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path: root/kernel/trace/trace_event_profile.c
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2009-10-05tracing: Use free_percpu instead of kfreeFrederic Weisbecker
In the event->profile_enable() failure path, we release the per cpu buffers using kfree which is wrong because they are per cpu pointers. Although free_percpu only wraps kfree for now, that may change in the future so lets use the correct way. Reported-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Li Zefan <lizf@cn.fujitsu.com>
2009-10-05tracing: Check total refcount before releasing bufs in profile_enable failureFrederic Weisbecker
When we call the profile_enable() callback of an event, we release the shared perf event tracing buffers unconditionnaly in the failure path. This is wrong because there may be other users of these. Then check the total refcount before doing this. Reported-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Li Zefan <lizf@cn.fujitsu.com>
2009-09-20tracing: Export trace_profile_buf symbolsPeter Zijlstra
ERROR: "trace_profile_buf_nmi" [fs/jbd2/jbd2.ko] undefined! ERROR: "trace_profile_buf" [fs/jbd2/jbd2.ko] undefined! ERROR: "trace_profile_buf_nmi" [fs/ext4/ext4.ko] undefined! ERROR: "trace_profile_buf" [fs/ext4/ext4.ko] undefined! ERROR: "trace_profile_buf_nmi" [arch/x86/kvm/kvm.ko] undefined! ERROR: "trace_profile_buf" [arch/x86/kvm/kvm.ko] undefined! Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1253442878.7542.3.camel@laptop> [ fixed whitespace noise and checkpatch complaint ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-18tracing: Allocate the ftrace event profile buffer dynamicallyFrederic Weisbecker
Currently the trace event profile buffer is allocated in the stack. But this may be too much for the stack, as the events can have large statically defined field size and can also grow with dynamic arrays. Allocate two per cpu buffer for all profiled events. The first cpu buffer is used to host every non-nmi context traces. It is protected by disabling the interrupts while writing and committing the trace. The second buffer is reserved for nmi. So that there is no race between them and the first buffer. The whole write/commit section is rcu protected because we release these buffers while deactivating the last profiling trace event. v2: Move the buffers from trace_event to be global, as pointed by Steven Rostedt. v3: Fix the syscall events to handle the profiling buffer races by disabling interrupts, now that the buffers are globals. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ingo Molnar <mingo@elte.hu>
2009-09-18tracing: Factorize the events profile accountingFrederic Weisbecker
Factorize the events enabling accounting in a common tracing core helper. This reduces the size of the profile_enable() and profile_disable() callbacks for each trace events. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ingo Molnar <mingo@elte.hu>
2009-09-12tracing/profile: fix profile_disable vs module_unloadLi Zefan
If the correspoding module is unloaded before ftrace_profile_disable() is called, event->profile_disable() won't be called, which can cause oops: # insmod trace-events-sample.ko # perf record -f -a -e sample:foo_bar sleep 3 & # sleep 1 # rmmod trace_events_sample # insmod trace-events-sample.ko OOPS! Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4A9214E3.2070807@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-08-06ftrace: Fix perf-tracepoint OOPSPeter Zijlstra
Not all tracepoints are created equal, in specific the ftrace tracepoints are created with TRACE_EVENT_FORMAT() which does not generate the needed bits to tie them into perf counters. For those events, don't create the 'id' file and fail ->profile_enable when their ID is specified through other means. Reported-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1249497664.5890.4.camel@laptop> [ v2: fix build error in the !CONFIG_EVENT_PROFILE case ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-06tracing/events: fix concurrent access to ftrace_events listLi Zefan
A module will add/remove its trace events when it gets loaded/unloaded, so the ftrace_events list is not "const", and concurrent access needs to be protected. This patch thus fixes races between loading/unloding modules and read 'available_events' or read/write 'set_event', etc. Below shows how to reproduce the race: # for ((; ;)) { cat /mnt/tracing/available_events; } > /dev/null & # for ((; ;)) { insmod trace-events-sample.ko; rmmod sample; } & After a while: BUG: unable to handle kernel paging request at 0010011c IP: [<c1080f27>] t_next+0x1b/0x2d ... Call Trace: [<c10c90e6>] ? seq_read+0x217/0x30d [<c10c8ecf>] ? seq_read+0x0/0x30d [<c10b4c19>] ? vfs_read+0x8f/0x136 [<c10b4fc3>] ? sys_read+0x40/0x65 [<c1002a68>] ? sysenter_do_call+0x12/0x36 [ Impact: fix races when concurrent accessing ftrace_events list ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4A00F709.3080800@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14tracing/events: convert event call sites to use a link listSteven Rostedt
Impact: makes it possible to define events in modules The events are created by reading down the section that they are linked in by the macros. But this is not scalable to modules. This patch converts the manipulations to use a global link list, and on boot up it adds the items in the section to the list. This change will allow modules to add their tracing events to the list as well. Note, this change alone does not permit modules to use the TRACE_EVENT macros, but the change is needed for them to eventually do so. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-07tracing/ftrace: factorize the tracing files creationFrederic Weisbecker
Impact: cleanup Most of the tracing files creation follow the same pattern: ret = debugfs_create_file(...) if (!ret) pr_warning("Couldn't create ... entry\n") Unify it! Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1238109938-11840-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-03-20ftrace: event profile hooksPeter Zijlstra
Impact: new tracing infrastructure feature Provide infrastructure to generate software perf counter events from tracepoints. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20090319194233.557364871@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>