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2009-09-21perf: Do the big rename: Performance Counters -> Performance EventsIngo Molnar
Bye-bye Performance Counters, welcome Performance Events! In the past few months the perfcounters subsystem has grown out its initial role of counting hardware events, and has become (and is becoming) a much broader generic event enumeration, reporting, logging, monitoring, analysis facility. Naming its core object 'perf_counter' and naming the subsystem 'perfcounters' has become more and more of a misnomer. With pending code like hw-breakpoints support the 'counter' name is less and less appropriate. All in one, we've decided to rename the subsystem to 'performance events' and to propagate this rename through all fields, variables and API names. (in an ABI compatible fashion) The word 'event' is also a bit shorter than 'counter' - which makes it slightly more convenient to write/handle as well. Thanks goes to Stephane Eranian who first observed this misnomer and suggested a rename. User-space tooling and ABI compatibility is not affected - this patch should be function-invariant. (Also, defconfigs were not touched to keep the size down.) This patch has been generated via the following script: FILES=$(find * -type f | grep -vE 'oprofile|[^K]config') sed -i \ -e 's/PERF_EVENT_/PERF_RECORD_/g' \ -e 's/PERF_COUNTER/PERF_EVENT/g' \ -e 's/perf_counter/perf_event/g' \ -e 's/nb_counters/nb_events/g' \ -e 's/swcounter/swevent/g' \ -e 's/tpcounter_event/tp_event/g' \ $FILES for N in $(find . -name perf_counter.[ch]); do M=$(echo $N | sed 's/perf_counter/perf_event/g') mv $N $M done FILES=$(find . -name perf_event.*) sed -i \ -e 's/COUNTER_MASK/REG_MASK/g' \ -e 's/COUNTER/EVENT/g' \ -e 's/\<event\>/event_id/g' \ -e 's/counter/event/g' \ -e 's/Counter/Event/g' \ $FILES ... to keep it as correct as possible. This script can also be used by anyone who has pending perfcounters patches - it converts a Linux kernel tree over to the new naming. We tried to time this change to the point in time where the amount of pending patches is the smallest: the end of the merge window. Namespace clashes were fixed up in a preparatory patch - and some stylistic fallout will be fixed up in a subsequent patch. ( NOTE: 'counters' are still the proper terminology when we deal with hardware registers - and these sed scripts are a bit over-eager in renaming them. I've undone some of that, but in case there's something left where 'counter' would be better than 'event' we can undo that on an individual basis instead of touching an otherwise nicely automated patch. ) Suggested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21perf_counter: Rename 'event' to event_id/hw_eventIngo Molnar
In preparation to the renames, to avoid a namespace clash. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21perf_counter: Rename list_entry -> group_entry, counter_list -> group_listIngo Molnar
This is in preparation of the big rename, but also makes sense in a standalone way: 'list_entry' is a bad name as we already have a list_entry() in list.h. Also, the 'counter list' is too vague, it doesnt tell us the purpose of that list. Clarify these names to show that it's all about the group hiearchy. Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-19perf_counter: Fix perf_copy_attr() pointer arithmeticIan Schram
There is still some weird code in per_copy_attr(). Which supposedly checks that all bytes trailing a struct are zero. It doesn't seem to get pointer arithmetic right. Since it increments an iterating pointer by sizeof(unsigned long) rather than 1. Signed-off-by: Ian Schram <ischram@telenet.be> [ v2: clean up the messy PTR_ALIGN logic as well. ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: <stable@kernel.org> # for v2.6.31.x LKML-Reference: <4AB3DEE2.3030600@telenet.be> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-19perf: Add a timestamp to fork eventsArjan van de Ven
perf timechart needs to know when a process forked, in order to be able to visualize properly when tasks start. This patch adds a time field to the event structure, and fills it in appropriately. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20090912130341.51ad2de2@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-19Merge branch 'linus' into perfcounters/coreIngo Molnar
Merge reason: Bring in tracing changes we depend on. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-18sched_clock: Make it NMI safePeter Zijlstra
Arjan complained about the suckyness of TSC on modern machines, and asked if we could do something about that for PERF_SAMPLE_TIME. Make cpu_clock() NMI safe by removing the spinlock and using cmpxchg. This also makes it smaller and more robust. Affects architectures that use HAVE_UNSTABLE_SCHED_CLOCK, i.e. IA64 and x86. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-18perf_counter: Fix up swcounter throttlingPeter Zijlstra
/me dons the brown paper bag. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-18x86, perf_counter, bts: Optimize BTS overflow handlingMarkus Metzger
Draining the BTS buffer on a buffer overflow interrupt takes too long resulting in a kernel lockup when tracing the kernel. Restructure perf_counter sampling into sample creation and sample output. Prepare a single reference sample for BTS sampling and update the from and to address fields when draining the BTS buffer. Drain the entire BTS buffer between a single perf_output_begin() / perf_output_end() pair. Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090915130023.A16204@sedona.ch.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-17perf_counter: Allow for a wakeup watermarkPeter Zijlstra
Currently we wake the mmap() consumer once every PAGE_SIZE of data and/or once event wakeup_events when specified. For high speed sampling this results in too many wakeups wrt. the buffer size, hence change this. We move the default wakeup limit to 1/4-th the buffer size, and provide for means to manually specify this limit. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-17perf_counter: Do not throttle single swcounter eventsPeter Zijlstra
We can have swcounter events that contribute more than a single count per event, when used with a non-zero period, those can generate multiple events, which is when we need throttling. However, swcounter that contribute only a single count per event can only come as fast as we can run code, hence don't throttle them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-15Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits) powerpc64: convert to dynamic percpu allocator sparc64: use embedding percpu first chunk allocator percpu: kill lpage first chunk allocator x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA percpu: update embedding first chunk allocator to handle sparse units percpu: use group information to allocate vmap areas sparsely vmalloc: implement pcpu_get_vm_areas() vmalloc: separate out insert_vmalloc_vm() percpu: add chunk->base_addr percpu: add pcpu_unit_offsets[] percpu: introduce pcpu_alloc_info and pcpu_group_info percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward percpu: add @align to pcpu_fc_alloc_fn_t percpu: make @dyn_size mandatory for pcpu_setup_first_chunk() percpu: drop @static_size from first chunk allocators percpu: generalize first chunk allocator selection percpu: build first chunk allocators selectively percpu: rename 4k first chunk allocator to page percpu: improve boot messages percpu: fix pcpu_reclaim() locking ... Fix trivial conflict as by Tejun Heo in kernel/sched.c
2009-09-15Merge branch 'perfcounters-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf_counter: Fix buffer overflow in perf_copy_attr()
2009-09-15perf_counter: Fix buffer overflow in perf_copy_attr()Xiao Guangrong
If we pass a big size data over perf_counter_open() syscall, the kernel will copy this data to a small buffer, it will cause kernel crash. This bug makes the kernel unsafe and non-root local user can trigger it. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul Mackerras <paulus@samba.org> Cc: <stable@kernel.org> LKML-Reference: <4AAF37D4.5010706@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-13perf_counter: Allow mmap if paranoid checks are turned offIngo Molnar
Before: $ perf sched record -f sleep 1 Error: failed to mmap with 1 (Operation not permitted) After: $ perf sched record -f sleep 1 [ perf record: Captured and wrote 0.095 MB perf.data (~4161 samples) ] Note, this is only allowed if perfcounter_paranoid is set to the most permissive (non-default) value of -1. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-03perf_counter: Fix output-sharing error pathIngo Molnar
We forget to release the fd in the PERF_FLAG_FD_OUTPUT error path. Reorganize the error flow here to be a clean fall-through logic. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-02perf_counter: Introduce new (non-)paranoia level to allow raw tracepoint accessIngo Molnar
I want to sample inherited tracepoint workloads as a normal user and the CAP_SYS_ADMIN check prevents me from doing that right now. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-02Merge branch 'perfcounters/urgent' into perfcounters/coreIngo Molnar
Merge reason: We are going to modify a place modified by perfcounters/urgent. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-29perf_counter: Fix /0 bug in swcountersPeter Zijlstra
We have a race in the swcounter stuff where we can start counting a counter that has never been enabled, this leads to a /0 situation. The below avoids the /0 but doesn't close the race, this would need a new counter state. The race is due to perf_swcounter_is_counting() which cannot discern between disabled due to scheduled out, and disabled for any other reason. Such a crash has been seen by Ingo: [ 967.092372] divide error: 0000 [#1] SMP [ 967.096499] last sysfs file: /sys/devices/system/cpu/cpu15/cache/index2/shared_cpu_map [ 967.104846] CPU 5 [ 967.106965] Modules linked in: [ 967.110169] Pid: 3351, comm: hackbench Not tainted 2.6.31-rc8-tip-01158-gd940a54-dirty #1568 X8DTN [ 967.119456] RIP: 0010:[<ffffffff810c0aba>] [<ffffffff810c0aba>] perf_swcounter_ctx_event+0x127/0x1af [ 967.129137] RSP: 0018:ffff8801a95abd70 EFLAGS: 00010046 [ 967.134699] RAX: 0000000000000002 RBX: ffff8801bd645c00 RCX: 0000000000000002 [ 967.142162] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8801bd645d40 [ 967.149584] RBP: ffff8801a95abdb0 R08: 0000000000000001 R09: ffff8801a95abe00 [ 967.157042] R10: 0000000000000037 R11: ffff8801aa1245f8 R12: ffff8801a95abe00 [ 967.164481] R13: ffff8801a95abe00 R14: ffff8801aa1c0e78 R15: 0000000000000001 [ 967.171953] FS: 0000000000000000(0000) GS:ffffc90000a00000(0063) knlGS:00000000f7f486c0 [ 967.180406] CS: 0010 DS: 002b ES: 002b CR0: 000000008005003b [ 967.186374] CR2: 000000004822c0ac CR3: 00000001b19a2000 CR4: 00000000000006e0 [ 967.193770] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 967.201224] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 967.208692] Process hackbench (pid: 3351, threadinfo ffff8801a95aa000, task ffff8801a96b0000) [ 967.217607] Stack: [ 967.219711] 0000000000000000 0000000000000037 0000000200000001 ffffc90000a1107c [ 967.227296] <0> ffff8801a95abe00 0000000000000001 0000000000000001 0000000000000037 [ 967.235333] <0> ffff8801a95abdf0 ffffffff810c0c20 0000000200a14f30 ffff8801a95abe40 [ 967.243532] Call Trace: [ 967.246103] [<ffffffff810c0c20>] do_perf_swcounter_event+0xde/0xec [ 967.252635] [<ffffffff810c0ca7>] perf_tpcounter_event+0x79/0x7b [ 967.258957] [<ffffffff81037f73>] ftrace_profile_sched_switch+0xc0/0xcb [ 967.265791] [<ffffffff8155f22d>] schedule+0x429/0x4c4 [ 967.271156] [<ffffffff8100c01e>] int_careful+0xd/0x14 Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1251472247.17617.74.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-28perf_counters: Increase paranoia levelIngo Molnar
Per-cpu counters are an ASLR information leak as they show the execution other tasks do. Increase the paranoia level to 1, which disallows per-cpu counters. (they still allow counting/profiling of own tasks - and admin can profile everything.) Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-25perf_counter: Allow sharing of output channelsPeter Zijlstra
Provide the ability to configure a counter to send its output to another (already existing) counter's output stream. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: stephane eranian <eranian@googlemail.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20090819092023.980284148@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-25perf_counter: Start counting time enabled when group leader gets enabledPaul Mackerras
Currently, if a group is created where the group leader is initially disabled but a non-leader member is initially enabled, and then the leader is subsequently enabled some time later, the time_enabled for the non-leader member will reflect the whole time since it was created, not just the time since the leader was enabled. This is incorrect, because all of the members are effectively disabled while the leader is disabled, since none of the members can go on the PMU if the leader can't. Thus we have to update the ->tstamp_enabled for all the enabled group members when a group leader is enabled, so that the time_enabled computation only counts the time since the leader was enabled. Similarly, when disabling a group leader we have to update the time_enabled and time_running for all of the group members. Also, in update_counter_times, we have to treat a counter whose group leader is disabled as being disabled. Reported-by: Stephane Eranian <eranian@googlemail.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> LKML-Reference: <19091.29664.342227.445006@drongo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-21perf_counter: Fix typo in read() output generationPeter Zijlstra
When you iterate a list, using the iterator is useful. Before: ID: 5 ID: 5 ID: 5 ID: 5 EVNT: 0x40088b scale: nan ID: 5 CNT: 1006252 ID: 6 CNT: 1011090 ID: 7 CNT: 1011196 ID: 8 CNT: 1011095 EVNT: 0x40088c scale: 1.000000 ID: 5 CNT: 2003065 ID: 6 CNT: 2011671 ID: 7 CNT: 2012620 ID: 8 CNT: 2013479 EVNT: 0x40088c scale: 1.000000 ID: 5 CNT: 3002390 ID: 6 CNT: 3015996 ID: 7 CNT: 3018019 ID: 8 CNT: 3020006 EVNT: 0x40088b scale: 1.000000 ID: 5 CNT: 4002406 ID: 6 CNT: 4021120 ID: 7 CNT: 4024241 ID: 8 CNT: 4027059 After: ID: 1 ID: 2 ID: 3 ID: 4 EVNT: 0x400889 scale: nan ID: 1 CNT: 1005270 ID: 2 CNT: 1009833 ID: 3 CNT: 1010065 ID: 4 CNT: 1010088 EVNT: 0x400898 scale: nan ID: 1 CNT: 2001531 ID: 2 CNT: 2022309 ID: 3 CNT: 2022470 ID: 4 CNT: 2022627 EVNT: 0x400888 scale: 0.489467 ID: 1 CNT: 3001261 ID: 2 CNT: 3027088 ID: 3 CNT: 3027941 ID: 4 CNT: 3028762 Reported-by: stephane eranian <eranian@googlemail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey J Ashford <cjashfor@us.ibm.com> Cc: perfmon2-devel <perfmon2-devel@lists.sourceforge.net> LKML-Reference: <1250867976.7538.73.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18perf_counter: Fix the PARISC buildIngo Molnar
PARISC does not build: /home/mingo/tip/kernel/perf_counter.c: In function 'perf_counter_index': /home/mingo/tip/kernel/perf_counter.c:2016: error: 'PERF_COUNTER_INDEX_OFFSET' undeclared (first use in this function) /home/mingo/tip/kernel/perf_counter.c:2016: error: (Each undeclared identifier is reported only once /home/mingo/tip/kernel/perf_counter.c:2016: error: for each function it appears in.) As PERF_COUNTER_INDEX_OFFSET is not defined. Now, we could define it in the architecture - but lets also provide a core default of 0 (which happens to be what all but one architecture uses at the moment). Architectures that need a different index offset should set this value in their asm/perf_counter.h files. Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Helge Deller <deller@gmx.de> Cc: linux-parisc@vger.kernel.org Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-17perf_counter: Check task on counter read IPIPaul Mackerras
In general, code in perf_counter.c that is called through an IPI checks, for per-task counters, that the counter's task is still the current task. This is to handle the race condition where the cpu switches from the task we want to another task in the interval between sending the IPI and the IPI arriving and being handled on the target CPU. For some reason, __perf_counter_read is missing this check, yet there is no reason why the race condition can't occur. This adds a check that the current task is the one we want. If it isn't, we just return. In that case the counter->count value should be up to date, since it will have been updated when the counter was scheduled out, which must have happened since the IPI was sent. I don't have an example of an actual failure due to this race, but it seems obvious that it could occur and we need to guard against it. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <19076.63614.277861.368125@drongo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-14Merge branch 'percpu-for-linus' into percpu-for-nextTejun Heo
Conflicts: arch/sparc/kernel/smp_64.c arch/x86/kernel/cpu/perf_counter.c arch/x86/kernel/setup_percpu.c drivers/cpufreq/cpufreq_ondemand.c mm/percpu.c Conflicts in core and arch percpu codes are mostly from commit ed78e1e078dd44249f88b1dd8c76dafb39567161 which substituted many num_possible_cpus() with nr_cpu_ids. As for-next branch has moved all the first chunk allocators into mm/percpu.c, the changes are moved from arch code to mm/percpu.c. Signed-off-by: Tejun Heo <tj@kernel.org>
2009-08-13perf_counter: Report the cloning task as parent on perf_counter_fork()Peter Zijlstra
A bug in (9f498cc: perf_counter: Full task tracing) makes profiling multi-threaded apps it go belly up. [ output as: (PID:TID):(PPID:PTID) ] # ./perf report -D | grep FORK 0x4b0 [0x18]: PERF_EVENT_FORK: (3237:3237):(3236:3236) 0xa10 [0x18]: PERF_EVENT_FORK: (3237:3238):(3236:3236) 0xa70 [0x18]: PERF_EVENT_FORK: (3237:3239):(3236:3236) 0xad0 [0x18]: PERF_EVENT_FORK: (3237:3240):(3236:3236) 0xb18 [0x18]: PERF_EVENT_FORK: (3237:3241):(3236:3236) Shows us that the test (27d028d perf report: Update for the new FORK/EXIT events) in builtin-report.c: /* * A thread clone will have the same PID for both * parent and child. */ if (thread == parent) return 0; Will clearly fail. The problem is that perf_counter_fork() reports the actual parent, instead of the cloning thread. Fixing that (with the below patch), yields: # ./perf report -D | grep FORK 0x4c8 [0x18]: PERF_EVENT_FORK: (1590:1590):(1589:1589) 0xbd8 [0x18]: PERF_EVENT_FORK: (1590:1591):(1590:1590) 0xc80 [0x18]: PERF_EVENT_FORK: (1590:1592):(1590:1590) 0x3338 [0x18]: PERF_EVENT_FORK: (1590:1593):(1590:1590) 0x66b0 [0x18]: PERF_EVENT_FORK: (1590:1594):(1590:1590) Which both makes more sense and doesn't confuse perf report anymore. Reported-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: paulus@samba.org Cc: Anton Blanchard <anton@samba.org> Cc: Arjan van de Ven <arjan@infradead.org> LKML-Reference: <1250172882.5241.62.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-13perf_counter: Fix an ipi-deadlockPeter Zijlstra
perf_pending_counter() is called from IRQ context and will call perf_counter_disable(), however perf_counter_disable() uses smp_call_function_single() which doesn't fancy being used with IRQs disabled due to IPI deadlocks. Fix this by making it use the local __perf_counter_disable() call and teaching the counter_sched_out() code about pending disables as well. This should cover the case where a counter migrates before the pending queue gets processed. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey J Ashford <cjashfor@us.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: stephane eranian <eranian@googlemail.com> LKML-Reference: <20090813103655.244097721@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-13perf: Rework/fix the whole read vs group stuffPeter Zijlstra
Replace PERF_SAMPLE_GROUP with PERF_SAMPLE_READ and introduce PERF_FORMAT_GROUP to deal with group reads in a more generic way. This allows you to get group reads out of read() as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey J Ashford <cjashfor@us.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: stephane eranian <eranian@googlemail.com> LKML-Reference: <20090813103655.117411814@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-13perf_counter: Fix swcounter context invariancePeter Zijlstra
perf_swcounter_is_counting() uses a lock, which means we cannot use swcounters from NMI or when holding that particular lock, this is unintended. The below removes the lock, this opens up race window, but not worse than the swcounters already experience due to RCU traversal of the context in perf_swcounter_ctx_event(). This also fixes the hard lockups while opening a lockdep tracepoint counter. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: stephane eranian <eranian@googlemail.com> Cc: Corey J Ashford <cjashfor@us.ibm.com> LKML-Reference: <1250149915.10001.66.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-13perf_counter: Provide hw_perf_counter_setup_online() APIsIngo Molnar
Provide weak aliases for hw_perf_counter_setup_online(). This is used by the BTS patches (for v2.6.32), but it interacts with fixes so propagate this upstream. (it has no effect as of yet) Also export perf_counter_output() to architecture code. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-10perf_counter: Require CAP_SYS_ADMIN for raw tracepoint dataPeter Zijlstra
Raw tracepoint data contains various kernel internals and data from other users, so restrict this to CAP_SYS_ADMIN. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1249896452.17467.75.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-10perf_counter: Correct PERF_SAMPLE_RAW outputPeter Zijlstra
PERF_SAMPLE_* output switches should unconditionally output the correct format, as they are the only way to unambiguously parse the PERF_EVENT_SAMPLE data. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1249896447.17467.74.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-09perf_counter: Fix a race on perf_counter_ctxPeter Zijlstra
While extending perfcounters with BTS hw-tracing, Markus Metzger managed to trigger this warning: [ 995.557128] WARNING: at kernel/perf_counter.c:1191 __perf_counter_task_sched_out+0x48/0x6b() triggers because commit 9f498cc5be7e013d8d6e4c616980ed0ffc8680d2 (perf_counter: Full task tracing) removed clearing of tsk->perf_counter_ctxp out from under ctx->lock which introduced a race (against perf_lock_task_context). Move it back and deal with the exit notification by explicitly passing along the former task context. Reported-by: Markus T Metzger <markus.t.metzger@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1249667341.17467.5.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-09perf_counter: Fix tracepoint sampling to be part of generic samplingFrederic Weisbecker
Based on Peter's comments, make tracepoint sampling generic just like all the other sampling bits are. This is a rename with no code changes: - PERF_SAMPLE_TP_RECORD to PERF_SAMPLE_RAW - struct perf_tracepoint_record to perf_raw_record We want the system in place that transport tracepoints raw samples events into the perf ring buffer to be generalized and usable by any type of counter. Reported-by; Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1249698400-5441-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-09perf_counter: Work around gcc warning by initializing tracepoint record ↵Frederic Weisbecker
unconditionally Despite that the tracepoint record is always present when the PERF_SAMPLE_TP_RECORD flag is set, gcc raises a warning, thinking it might not be initialized: kernel/perf_counter.c: In function ‘perf_counter_output’: kernel/perf_counter.c:2650: warning: ‘tp’ may be used uninitialized in this function Then, initialize it to NULL and always check if it's not NULL before dereference it. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1249698400-5441-2-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-09perf_counter: Fix software counters for fast moving event sourcesPeter Zijlstra
Reimplement the software counters to deal with fast moving event sources (such as tracepoints). This means being able to generate multiple overflows from a single 'event' as well as support throttling. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-09perf_counter: Fix/complete ftrace event records samplingFrederic Weisbecker
This patch implements the kernel side support for ftrace event record sampling. A new counter sampling attribute is added: PERF_SAMPLE_TP_RECORD which requests ftrace events record sampling. In this case if a PERF_TYPE_TRACEPOINT counter is active and a tracepoint fires, we emit the tracepoint binary record to the perfcounter event buffer, as a sample. Result, after setting PERF_SAMPLE_TP_RECORD attribute from perf record: perf record -f -F 1 -a -e workqueue:workqueue_execution perf report -D 0x21e18 [0x48]: event: 9 . . ... raw event: size 72 bytes . 0000: 09 00 00 00 01 00 48 00 d0 c7 00 81 ff ff ff ff ......H........ . 0010: 0a 00 00 00 0a 00 00 00 21 00 00 00 00 00 00 00 ........!...... . 0020: 2b 00 01 02 0a 00 00 00 0a 00 00 00 65 76 65 6e +...........eve . 0030: 74 73 2f 31 00 00 00 00 00 00 00 00 0a 00 00 00 ts/1........... . 0040: e0 b1 31 81 ff ff ff ff ....... . 0x21e18 [0x48]: PERF_EVENT_SAMPLE (IP, 1): 10: 0xffffffff8100c7d0 period: 33 The raw ftrace binary record starts at offset 0020. Translation: struct trace_entry { type = 0x2b = 43; flags = 1; preempt_count = 2; pid = 0xa = 10; tgid = 0xa = 10; } thread_comm = "events/1" thread_pid = 0xa = 10; func = 0xffffffff8131b1e0 = flush_to_ldisc() What will come next? - Userspace support ('perf trace'), 'flight data recorder' mode for perf trace, etc. - The unconditional copy from the profiling callback brings some costs however if someone wants no such sampling to occur, and needs to be fixed in the future. For that we need to have an instant access to the perf counter attribute. This is a matter of a flag to add in the struct ftrace_event. - Take care of the events recursivity! Don't ever try to record a lock event for example, it seems some locking is used in the profiling fast path and lead to a tracing recursivity. That will be fixed using raw spinlock or recursivity protection. - [...] - Profit! :-) Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-09perf_counter, ftrace: Fix perf_counter integrationPeter Zijlstra
Adds possible second part to the assign argument of TP_EVENT(). TP_perf_assign( __perf_count(foo); __perf_addr(bar); ) Which, when specified make the swcounter increment with @foo instead of the usual 1, and report @bar for PERF_SAMPLE_ADDR (data address associated with the event) when this triggers a counter overflow. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-06perf_counter: Fix double list iteration in per task precise statsPeter Zijlstra
Brice Goglin reported this crash with per task precise stats: > I finally managed to test the threaded perfcounter statistics (thanks a > lot for implementing it). I am running 2.6.31-rc5 (with the AMD > magny-cours patches but I don't think they matter here). I am trying to > measure local/remote memory accesses per thread during the well-known > stream benchmark. It's compiled with OpenMP using 16 threads on a > quad-socket quad-core barcelona machine. > > Command line is: > /mnt/scratch/bgoglin/cpunode/linux-2.6.31/tools/perf/perf record -f -s > -e r1000001e0 -e r1000002e0 -e r1000004e0 -e r1000008e0 ./stream > > It seems to work fine with a single -e <counter> on the command line > while it crashes when there are at least 2 of them. > It seems to work fine without -s as well. A silly copy-paste resulted in a messed up iteration which would cause the OOPS. Reported-by: Brice Goglin <Brice.Goglin@inria.fr> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Brice Goglin <Brice.Goglin@inria.fr> LKML-Reference: <1249574786.32113.550.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-02perf_counter: Full task tracingPeter Zijlstra
In order to be able to distinguish between no samples due to inactivity and no samples due to task ended, Arjan asked for PERF_EVENT_EXIT events. This is useful to the boot delay instrumentation (bootchart) app. This patch changes the PERF_EVENT_FORK to be emitted on every clone, and adds PERF_EVENT_EXIT to be emitted on task exit, after the task's counters have been closed. This task tracing is controlled through: attr.comm || attr.mmap and through the new attr.task field. Suggested-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> [ cleaned up perf_counter.h a bit ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-02perf_counter: Collapse inherit on read()Peter Zijlstra
Currently the counter value returned by read() is the value of the parent counter, to which child counters are only fed back on child exit. Thus read() can return rather erratic (and meaningless) numbers depending on the state of the child processes. Change this by always iterating the full child hierarchy on read() and sum all counters. Suggested-by: Corey Ashford <cjashfor@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-22Merge branch 'perf-counters-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-perf * 'perf-counters-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-perf: (31 commits) perf_counter tools: Give perf top inherit option perf_counter tools: Fix vmlinux symbol generation breakage perf_counter: Detect debugfs location perf_counter: Add tracepoint support to perf list, perf stat perf symbol: C++ demangling perf: avoid structure size confusion by using a fixed size perf_counter: Fix throttle/unthrottle event logging perf_counter: Improve perf stat and perf record option parsing perf_counter: PERF_SAMPLE_ID and inherited counters perf_counter: Plug more stack leaks perf: Fix stack data leak perf_counter: Remove unused variables perf_counter: Make call graph option consistent perf_counter: Add perf record option to log addresses perf_counter: Log vfork as a fork event perf_counter: Synthesize VDSO mmap event perf_counter: Make sure we dont leak kernel memory to userspace perf_counter tools: Fix index boundary check perf_counter: Fix the tracepoint channel to perfcounters perf_counter, x86: Extend perf_counter Pentium M support ...
2009-07-22perf: fix stack data leakArjan van de Ven
the "reserved" field was not initialized to zero, resulting in 4 bytes of stack data leaking to userspace.... Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-22perf_counter: Fix throttle/unthrottle event loggingAnton Blanchard
Right now we only print PERF_EVENT_THROTTLE + 1 (ie PERF_EVENT_UNTHROTTLE). Fix this to print both a throttle and unthrottle event. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090722130546.GE9029@kryten>
2009-07-22perf_counter: PERF_SAMPLE_ID and inherited countersPeter Zijlstra
Anton noted that for inherited counters the counter-id as provided by PERF_SAMPLE_ID isn't mappable to the id found through PERF_RECORD_ID because each inherited counter gets its own id. His suggestion was to always return the parent counter id, since that is the primary counter id as exposed. However, these inherited counters have a unique identifier so that events like PERF_EVENT_PERIOD and PERF_EVENT_THROTTLE can be specific about which counter gets modified, which is important when trying to normalize the sample streams. This patch removes PERF_EVENT_PERIOD in favour of PERF_SAMPLE_PERIOD, which is more useful anyway, since changing periods became a lot more common than initially thought -- rendering PERF_EVENT_PERIOD the less useful solution (also, PERF_SAMPLE_PERIOD reports the more accurate value, since it reports the value used to trigger the overflow, whereas PERF_EVENT_PERIOD simply reports the requested period changed, which might only take effect on the next cycle). This still leaves us PERF_EVENT_THROTTLE to consider, but since that _should_ be a rare occurrence, and linking it to a primary id is the most useful bit to diagnose the problem, we introduce a PERF_SAMPLE_STREAM_ID, for those few cases where the full reconstruction is important. [Does change the ABI a little, but I see no other way out] Suggested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1248095846.15751.8781.camel@twins>
2009-07-22perf_counter: Plug more stack leaksPeter Zijlstra
Per example of Arjan's patch, I went through and found a few more. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2009-07-22perf: Fix stack data leakArjan van de Ven
the "reserved" field was not initialized to zero, resulting in 4 bytes of stack data leaking to userspace.... Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2009-07-22Merge commit 'tip/perfcounters/core' into perf-counters-for-linusPeter Zijlstra
2009-07-18perf_counter: Make sure we dont leak kernel memory to userspaceAnton Blanchard
There are a few places we are leaking tiny amounts of kernel memory to userspace. This happens when writing out strings because we always align the end to 64 bits. To avoid this we should always use an appropriately sized temporary buffer and ensure it is zeroed. Since d_path assembles the string from the end of the buffer backwards, we need to add 64 bits after the buffer to allow for alignment. We also need to copy arch_vma_name to the temporary buffer, because if we use it directly we may end up copying to userspace a number of bytes after the end of the string constant. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090716104817.273972048@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>