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2009-12-11Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (57 commits) x86, perf events: Check if we have APIC enabled perf_event: Fix variable initialization in other codepaths perf kmem: Fix unused argument build warning perf symbols: perf_header__read_build_ids() offset'n'size should be u64 perf symbols: dsos__read_build_ids() should read both user and kernel buildids perf tools: Align long options which have no short forms perf kmem: Show usage if no option is specified sched: Mark sched_clock() as notrace perf sched: Add max delay time snapshot perf tools: Correct size given to memset perf_event: Fix perf_swevent_hrtimer() variable initialization perf sched: Fix for getting task's execution time tracing/kprobes: Fix field creation's bad error handling perf_event: Cleanup for cpu_clock_perf_event_update() perf_event: Allocate children's perf_event_ctxp at the right time perf_event: Clean up __perf_event_init_context() hw-breakpoints: Modify breakpoints without unregistering them perf probe: Update perf-probe document perf probe: Support --del option trace-kprobe: Support delete probe syntax ...
2009-12-10perf_event: Fix variable initialization in other codepathsXiao Guangrong
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <4B20BAA6.7010609@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-10perf_event: Fix perf_swevent_hrtimer() variable initializationXiao Guangrong
fix: [<c0477471>] ? printk+0x1d/0x24 [<c01c98f9>] ? perf_prepare_sample+0x269/0x280 [<c0149231>] warn_slowpath_common+0x71/0xd0 [<c01c98f9>] ? perf_prepare_sample+0x269/0x280 [<c01492aa>] warn_slowpath_null+0x1a/0x20 [<c01c98f9>] perf_prepare_sample+0x269/0x280 [<c016e9f3>] ? cpu_clock+0x53/0x90 [<c01cc368>] __perf_event_overflow+0x2a8/0x300 [<c01ccc3b>] perf_event_overflow+0x1b/0x30 [<c01ccccf>] perf_swevent_hrtimer+0x7f/0x120 This is because 'data.raw' variable not initialize. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <4B208E93.1010801@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09perf_event: Cleanup for cpu_clock_perf_event_update()Xiao Guangrong
Using atomic64_xchg() instead of atomic64_read() and atomic64_set(). Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <4B1F19DC.90204@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09perf_event: Allocate children's perf_event_ctxp at the right timeXiao Guangrong
In current code, children task will allocate memory for 'child->perf_event_ctxp' if the parent is counted, we can do it only if the parent allowed children inherit it. It can save memory and reduce overhead. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <4B1F19A8.5040805@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09perf_event: Clean up __perf_event_init_context()Xiao Guangrong
Clean up the code a bit: - define 'perf_cpu_context' variable with 'static' - use kzalloc() instead of kmalloc() and memset() Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <4B1F194D.7080306@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09hw-breakpoints: Modify breakpoints without unregistering themFrederic Weisbecker
Currently, when ptrace needs to modify a breakpoint, like disabling it, changing its address, type or len, it calls modify_user_hw_breakpoint(). This latter will perform the heavy and racy task of unregistering the old breakpoint and registering a new one. This is racy as someone else might steal the reserved breakpoint slot under us, which is undesired as the breakpoint is only supposed to be modified, sometimes in the middle of a debugging workflow. We don't want our slot to be stolen in the middle. So instead of unregistering/registering the breakpoint, just disable it while we modify its breakpoint fields and re-enable it after if necessary. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prasad <prasad@linux.vnet.ibm.com> LKML-Reference: <1260347148-5519-1-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-07Merge branch 'for-next' into for-linusJiri Kosina
Conflicts: kernel/irq/chip.c
2009-12-06hw-breakpoints: Use overflow handler instead of the event callbackFrederic Weisbecker
struct perf_event::event callback was called when a breakpoint triggers. But this is a rather opaque callback, pretty tied-only to the breakpoint API and not really integrated into perf as it triggers even when we don't overflow. We prefer to use overflow_handler() as it fits into the perf events rules, being called only when we overflow. Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
2009-12-04tree-wide: fix assorted typos all over the placeAndré Goddard Rosa
That is "success", "unknown", "through", "performance", "[re|un]mapping" , "access", "default", "reasonable", "[con]currently", "temperature" , "channel", "[un]used", "application", "example","hierarchy", "therefore" , "[over|under]flow", "contiguous", "threshold", "enough" and others. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-12-02perf: Don't free perf_mmap_data until work has been doneKristian Høgsberg
In the CONFIG_PERF_USE_VMALLOC case, perf_mmap_data_free() only schedules the cleanup of the perf_mmap_data struct. In that case we have to wait until the work has been done before we free data. Signed-off-by: Kristian Høgsberg <krh@bitplanet.net> Cc: David S. Miller <davem@davemloft.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: <stable@kernel.org> LKML-Reference: <1259697901-1747-1-git-send-email-krh@bitplanet.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-01perf_event: Initialize data.period in perf_swevent_hrtimer()Xiao Guangrong
In current code in perf_swevent_hrtimer(), data.period is not initialized, The result is obvious wrong: # ./perf record -f -e cpu-clock make # ./perf report # Samples: 1740 # # Overhead Command ...... # ........ ........ .......................................... # 1025422183050275328.00% sh libc-2.9.90.so ... 1025422183050275328.00% perl libperl.so ... 1025422168240043264.00% perl [kernel] ... 1025422030011210752.00% perl [kernel] ... Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: <stable@kernel.org> LKML-Reference: <4B14E220.2050107@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-26perf_events: Fix read() bogus counts when in error stateStephane Eranian
When a pinned group cannot be scheduled it goes into error state. Normally a group cannot go out of error state without being explicitly re-enabled or disabled. There was a bug in per-thread mode, whereby upon termination of the thread, the group would transition from error to off leading to bogus counts and timing information returned by read(). Fix it by clearing the error state. Signed-off-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: perfmon2-devel@lists.sourceforge.net LKML-Reference: <4b0eb9ce.0508d00a.573b.ffffeab6@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-26hw-breakpoints: Fix unused function in off-caseFrederic Weisbecker
bp_perf_event_destroy() is unused in its off-case version, let's remove it to fix the following warning reported by Stephen Rothwell in linux-next: kernel/perf_event.c:4306: warning: 'bp_perf_event_destroy' defined but not used Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <1259180453-5813-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-26hw-breakpoints: Improve in-kernel event creation error granularityFrederic Weisbecker
In fail case, perf_event_create_kernel_counter() returns NULL instead of an error, which doesn't help us to inform the user about the origin of the problem from the outer most callers. Often we can just return -EINVAL, which doesn't help anyone when it's eventually about a memory allocation failure. Then, this patch makes perf_event_create_kernel_counter() always return a detailed error code. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Prasad <prasad@linux.vnet.ibm.com> LKML-Reference: <1259210142-5714-2-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-24perf_events: Fix bad software/trace event recursion countingFrederic Weisbecker
Commit 4ed7c92d68a5387ba5f7030dc76eab03558e27f5 (perf_events: Undo some recursion damage) has introduced a bad reference counting of the recursion context. putting the context behaves like getting it, dropping every software/trace events after the first one in a context. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1259091502-5171-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-24perf_events: Fix bogus copy_to_user() in perf_event_read_group()Stephane Eranian
When using an event group, the value and id for non leaders events were wrong due to invalid offset into the outgoing buffer. Signed-off-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: paulus@samba.org Cc: perfmon2-devel@lists.sourceforge.net LKML-Reference: <4b0b71e1.0508d00a.075e.ffff84a3@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-23perf: Add kernel side syscall events support for breakpointsFrederic Weisbecker
Add the remaining necessary bits to support breakpoints created through perf syscall. We don't use the software counter interface as: - We don't need to check against recursion, this is already done in hardware breakpoints arch level. - We already know the perf event we are dealing with when the event is to be committed. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Prasad <prasad@linux.vnet.ibm.com> LKML-Reference: <1258987355-8751-3-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-23perf_events: Restore sanity to scaling landPeter Zijlstra
It is quite possible to call update_event_times() on a context that isn't actually running and thereby confuse the thing. perf stat was reporting !100% scale values for software counters (2e2af50b perf_events: Disable events when we detach them, solved the worst of that, but there was still some left). The thing that happens is that because we are not self-reaping (we have a caring parent) there is a time between the last schedule (out) and having do_exit() called which will detach the events. This period would be accounted as enabled,!running because the event->state==INACTIVE, even though !event->ctx->is_active. Similar issues could have been observed by calling read() on a event while the attached task was not scheduled in. Solve this by teaching update_event_times() about ctx->is_active. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1258984836.4531.480.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-23perf_events: Undo some recursion damagePeter Zijlstra
Make perf_swevent_get_recursion_context return a context number and disable preemption. This could be used to remove the IRQ disable from the trace bit and index the per-cpu buffer with. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091123103819.993226816@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-23perf_events: Fix __perf_event_exit_task() vs. update_event_times() lockingPeter Zijlstra
Move the update_event_times() call in __perf_event_exit_task() into list_del_event() because that holds the proper lock (ctx->lock) and seems a more natural place to do the last time update. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091123103819.842455480@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-23perf_events: Update the context time on exitPeter Zijlstra
It appeared we did call update_event_times() on exit, but we failed to update the context time, which renders the former moot. Locking is a bit iffy, we call update_event_times under ctx->mutex instead of ctx->lock - the next patch fixes this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091123103819.764207355@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-23perf_events: Disable events when we detach themPeter Zijlstra
If we leave the event in STATE_INACTIVE, any read of the event after the detach will increase the running count but not the enabled count and cause funny scaling artefacts. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091123103819.689055515@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-23perf_events: Fix style nitsPeter Zijlstra
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091123103819.613427378@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-23perf_events: Undo copy/paste damagePeter Zijlstra
We had two almost identical functions, avoid the duplication. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <20091123103819.537537928@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-23perf_events: Optimize the swcounter hotpathIngo Molnar
The structure init creates a bit memcpy, which shows up big time in perf annotate output: : ffffffff810a859d <__perf_sw_event>: 1.68 : ffffffff810a859d: 55 push %rbp 1.69 : ffffffff810a859e: 41 89 fa mov %edi,%r10d 0.01 : ffffffff810a85a1: 49 89 c9 mov %rcx,%r9 0.00 : ffffffff810a85a4: 31 c0 xor %eax,%eax 1.71 : ffffffff810a85a6: b9 16 00 00 00 mov $0x16,%ecx 0.00 : ffffffff810a85ab: 48 89 e5 mov %rsp,%rbp 0.00 : ffffffff810a85ae: 48 83 ec 60 sub $0x60,%rsp 1.52 : ffffffff810a85b2: 48 8d 7d a0 lea -0x60(%rbp),%rdi 85.20 : ffffffff810a85b6: f3 ab rep stos %eax,%es:(%rdi) None of the callees depends on the structure being pre-initialized, so only initialize ->addr. This gets rid of the memcpy overhead. 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>
2009-11-22perf_events: Fix modular buildIngo Molnar
Fix: ERROR: "perf_swevent_put_recursion_context" [fs/ext4/ext4.ko] undefined! ERROR: "perf_swevent_get_recursion_context" [fs/ext4/ext4.ko] undefined! Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jason Baron <jbaron@redhat.com> LKML-Reference: <1258864015-10579-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-22perf_event: Remove redundant zero fillMárton Németh
The buffer is first zeroed out by memset(). Then strncpy() is used to fill the content. The strncpy() function also pads the string till the end of the specified length, which is redundant. The strncpy() does not ensures that the string will be properly closed with 0. Use strlcpy() instead. The semantic match that finds this kind of pattern is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression buffer; expression size; expression str; @@ memset(buffer, 0, size); ... - strncpy( + strlcpy( buffer, str, sizeof(buffer) ); @@ expression buffer; expression size; expression str; @@ memset(&buffer, 0, size); ... - strncpy( + strlcpy( &buffer, str, sizeof(buffer)); @@ expression buffer; identifier field; expression size; expression str; @@ memset(buffer, 0, size); ... - strncpy( + strlcpy( buffer->field, str, sizeof(buffer->field) ); @@ expression buffer; identifier field; expression size; expression str; @@ memset(&buffer, 0, size); ... - strncpy( + strlcpy( buffer.field, str, sizeof(buffer.field)); // </smpl> On strncpy() vs strlcpy() see http://www.gratisoft.us/todd/papers/strlcpy.html . Signed-off-by: Márton Németh <nm127@freemail.hu> Cc: Julia Lawall <julia@diku.dk> Cc: cocci@diku.dk Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <4B086547.5040100@freemail.hu> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-22tracing: Use the perf recursion protection from trace eventFrederic Weisbecker
When we commit a trace to perf, we first check if we are recursing in the same buffer so that we don't mess-up the buffer with a recursing trace. But later on, we do the same check from perf to avoid commit recursion. The recursion check is desired early before we touch the buffer but we want to do this check only once. Then export the recursion protection from perf and use it from the trace events before submitting a trace. v2: Put appropriate Reported-by tag Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jason Baron <jbaron@redhat.com> LKML-Reference: <1258864015-10579-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf_events: Fix default watermark calculationStephane Eranian
This patch fixes the default watermark value for the sampling buffer. With the existing calculation (watermark = max(PAGE_SIZE, max_size / 2)), no notification was ever received when the buffer was exactly 1 page. This was because you would never cross the threshold (there is no partial samples). In certain configuration, there was no possibilty detecting the problem because there was not enough space left to store the LOST record.In fact, there may be a more generic problem here. The kernel should ensure that there is alaways enough space to store one LOST record. This patch sets the default watermark to half the buffer size. With such limit, we are guaranteed to get a notification even with a single page buffer assuming no sample is bigger than a page. Signed-off-by: Stephane Eranian <eranian@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212509.344964101@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1256302576-6169-1-git-send-email-eranian@gmail.com>
2009-11-21perf: Fix locking for PERF_FORMAT_GROUPPeter Zijlstra
We should hold event->child_mutex when iterating the inherited counters, we should hold ctx->mutex when iterating siblings. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212509.251030114@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf: Fix event scaling for inherited countersPeter Zijlstra
Properly account the full hierarchy of counters for both the count (we already did so) and the scale times (new). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212509.153379276@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf: Fix time lockingPeter Zijlstra
Most sites updating ctx->time and event times do so under ctx->lock, make sure they all do. This was made possible by removing the __perf_event_read() call from __perf_event_sync_stat(), which already had this lock taken. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212509.102316434@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf: Simplify __perf_event_readPeter Zijlstra
cpuctx is always active, task context is always active for current the previous condition verifies that if its a task context its for current, hence we can assume ctx->is_active. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212509.000272254@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf: Simplify __perf_event_sync_statPeter Zijlstra
Removes constraints from __perf_event_read() by leaving it with a single callsite; this callsite had ctx->lock held, the other one does not. Removes some superfluous code from __perf_event_sync_stat(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212508.918544317@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf: Optimize __perf_event_read()Peter Zijlstra
Both callers actually have IRQs disabled, no need doing so again. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212508.863685796@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf: Optimize perf_event_task_sched_outPeter Zijlstra
Remove an update_context_time() call from the perf_event_task_sched_out() path and into the branch its needed. The call was both superfluous, because __perf_event_sched_out() already does it, and wrong, because it was done without holding ctx->lock. Place it in perf_event_sync_stat(), which is the only place it is needed and which does already hold ctx->lock. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212508.779516394@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf: Fix PERF_FORMAT_GROUP scale infoPeter Zijlstra
As Corey reported, the total_enabled and total_running times could occasionally be 0, even though there were events counted. It turns out this is because we record the times before reading the counter while the latter updates the times. This patch corrects that. While looking at this code I found that there is a lot of locking iffyness around, the following patches correct most of that. Reported-by: Corey Ashford <cjashfor@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212508.685559857@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf: Optimize perf_event_mmap_ctx()Peter Zijlstra
Remove a rcu_read_{,un}lock() pair and a few conditionals. We can remove the rcu_read_lock() by increasing the scope of one in the calling function. We can do away with the system_state check if the machine still boots after this patch (seems to be the case). We can do away with the list_empty() check because the bare list_for_each_entry_rcu() reduces to that now that we've removed everything else. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212508.606459548@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf: Optimize perf_event_comm_ctx()Peter Zijlstra
Remove a rcu_read_{,un}lock() pair and a few conditionals. We can remove the rcu_read_lock() by increasing the scope of one in the calling function. We can do away with the system_state check if the machine still boots after this patch (seems to be the case). We can do away with the list_empty() check because the bare list_for_each_entry_rcu() reduces to that now that we've removed everything else. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212508.527608793@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf: Optimize perf_event_task_ctx()Peter Zijlstra
Remove a rcu_read_{,un}lock() pair and a few conditionals. We can remove the rcu_read_lock() by increasing the scope of one in the calling function. We can do away with the system_state check if the machine still boots after this patch (seems to be the case). We can do away with the list_empty() check because the bare list_for_each_entry_rcu() reduces to that now that we've removed everything else. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212508.452227115@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf: Optimize perf_swevent_ctx_event()Peter Zijlstra
Remove a rcu_read_{,un}lock() pair and a few conditionals. We can remove the rcu_read_lock() by increasing the scope of one in the calling function. We can do away with the system_state check if the machine still boots after this patch (seems to be the case). We can do away with the list_empty() check because the bare list_for_each_entry_rcu() reduces to that now that we've removed everything else. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212508.378188589@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf: Optimize some swcounter attr.sample_period==1 pathsPeter Zijlstra
Avoid the rather expensive perf_swevent_set_period() if we know we have to sample every single event anyway. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212508.299508332@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21perf: Allow for custom overflow handlersPeter Zijlstra
in-kernel perf users might wish to have custom actions on the sample interrupt. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <20091120212508.222339539@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-21Merge branch 'tracing/hw-breakpoints' into perf/coreIngo Molnar
Conflicts: arch/x86/kernel/kprobes.c kernel/trace/Makefile Merge reason: hw-breakpoints perf integration is looking good in testing and in reviews, plus conflicts are mounting up - so merge & resolve. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-16perf_event: Optimize perf_output_lock()Peter Zijlstra
The purpose of perf_output_{un,}lock() is to: 1) avoid publishing incomplete data [ possible when publishing a head that is ahead of an entry that is still being written ] 2) guarantee fwd progress [ a simple refcount on pending writers doesn't need to drop to 0, making it so would end up implementing something like forced quiecent states of RCU ] To satisfy the above without undue complexity it serializes between CPUs, this means that a pending writer can only be the same cpu in a nested context, and since (under normal operation) a cpu always makes progress we're good -- if the head is only published when the bottom most writer completes. Now we don't need to disable IRQs in order to serialize between CPUs, disabling preemption ought to be sufficient, esp since we already deal with nesting due to NMIs. This avoids potentially expensive (and needless) local IRQ disable/enable ops. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1258373161.26714.254.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-15Merge branches 'perf/powerpc' and 'perf/bench' into perf/coreIngo Molnar
Merge reason: Both 'perf bench' and the pending PowerPC changes are now ready for the next merge window. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-08hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf eventsFrederic Weisbecker
This patch rebase the implementation of the breakpoints API on top of perf events instances. Each breakpoints are now perf events that handle the register scheduling, thread/cpu attachment, etc.. The new layering is now made as follows: ptrace kgdb ftrace perf syscall \ | / / \ | / / / Core breakpoint API / / | / | / Breakpoints perf events | | Breakpoints PMU ---- Debug Register constraints handling (Part of core breakpoint API) | | Hardware debug registers Reasons of this rewrite: - Use the centralized/optimized pmu registers scheduling, implying an easier arch integration - More powerful register handling: perf attributes (pinned/flexible events, exclusive/non-exclusive, tunable period, etc...) Impact: - New perf ABI: the hardware breakpoints counters - Ptrace breakpoints setting remains tricky and still needs some per thread breakpoints references. Todo (in the order): - Support breakpoints perf counter events for perf tools (ie: implement perf_bpcounter_event()) - Support from perf tools Changes in v2: - Follow the perf "event " rename - The ptrace regression have been fixed (ptrace breakpoint perf events weren't released when a task ended) - Drop the struct hw_breakpoint and store generic fields in perf_event_attr. - Separate core and arch specific headers, drop asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h - Use new generic len/type for breakpoint - Handle off case: when breakpoints api is not supported by an arch Changes in v3: - Fix broken CONFIG_KVM, we need to propagate the breakpoint api changes to kvm when we exit the guest and restore the bp registers to the host. Changes in v4: - Drop the hw_breakpoint_restore() stub as it is only used by KVM - EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a module - Restore the breakpoints unconditionally on kvm guest exit: TIF_DEBUG_THREAD doesn't anymore cover every cases of running breakpoints and vcpu->arch.switch_db_regs might not always be set when the guest used debug registers. (Waiting for a reliable optimization) Changes in v5: - Split-up the asm-generic/hw-breakpoint.h moving to linux/hw_breakpoint.h into a separate patch - Optimize the breakpoints restoring while switching from kvm guest to host. We only want to restore the state if we have active breakpoints to the host, otherwise we don't care about messed-up address registers. - Add asm/hw_breakpoint.h to Kbuild - Fix bad breakpoint type in trace_selftest.c Changes in v6: - Fix wrong header inclusion in trace.h (triggered a build error with CONFIG_FTRACE_SELFTEST Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jan Kiszka <jan.kiszka@web.de> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Avi Kivity <avi@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org>
2009-11-04Merge commit 'v2.6.32-rc6' into perf/coreIngo Molnar
Conflicts: tools/perf/Makefile Merge reason: Resolve the conflict, merge to upstream and merge in perf fixes so we can add a dependent patch. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03perf/core: Add a callback to perf eventsFrederic Weisbecker
A simple callback in a perf event can be used for multiple purposes. For example it is useful for triggered based events like hardware breakpoints that need a callback to dispatch a triggered breakpoint event. v2: Simplify a bit the callback attribution as suggested by Paul Mackerras Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "K.Prasad" <prasad@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mundt <lethal@linux-sh.org>
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