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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>
2009-08-21perf_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>
2009-08-13perf_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>
2009-07-13perf_counter: Fix the tracepoint channel to perfcountersChris Wilson
Fix a missed rename in EVENT_PROFILE support so that it gets built and allows tracepoint tracing from the 'perf' tool. Fix a typo in the (never before built & enabled) portion in perf_counter.c as well, and update that code to the attr.config changes as well. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ben Gamari <bgamari.foss@gmail.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1246869094-21237-1-git-send-email-chris@chris-wilson.co.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-10perf_counter: Stop open coding unclone_ctxPeter Zijlstra
Instead of open coding the unclone context thingy, put it in a common function. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-06Fix virt_to_phys() warningsKevin Cernekee
These warnings were observed on MIPS32 using 2.6.31-rc1 and gcc-4.2.0: mm/page_alloc.c: In function 'alloc_pages_exact': mm/page_alloc.c:1986: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast drivers/usb/mon/mon_bin.c: In function 'mon_alloc_buff': drivers/usb/mon/mon_bin.c:1264: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [akpm@linux-foundation.org: fix kernel/perf_counter.c too] Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-30perf_counter: Provide a way to enable counters on execPaul Mackerras
This provides a way to mark a counter to be enabled on the next exec. This is useful for measuring the total activity of a program without including overhead from the process that launches it. This also changes the perf stat command to use this new facility. Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <19017.43927.838745.689203@cargo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-26perf_counter: Complete counter swapPeter Zijlstra
Complete the counter swap by indeed switching the times too and updating the userpage after modifying the counter values. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1246014623.31755.195.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-25perf_counter: Rework the sample ABIPeter Zijlstra
The PERF_EVENT_READ implementation made me realize we don't actually need the sample_type int the output sample, since we already have that in the perf_counter_attr information. Therefore, remove the PERF_EVENT_MISC_OVERFLOW bit and the event->type overloading, and imply put counter overflow samples in a PERF_EVENT_SAMPLE type. This also fixes the issue that event->type was only 32-bit and sample_type had 64 usable bits. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-25perf_counter: Implement more accurate per task statisticsPeter Zijlstra
With the introduction of PERF_EVENT_READ we have the possibility to provide accurate counter values for individual tasks in a task hierarchy. However, due to the lazy context switching used for similar counter contexts our current per task counts are way off. In order to maintain some of the lazy switch benefits we don't disable it out-right, but simply iterate the active counters and flip the values between the contexts. This only reads the counters but does not need to reprogram the full PMU. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-25perf_counter: Add PERF_EVENT_READPeter Zijlstra
Provide a read() like event which can be used to log the counter value at specific sites such as child->parent folding on exit. In order to be useful, we log the counter parent ID, not the actual counter ID, since userspace can only relate parent IDs to perf_counter_attr constructs. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-25perf_counter, x86: Add mmap counter read supportPeter Zijlstra
Update the mmap control page with the needed information to use the userspace RDPMC instruction for self monitoring. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-25perf_counter: Add scale information to the mmap control pagePeter Zijlstra
Add the needed time scale to the self-profile mmap information. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-23perf_counter: Optimize perf_counter_alloc()'s inherit casePeter Zijlstra
We don't need to add usage counts for swcounter and attr usage models for inherited counters since the parent counter will always have one, which suffices to generate the needed output. This avoids up to 3 global atomic increments per inherited counter. LKML-Reference: <new-submission> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-23perf_counter: Push inherit into perf_counter_alloc()Peter Zijlstra
Teach perf_counter_alloc() about inheritance so that we can optimize the inherit path in the next patch. Remove the child_counter->atrr.inherit = 1 line because the only way to get there is if parent_counter->attr.inherit == 1 and we copy the attrs. 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> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-23perf_counter: Optimize perf_swcounter_event()Peter Zijlstra
Similar to tracepoints, use an enable variable to reduce overhead when unused. Only look for a counter of a particular event type when we know there is at least one in the system. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-20perf_counter: Push perf_sample_data through the swcounter codePeter Zijlstra
Push the perf_sample_data further outwards to the swcounter interface, to abstract it away some more. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-19perf_counter: Close race in perf_lock_task_context()Peter Zijlstra
perf_lock_task_context() is buggy because it can return a dead context. the RCU read lock in perf_lock_task_context() only guarantees the memory won't get freed, it doesn't guarantee the object is valid (in our case refcount > 0). Therefore we can return a locked object that can get freed the moment we release the rcu read lock. perf_pin_task_context() then increases the refcount and does an unlock on freed memory. That increased refcount will cause a double free, in case it started out with 0. Ammend this by including the get_ctx() functionality in perf_lock_task_context() (all users already did this later anyway), and return a NULL context when the found one is already dead. 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> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-19perf_counter: Simplify and fix task migration countingPeter Zijlstra
The task migrations counter was causing rare and hard to decypher memory corruptions under load. After a day of debugging and bisection we found that the problem was introduced with: 3f731ca: perf_counter: Fix cpu migration counter Turning them off fixes the crashes. Incidentally, the whole perf_counter_task_migration() logic can be done simpler as well, by injecting a proper sw-counter event. This cleanup also fixed the crashes. The precise failure mode is not completely clear yet, but we are clearly not unhappy about having a fix ;-) Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-18perf_counter: Add event overlow handlingPeter Zijlstra
Alternative method of mmap() data output handling that provides better overflow management and a more reliable data stream. Unlike the previous method, that didn't have any user->kernel feedback and relied on userspace keeping up, this method relies on userspace writing its last read position into the control page. It will ensure new output doesn't overwrite not-yet read events, new events for which there is no space left are lost and the overflow counter is incremented, providing exact event loss numbers. 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> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-15perf_counter: Fix ctx->mutex vs counter->mutex inversionPeter Zijlstra
Simon triggered a lockdep inversion report about us taking ctx->mutex vs counter->mutex in inverse orders. Fix that up. Reported-by: Simon Holm Thøgersen <odie@cs.aau.dk> Tested-by: Simon Holm Thøgersen <odie@cs.aau.dk> 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> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-13perf_counter: Fix stack corruption in perf_read_hwMarti Raudsepp
With PERF_FORMAT_ID, perf_read_hw now needs space for up to 4 values. 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> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-13perf_counter: Fix atomic_set vs. atomic64_t type mismatchPaul Mackerras
Using atomic_set on an atomic64_t variable gives a compiler warning on powerpc, and won't give the desired result at runtime. This fixes an instance of this error in the perf_counter code. Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <18995.20490.979429.244883@cargo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-12perf_counter: Add forward/backward attribute ABI compatibilityPeter Zijlstra
Provide for means of extending the perf_counter_attr in a 'natural' way. We allow growing the structure by appending fields at the end by specifying the full structure size inside it. When a new kernel sees a smaller (old) structure, it will 0 pad the tail. When an old kernel sees a larger (new) structure, it will verify the tail consists of 0s, otherwise fail. If we fail due to a size-mismatch, we return -E2BIG and write the kernel's native attribe size back into the provided structure. Furthermore, add some attribute verification, so that we'll fail counter creation when unknown bits are present (PERF_SAMPLE, PERF_FORMAT, or in the __reserved fields). (This ABI detail is introduced while keeping the existing syscall ABI.) 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> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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