signed-off-by: Cong Wang <cwang@twopensource.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/1409696840-843-1-git-send-email-xiyou.wangcong@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-09perf/core: Replace rcu_assign_pointer() with RCU_INIT_POINTER()Andreea-Cristina Bernat1-1/+1
The use of "rcu_assign_pointer()" is NULLing out the pointer. According to RCU_INIT_POINTER()'s block comment: "1. This use of RCU_INIT_POINTER() is NULLing out the pointer" it is better to use it instead of rcu_assign_pointer() because it has a smaller overhead. The following Coccinelle semantic patch was used: @@ @@ - rcu_assign_pointer + RCU_INIT_POINTER (..., NULL) Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Link: http://lkml.kernel.org/r/20140822132605.GA20130@ada Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-09perf/callchain: Replace rcu_assign_pointer() with RCU_INIT_POINTER()Andreea-Cristina Bernat1-1/+1
The use of "rcu_assign_pointer()" is NULLing out the pointer. According to RCU_INIT_POINTER()'s block comment: "1. This use of RCU_INIT_POINTER() is NULLing out the pointer" it is better to use it instead of rcu_assign_pointer() because it has a smaller overhead. The following Coccinelle semantic patch was used: @@ @@ - rcu_assign_pointer + RCU_INIT_POINTER (..., NULL) Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: paulmck@linux.vnet.ibm.com Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Link: http://lkml.kernel.org/r/20140822141536.GA32051@ada Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-09Merge tag 'v3.17-rc4' into perf/core, to pick up fixesIngo Molnar1-1/+22
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-26scheduler: Replace __get_cpu_var with this_cpu_ptrChristoph Lameter2-14/+14
Convert all uses of __get_cpu_var for address calculation to use this_cpu_ptr instead. [Uses of __get_cpu_var with cpumask_var_t are no longer handled by this patch] Cc: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-24Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-1/+22
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "A kprobes and a perf compat ioctl fix" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Handle compat ioctl kprobes: Skip kretprobe hit in NMI context to avoid deadlock
2014-08-24Merge branch 'linus' into perf/core, to fix conflictsIngo Molnar1-7/+8
Conflicts: arch/x86/kernel/cpu/perf_event_intel_uncore*.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-24perf: Add PERF_EVENT_STATE_EXIT state for events with exited taskJiri Olsa1-1/+9
Adding new perf event state to indicate that the monitored task has exited. In this case the event stays alive until the owner task exits or close the event fd while providing the last data through the read syscall and ring buffer. Instead it needs to propagate the error info (monitored task has died) via poll and read syscalls by returning POLLHUP and 0 respectively. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140811120102.GY9918@twins.programming.kicks-ass.net Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jean Pihet <jean.pihet@linaro.org> 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-t5y3w8jjx6tfo5w8y6oajsjq@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-08-24perf: Fix perf_poll to return proper POLLHUP valueJiri Olsa1-1/+1
Currently perf_poll returns POLL_HUP in case of error, which is wrong, because poll syscall expects POLLHUP. The POLL_HUP is meant to be used for SIGIO state. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140811120102.GY9918@twins.programming.kicks-ass.net Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jean Pihet <jean.pihet@linaro.org> 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-0ywfthh4lh65swe15f6w2x2q@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-08-20perf: Handle compat ioctlPawel Moll1-1/+22
When running a 32-bit userspace on a 64-bit kernel (eg. i386 application on x86_64 kernel or 32-bit arm userspace on arm64 kernel) some of the perf ioctls must be treated with special care, as they have a pointer size encoded in the command. For example, PERF_EVENT_IOC_ID in 32-bit world will be encoded as 0x80042407, but 64-bit kernel will expect 0x80082407. In result the ioctl will fail returning -ENOTTY. This patch solves the problem by adding code fixing up the size as compat_ioctl file operation. Reported-by: Drew Richardson <drew.richardson@arm.com> Signed-off-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/1402671812-9078-1-git-send-email-pawel.moll@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-13perf: Do poll_wait() before checking condition in perf_poll()Sebastian Andrzej Siewior1-3/+1
One should first enqueue to the waitqueue and then check for the condition. If the condition gets true after mutex_unlock() but before poll_wait() then we lose it and would have wait for another wakeup. This has been like this since v2.6.31-rc1 commit c7138f37f9 ("perf_counter: fix perf_poll()"). Before that it was slightly worse. I guess we get enough wakeups so if we miss here one it doesn't really matter. It is still a bad example. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1407159068-1478-1-git-send-email-bigeasy@linutronix.de Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-13perf: Add queued work to remove orphaned child eventsJiri Olsa1-1/+86
In cases when the owner task exits before the workload and the workload made some forks, all the events stay in until the last workload process exits. Thats' because each child event holds parent reference. We want to release all children events once the parent is gone, because at that time there's no process to read them anyway, so they're just eating resources. This removal races with process exit, which removes all events and fork, which clone events. To be clear of those two, adding work queue to remove orphaned child for context in case such event is detected. Using delayed work queue (with delay == 1), because we queue this work under perf scheduler callbacks. Normal work queue tries to wake up the queue process, which deadlocks on rq->lock in this place. Also preventing clones from abandoned parent event. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1406896382-18404-4-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-13perf: Set owner pointer for kernel eventsJiri Olsa1-6/+26
Adding fake EVENT_OWNER_KERNEL owner pointer value for kernel perf events, so we could distinguish it from user events, which needs special care in following patch. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1406896382-18404-3-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-08mm: memcontrol: rewrite charge APIJohannes Weiner1-7/+8
These patches rework memcg charge lifetime to integrate more naturally with the lifetime of user pages. This drastically simplifies the code and reduces charging and uncharging overhead. The most expensive part of charging and uncharging is the page_cgroup bit spinlock, which is removed entirely after this series. Here are the top-10 profile entries of a stress test that reads a 128G sparse file on a freshly booted box, without even a dedicated cgroup (i.e. executing in the root memcg). Before: 15.36% cat [kernel.kallsyms] [k] copy_user_generic_string 13.31% cat [kernel.kallsyms] [k] memset 11.48% cat [kernel.kallsyms] [k] do_mpage_readpage 4.23% cat [kernel.kallsyms] [k] get_page_from_freelist 2.38% cat [kernel.kallsyms] [k] put_page 2.32% cat [kernel.kallsyms] [k] __mem_cgroup_commit_charge 2.18% kswapd0 [kernel.kallsyms] [k] __mem_cgroup_uncharge_common 1.92% kswapd0 [kernel.kallsyms] [k] shrink_page_list 1.86% cat [kernel.kallsyms] [k] __radix_tree_lookup 1.62% cat [kernel.kallsyms] [k] __pagevec_lru_add_fn After: 15.67% cat [kernel.kallsyms] [k] copy_user_generic_string 13.48% cat [kernel.kallsyms] [k] memset 11.42% cat [kernel.kallsyms] [k] do_mpage_readpage 3.98% cat [kernel.kallsyms] [k] get_page_from_freelist 2.46% cat [kernel.kallsyms] [k] put_page 2.13% kswapd0 [kernel.kallsyms] [k] shrink_page_list 1.88% cat [kernel.kallsyms] [k] __radix_tree_lookup 1.67% cat [kernel.kallsyms] [k] __pagevec_lru_add_fn 1.39% kswapd0 [kernel.kallsyms] [k] free_pcppages_bulk 1.30% cat [kernel.kallsyms] [k] kfree As you can see, the memcg footprint has shrunk quite a bit. text data bss dec hex filename 37970 9892 400 48262 bc86 mm/memcontrol.o.old 35239 9892 400 45531 b1db mm/memcontrol.o This patch (of 4): The memcg charge API charges pages before they are rmapped - i.e. have an actual "type" - and so every callsite needs its own set of charge and uncharge functions to know what type is being operated on. Worse, uncharge has to happen from a context that is still type-specific, rather than at the end of the page's lifetime with exclusive access, and so requires a lot of synchronization. Rewrite the charge API to provide a generic set of try_charge(), commit_charge() and cancel_charge() transaction operations, much like what's currently done for swap-in: mem_cgroup_try_charge() attempts to reserve a charge, reclaiming pages from the memcg if necessary. mem_cgroup_commit_charge() commits the page to the charge once it has a valid page->mapping and PageAnon() reliably tells the type. mem_cgroup_cancel_charge() aborts the transaction. This reduces the charge API and enables subsequent patches to drastically simplify uncharging. As pages need to be committed after rmap is established but before they are added to the LRU, page_add_new_anon_rmap() must stop doing LRU additions again. Revive lru_cache_add_active_or_unevictable(). [hughd@google.com: fix shmem_unuse] [hughd@google.com: Add comments on the private use of -EAGAIN] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-07-28Merge tag 'v3.16-rc7' into perf/core, to merge in the latest fixes before ↵Ingo Molnar2-6/+34
applying new changes Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-27Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-2/+30
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "A bunch of fixes for perf and kprobes: - revert a commit that caused a perf group regression - silence dmesg spam - fix kprobe probing errors on ia64 and ppc64 - filter kprobe faults from userspace - lockdep fix for perf exit path - prevent perf #GP in KVM guest - correct perf event and filters" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kprobes: Fix "Failed to find blacklist" probing errors on ia64 and ppc64 kprobes/x86: Don't try to resolve kprobe faults from userspace perf/x86/intel: Avoid spamming kernel log for BTS buffer failure perf/x86/intel: Protect LBR and extra_regs against KVM lying perf: Fix lockdep warning on process exit perf/x86/intel/uncore: Fix SNB-EP/IVT Cbox filter mappings perf/x86/intel: Use proper dTLB-load-misses event on IvyBridge perf: Revert ("perf: Always destroy groups on exit")
2014-07-16Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Tooling fixes and an Intel PMU driver fixlet" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Do not allow optimized switch for non-cloned events perf/x86/intel: ignore CondChgd bit to avoid false NMI handling perf symbols: Get kernel start address by symbol name perf tools: Fix segfault in cumulative.callchain report
2014-07-16perf: Add vm_ops->name call for mmap event name retrievalJiri Olsa1-0/+6
The following patch added another way to get mmap name: 78d683e838a6 ("mm, fs: Add vm_ops->name as an alternative to arch_vma_name") The vdso vma mapping already switch to this and we no longer get vdso name via arch_vma_name function. Adding this way to the perf mmap event name retrieval code. Caught this via perf test: $ sudo ./perf test -v 7 7: Validate PERF_RECORD_* events & perf_sample fields : --- start --- SNIP PERF_RECORD_MMAP for [vdso] missing! test child finished with 255 ---- end ---- Validate PERF_RECORD_* events & perf_sample fields: FAILED! Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1405353439-14211-1-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16perf: Fix lockdep warning on process exitPeter Zijlstra1-1/+17
Sasha Levin reported: > While fuzzing with trinity inside a KVM tools guest running the latest -next > kernel I've stumbled on the following spew: > > ====================================================== > [ INFO: possible circular locking dependency detected ] > 3.15.0-next-20140613-sasha-00026-g6dd125d-dirty #654 Not tainted > ------------------------------------------------------- > trinity-c578/9725 is trying to acquire lock: > (&(&pool->lock)->rlock){-.-...}, at: __queue_work (kernel/workqueue.c:1346) > > but task is already holding lock: > (&ctx->lock){-.....}, at: perf_event_exit_task (kernel/events/core.c:7471 kernel/events/core.c:7533) > > which lock already depends on the new lock. > 1 lock held by trinity-c578/9725: > #0: (&ctx->lock){-.....}, at: perf_event_exit_task (kernel/events/core.c:7471 kernel/events/core.c:7533) > > Call Trace: > dump_stack (lib/dump_stack.c:52) > print_circular_bug (kernel/locking/lockdep.c:1216) > __lock_acquire (kernel/locking/lockdep.c:1840 kernel/locking/lockdep.c:1945 kernel/locking/lockdep.c:2131 kernel/locking/lockdep.c:3182) > lock_acquire (./arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602) > _raw_spin_lock (include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:151) > __queue_work (kernel/workqueue.c:1346) > queue_work_on (kernel/workqueue.c:1424) > free_object (lib/debugobjects.c:209) > __debug_check_no_obj_freed (lib/debugobjects.c:715) > debug_check_no_obj_freed (lib/debugobjects.c:727) > kmem_cache_free (mm/slub.c:2683 mm/slub.c:2711) > free_task (kernel/fork.c:221) > __put_task_struct (kernel/fork.c:250) > put_ctx (include/linux/sched.h:1855 kernel/events/core.c:898) > perf_event_exit_task (kernel/events/core.c:907 kernel/events/core.c:7478 kernel/events/core.c:7533) > do_exit (kernel/exit.c:766) > do_group_exit (kernel/exit.c:884) > get_signal_to_deliver (kernel/signal.c:2347) > do_signal (arch/x86/kernel/signal.c:698) > do_notify_resume (arch/x86/kernel/signal.c:751) > int_signal (arch/x86/kernel/entry_64.S:600) Urgh.. so the only way I can make that happen is through: perf_event_exit_task_context() raw_spin_lock(&child_ctx->lock); unclone_ctx(child_ctx) put_ctx(ctx->parent_ctx); raw_spin_unlock_irqrestore(&child_ctx->lock); And we can avoid this by doing the change below. I can't immediately see how this changed recently, but given that you say it's easy to reproduce, lets fix this. Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Dave Jones <davej@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140623141242.GB19860@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16perf: Revert ("perf: Always destroy groups on exit")Peter Zijlstra1-1/+13
Vince reported that commit 15a2d4de0eab5 ("perf: Always destroy groups on exit") causes a regression with grouped events. In particular his read_group_attached.c test fails. https://github.com/deater/perf_event_tests/blob/master/tests/bugs/read_group_attached.c Because of the context switch optimization in perf_event_context_sched_out() the 'original' event may end up in the child process and when that exits the change in the patch in question destroys the actual grouping. Therefore revert that change and only destroy inherited groups. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-zedy3uktcp753q8fw8dagx7a@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-05perf: Make perf_event_init_context() function staticJiri Olsa1-1/+1
Leftover from '8dc85d5 perf: Multiple task contexts'. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/1403598026-2310-1-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-03Merge tag 'trace-fixes-v3.16-rc3' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Oleg Nesterov found and fixed a bug in the perf/ftrace/uprobes code where running: # perf probe -x /lib/libc.so.6 syscall # echo 1 >> /sys/kernel/debug/tracing/events/probe_libc/enable # perf record -e probe_libc:syscall whatever kills the uprobe. Along the way he found some other minor bugs and clean ups that he fixed up making it a total of 4 patches. Doing unrelated work, I found that the reading of the ftrace trace file disables all function tracer callbacks. This was fine when ftrace was the only user, but now that it's used by perf and kprobes, this is a bug where reading trace can disable kprobes and perf. A very unexpected side effect and should be fixed" * tag 'trace-fixes-v3.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Remove ftrace_stop/start() from reading the trace file tracing/uprobes: Fix the usage of uprobe_buffer_enable() in probe_event_enable() tracing/uprobes: Kill the bogus UPROBE_HANDLER_REMOVE code in uprobe_dispatcher() uprobes: Change unregister/apply to WARN() if uprobe/consumer is gone tracing/uprobes: Revert "Support mix of ftrace and perf"
2014-07-02perf: Do not allow optimized switch for non-cloned eventsJiri Olsa1-1/+1
The context check in perf_event_context_sched_out allows non-cloned context to be part of the optimized schedule out switch. This could move non-cloned context into another workload child. Once this child exits, the context is closed and leaves all original (parent) events in closed state. Any other new cloned event will have closed state and not measure anything. And probably causing other odd bugs. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1403598026-2310-2-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-30uprobes: Change unregister/apply to WARN() if uprobe/consumer is goneOleg Nesterov1-3/+3
Add WARN_ON's into uprobe_unregister() and uprobe_apply() to ensure that nobody tries to play with the dead uprobe/consumer. This helps to catch the bugs like the one fixed by the previous patch. In the longer term we should fix this poorly designed interface. uprobe_register() should return "struct uprobe *" which should be passed to apply/unregister. Plus other semantic changes, see the changelog in commit 41ccba029e94. Link: http://lkml.kernel.org/p/20140627170140.GA18322@redhat.com Acked-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-14Merge branch 'perf/core' into perf/urgent, to pick up the latest fixesIngo Molnar1-4/+33
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-12Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2-35/+60
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more perf updates from Ingo Molnar: "A second round of perf updates: - wide reaching kprobes sanitization and robustization, with the hope of fixing all 'probe this function crashes the kernel' bugs, by Masami Hiramatsu. - uprobes updates from Oleg Nesterov: tmpfs support, corner case fixes and robustization work. - perf tooling updates and fixes from Jiri Olsa, Namhyung Ki, Arnaldo et al: * Add support to accumulate hist periods (Namhyung Kim) * various fixes, refactorings and enhancements" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits) perf: Differentiate exec() and non-exec() comm events perf: Fix perf_event_comm() vs. exec() assumption uprobes/x86: Rename arch_uprobe->def to ->defparam, minor comment updates perf/documentation: Add description for conditional branch filter perf/x86: Add conditional branch filtering support perf/tool: Add conditional branch filter 'cond' to perf record perf: Add new conditional branch filter 'PERF_SAMPLE_BRANCH_COND' uprobes: Teach copy_insn() to support tmpfs uprobes: Shift ->readpage check from __copy_insn() to uprobe_register() perf/x86: Use common PMU interrupt disabled code perf/ARM: Use common PMU interrupt disabled code perf: Disable sampled events if no PMU interrupt perf: Fix use after free in perf_remove_from_context() perf tools: Fix 'make help' message error perf record: Fix poll return value propagation perf tools: Move elide bool into perf_hpp_fmt struct perf tools: Remove elide setup for SORT_MODE__MEMORY mode perf tools: Fix "==" into "=" in ui_browser__warning assignment perf tools: Allow overriding sysfs and proc finding with env var perf tools: Consider header files outside perf directory in tags target ...
2014-06-09Merge branch 'for-3.16' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "A lot of activities on cgroup side. Heavy restructuring including locking simplification took place to improve the code base and enable implementation of the unified hierarchy, which currently exists behind a __DEVEL__ mount option. The core support is mostly complete but individual controllers need further work. To explain the design and rationales of the the unified hierarchy Documentation/cgroups/unified-hierarchy.txt is added. Another notable change is css (cgroup_subsys_state - what each controller uses to identify and interact with a cgroup) iteration update. This is part of continuing updates on css object lifetime and visibility. cgroup started with reference count draining on removal way back and is now reaching a point where csses behave and are iterated like normal refcnted objects albeit with some complexities to allow distinguishing the state where they're being deleted. The css iteration update isn't taken advantage of yet but is planned to be used to simplify memcg significantly" * 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (77 commits) cgroup: disallow disabled controllers on the default hierarchy cgroup: don't destroy the default root cgroup: disallow debug controller on the default hierarchy cgroup: clean up MAINTAINERS entries cgroup: implement css_tryget() device_cgroup: use css_has_online_children() instead of has_children() cgroup: convert cgroup_has_live_children() into css_has_online_children() cgroup: use CSS_ONLINE instead of CGRP_DEAD cgroup: iterate cgroup_subsys_states directly cgroup: introduce CSS_RELEASED and reduce css iteration fallback window cgroup: move cgroup->serial_nr into cgroup_subsys_state cgroup: link all cgroup_subsys_states in their sibling lists cgroup: move cgroup->sibling and ->children into cgroup_subsys_state cgroup: remove cgroup->parent device_cgroup: remove direct access to cgroup->children memcg: update memcg_has_children() to use css_next_child() memcg: remove tasks/children test from mem_cgroup_force_empty() cgroup: remove css_parent() cgroup: skip refcnting on normal root csses and cgrp_dfl_root self css cgroup: use cgroup->self.refcnt for cgroup refcnting ...
2014-06-09Revert "perf: Disable PERF_RECORD_MMAP2 support"Don Zickus1-4/+0
This reverts commit 3090ffb5a2515990182f3f55b0688a7817325488. Re-enable the mmap2 interface as we will have a user soon. Since things have changed since perf disabled mmap2, small tweaks to the revert had to be done: o commit 9d4ecc88 forced (n!=8) to become (n<7) o a new libunwind test needed updating to use mmap2 interface Signed-off-by: Don Zickus <dzickus@redhat.com> Link: http://lkml.kernel.org/r/1401461382-209586-1-git-send-email-dzickus@redhat.com Signed-off-by: Jiri Olsa <jolsa@kernel.org>
2014-06-09perf: Pass protection and flags bits through mmap2 interfacePeter Zijlstra1-0/+33
The mmap2 interface was missing the protection and flags bits needed to accurately determine if a mmap memory area was shared or private and if it was readable or not. Signed-off-by: Peter Zijlstra <peterz@infradead.org> [tweaked patch to compile and wrote changelog] Signed-off-by: Don Zickus <dzickus@redhat.com> Link: http://lkml.kernel.org/r/1400526833-141779-2-git-send-email-dzickus@redhat.com Signed-off-by: Jiri Olsa <jolsa@kernel.org>
2014-06-06perf: Differentiate exec() and non-exec() comm eventsAdrian Hunter1-2/+2
perf tools like 'perf report' can aggregate samples by comm strings, which generally works. However, there are other potential use-cases. For example, to pair up 'calls' with 'returns' accurately (from branch events like Intel BTS) it is necessary to identify whether the process has exec'd. Although a comm event is generated when an 'exec' happens it is also generated whenever the comm string is changed on a whim (e.g. by prctl PR_SET_NAME). This patch adds a flag to the comm event to differentiate one case from the other. In order to determine whether the kernel supports the new flag, a selection bit named 'exec' is added to struct perf_event_attr. The bit does nothing but will cause perf_event_open() to fail if the bit is set on kernels that do not have it defined. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/537D9EBE.7030806@intel.com Cc: Paul Mackerras <paulus@samba.org> Cc: Dave Jones <davej@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-06Merge branch 'perf/urgent' into perf/core, to resolve conflict and to ↵Ingo Molnar1-73/+80
prepare for new patches Conflicts: arch/x86/kernel/traps.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-06perf: Fix perf_event_comm() vs. exec() assumptionPeter Zijlstra1-12/+16
perf_event_comm() assumes that set_task_comm() is only called on exec(), and in particular that its only called on current. Neither are true, as Dave reported a WARN triggered by set_task_comm() being called on !current. Separate the exec() hook from the comm hook. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20140521153219.GH5226@laptop.programming.kicks-ass.net [ Build fix. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-05Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm into nextLinus Torvalds1-8/+17
Pull ARM updates from Russell King: - Major clean-up of the L2 cache support code. The existing mess was becoming rather unmaintainable through all the additions that others have done over time. This turns it into a much nicer structure, and implements a few performance improvements as well. - Clean up some of the CP15 control register tweaks for alignment support, moving some code and data into alignment.c - DMA properties for ARM, from Santosh and reviewed by DT people. This adds DT properties to specify bus translations we can't discover automatically, and to indicate whether devices are coherent. - Hibernation support for ARM - Make ftrace work with read-only text in modules - add suspend support for PJ4B CPUs - rework interrupt masking for undefined instruction handling, which allows us to enable interrupts earlier in the handling of these exceptions. - support for big endian page tables - fix stacktrace support to exclude stacktrace functions from the trace, and add save_stack_trace_regs() implementation so that kprobes can record stack traces. - Add support for the Cortex-A17 CPU. - Remove last vestiges of ARM710 support. - Removal of ARM "meminfo" structure, finally converting us solely to memblock to handle the early memory initialisation. * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (142 commits) ARM: ensure C page table setup code follows assembly code (part II) ARM: ensure C page table setup code follows assembly code ARM: consolidate last remaining open-coded alignment trap enable ARM: remove global cr_no_alignment ARM: remove CPU_CP15 conditional from alignment.c ARM: remove unused adjust_cr() function ARM: move "noalign" command line option to alignment.c ARM: provide common method to clear bits in CPU control register ARM: 8025/1: Get rid of meminfo ARM: 8060/1: mm: allow sub-architectures to override PCI I/O memory type ARM: 8066/1: correction for ARM patch 8031/2 ARM: 8049/1: ftrace/add save_stack_trace_regs() implementation ARM: 8065/1: remove last use of CONFIG_CPU_ARM710 ARM: 8062/1: Modify ldrt fixup handler to re-execute the userspace instruction ARM: 8047/1: rwsem: use asm-generic rwsem implementation ARM: l2c: trial at enabling some Cortex-A9 optimisations ARM: l2c: add warnings for stuff modifying aux_ctrl register values ARM: l2c: print a warning with L2C-310 caches if the cache size is modified ARM: l2c: remove old .set_debug method ARM: l2c: kill L2X0_AUX_CTRL_MASK before anyone else makes use of this ...
2014-06-05uprobes: Teach copy_insn() to support tmpfsOleg Nesterov1-5/+10
tmpfs is widely used but as Denys reports shmem_aops doesn't have ->readpage() and thus you can't probe a binary on this filesystem. As Hugh suggested we can use shmem_read_mapping_page() in this case, just we need to check shmem_mapping() if ->readpage == NULL. Reported-by: Denys Vlasenko <dvlasenk@redhat.com> Suggested-by: Hugh Dickins <hughd@google.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140519184136.GB6750@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-05uprobes: Shift ->readpage check from __copy_insn() to uprobe_register()Oleg Nesterov1-3/+3
copy_insn() fails with -EIO if ->readpage == NULL, but this error is not propagated unless uprobe_register() path finds ->mm which already mmaps this file. In this case (say) "perf record" does not actually install the probe, but the user can't know about this. Move this check into uprobe_register() so that this problem can be detected earlier and reported to user. Note: this is still not perfect, - copy_insn() and arch_uprobe_analyze_insn() should be called by uprobe_register() but this is not simple, we need vm_file for read_mapping_page() (although perhaps we can pass NULL), and we need ->mm for is_64bit_mm() (although this logic is broken anyway). - uprobe_register() should be called by create_trace_uprobe(), not by probe_event_enable(), so that an error can be detected at "perf probe -x" time. This also needs more changes in the core uprobe code, uprobe register/unregister interface was poorly designed from the very beginning. Reported-by: Denys Vlasenko <dvlasenk@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140519184054.GA6750@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-05perf: Disable sampled events if no PMU interruptVince Weaver1-0/+7
Add common code to generate -ENOTSUPP at event creation time if an architecture attempts to create a sampled event and PERF_PMU_NO_INTERRUPT is set. This adds a new pmu->capabilities flag. Initially we only support PERF_PMU_NO_INTERRUPT (to indicate a PMU has no support for generating hardware interrupts) but there are other capabilities that can be added later. Signed-off-by: Vince Weaver <vincent.weaver@maine.edu> Acked-by: Will Deacon <will.deacon@arm.com> [peterz: rename to PERF_PMU_CAP_* and moved the pmu::capabilities word into a hole] Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1405161708060.11099@vincent-weaver-1.umelst.maine.edu Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-05perf: Fix use after free in perf_remove_from_context()Peter Zijlstra1-2/+2
While that mutex should guard the elements, it doesn't guard against the use-after-free that's from list_for_each_entry_rcu(). __perf_event_exit_task() can actually free the event. And because list addition/deletion is guarded by both ctx->mutex and ctx->lock, holding ctx->mutex is sufficient for reading the list, so we don't actually need the rcu list iteration. Fixes: 3a497f48637e ("perf: Simplify perf_event_exit_task_context()") Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Dave Jones <davej@redhat.com> Cc: acme@ghostprotocols.net Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140529170024.GA2315@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-05Merge branch 'perf/uprobes' into perf/coreIngo Molnar1-13/+22
These bits from Oleg are fully cooked, ship them to Linus. Signed-off-by: Ingo Molnar <mingo@kernel.org>