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author | Oleg Nesterov <oleg@redhat.com> | 2013-02-02 16:27:52 +0100 |
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committer | Oleg Nesterov <oleg@redhat.com> | 2013-02-08 18:28:02 +0100 |
commit | f22c1bb6b4706be3502b378cb14564449b15f983 (patch) | |
tree | ac7d09e3d42f4ab77cac56b9cb7fba2d4bcabf06 /include | |
parent | 1b47aefd9b6bd439a4be43c47acd22987ac22db8 (diff) | |
download | linux-stable-f22c1bb6b4706be3502b378cb14564449b15f983.tar.gz linux-stable-f22c1bb6b4706be3502b378cb14564449b15f983.tar.bz2 linux-stable-f22c1bb6b4706be3502b378cb14564449b15f983.zip |
perf: Introduce hw_perf_event->tp_target and ->tp_list
sys_perf_event_open()->perf_init_event(event) is called before
find_get_context(event), this means that event->ctx == NULL when
class->reg(TRACE_REG_PERF_REGISTER/OPEN) is called and thus it
can't know if this event is per-task or system-wide.
This patch adds hw_perf_event->tp_target for PERF_TYPE_TRACEPOINT,
this is analogous to PERF_TYPE_BREAKPOINT/bp_target we already have.
The patch also moves ->bp_target up so that it can overlap with the
new member, this can help the compiler to generate the better code.
trace_uprobe_register() will use it for prefiltering to avoid the
unnecessary breakpoints in mm's we do not want to trace.
->tp_target doesn't have its own reference, but we can rely on the
fact that either sys_perf_event_open() holds a reference, or it is
equal to event->ctx->task. So this pointer is always valid until
free_event().
Also add the "struct list_head tp_list" into this union. It is not
strictly necessary, but it can simplify the next changes and we can
add it for free.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/perf_event.h | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 42adf012145d..e47ee462c2f2 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -135,16 +135,21 @@ struct hw_perf_event { struct { /* software */ struct hrtimer hrtimer; }; + struct { /* tracepoint */ + struct task_struct *tp_target; + /* for tp_event->class */ + struct list_head tp_list; + }; #ifdef CONFIG_HAVE_HW_BREAKPOINT struct { /* breakpoint */ - struct arch_hw_breakpoint info; - struct list_head bp_list; /* * Crufty hack to avoid the chicken and egg * problem hw_breakpoint has with context * creation and event initalization. */ struct task_struct *bp_target; + struct arch_hw_breakpoint info; + struct list_head bp_list; }; #endif }; |