Messages in this thread Patch in this message | | | Date | Thu, 22 May 2014 09:52:46 +0300 | From | Adrian Hunter <> | Subject | Re: ye olde task_ctx_sched_out trace. |
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On 05/21/2014 06:32 PM, Peter Zijlstra wrote: > On Wed, May 21, 2014 at 05:30:13PM +0200, Peter Zijlstra wrote: >> A little something like so I suppose. >> >> --- > >> +void perf_event_exec(void) >> +{ >> + struct perf_event_context *ctx; >> + int ctxn; >> + >> + rcu_read_lock(); >> + for_each_task_context_nr(ctxn) { >> + ctx = task->perf_event_ctxp[ctxn]; > > s/task/current/ > >> + if (!ctx) >> + continue; >> + >> + perf_event_enable_on_exec(ctx); >> + } >> + rcu_read_unlock(); >> +} > > > It would help if I pasted the one that actually compiles I suppose.. > > --- > fs/exec.c | 1 + > include/linux/perf_event.h | 1 + > kernel/events/core.c | 28 ++++++++++++++++------------ > 3 files changed, 18 insertions(+), 12 deletions(-) > > diff --git a/fs/exec.c b/fs/exec.c > index 476f3ebf437e..8d51d7ce3dcf 100644 > --- a/fs/exec.c > +++ b/fs/exec.c > @@ -1111,6 +1111,7 @@ void setup_new_exec(struct linux_binprm * bprm) > set_dumpable(current->mm, suid_dumpable); > > set_task_comm(current, kbasename(bprm->filename)); > + perf_event_exec();
Shouldn't that be the other way around i.e.
+ perf_event_exec(); set_task_comm(current, kbasename(bprm->filename));
Also what about flagging the comm event that corresponds to an exec e.g.
diff --git a/fs/exec.c b/fs/exec.c index 476f3eb..28d69a1 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1046,13 +1046,13 @@ EXPORT_SYMBOL_GPL(get_task_comm); * so that a new one can be started */ -void set_task_comm(struct task_struct *tsk, const char *buf) +void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec) { task_lock(tsk); trace_task_rename(tsk, buf); strlcpy(tsk->comm, buf, sizeof(tsk->comm)); task_unlock(tsk); - perf_event_comm(tsk); + perf_event_comm(tsk, exec); } int flush_old_exec(struct linux_binprm * bprm) @@ -1110,7 +1110,7 @@ void setup_new_exec(struct linux_binprm * bprm) else set_dumpable(current->mm, suid_dumpable); - set_task_comm(current, kbasename(bprm->filename)); + __set_task_comm(current, kbasename(bprm->filename), true); /* Set the new mm task size. We have to do that late because it may * depend on TIF_32BIT which is only updated in flush_thread() on diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index af6dcf1..26614312 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -694,7 +694,7 @@ extern struct perf_guest_info_callbacks *perf_guest_cbs; extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks); extern int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks); -extern void perf_event_comm(struct task_struct *tsk); +extern void perf_event_comm(struct task_struct *tsk, bool exec); extern void perf_event_fork(struct task_struct *tsk); /* Callchains */ @@ -801,7 +801,7 @@ static inline int perf_unregister_guest_info_callbacks (struct perf_guest_info_callbacks *callbacks) { return 0; } static inline void perf_event_mmap(struct vm_area_struct *vma) { } -static inline void perf_event_comm(struct task_struct *tsk) { } +static inline void perf_event_comm(struct task_struct *tsk, bool exec) { } static inline void perf_event_fork(struct task_struct *tsk) { } static inline void perf_event_init(void) { } static inline int perf_swevent_get_recursion_context(void) { return -1; } diff --git a/include/linux/sched.h b/include/linux/sched.h index 25f54c7..cadcf38 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2376,7 +2376,11 @@ extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, i struct task_struct *fork_idle(int); extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); -extern void set_task_comm(struct task_struct *tsk, const char *from); +extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); +static inline void set_task_comm(struct task_struct *tsk, const char *from) +{ + __set_task_comm(tsk, from, false); +} extern char *get_task_comm(char *to, struct task_struct *tsk); #ifdef CONFIG_SMP diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index e3fc8f0..8ae875a 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -501,7 +501,12 @@ struct perf_event_mmap_page { #define PERF_RECORD_MISC_GUEST_KERNEL (4 << 0) #define PERF_RECORD_MISC_GUEST_USER (5 << 0) +/* + * PERF_RECORD_MISC_MMAP_DATA and PERF_RECORD_MISC_COMM_EXEC are used on + * different events so can reuse the same bit position. + */ #define PERF_RECORD_MISC_MMAP_DATA (1 << 13) +#define PERF_RECORD_MISC_COMM_EXEC (1 << 13) /* * Indicates that the content of PERF_SAMPLE_IP points to * the actual instruction that triggered the event. See also diff --git a/kernel/events/core.c b/kernel/events/core.c index ed50b09..760abd0 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5067,7 +5067,7 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event) NULL); } -void perf_event_comm(struct task_struct *task) +void perf_event_comm(struct task_struct *task, bool exec) { struct perf_comm_event comm_event; struct perf_event_context *ctx; @@ -5093,7 +5093,7 @@ void perf_event_comm(struct task_struct *task) .event_id = { .header = { .type = PERF_RECORD_COMM, - .misc = 0, + .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, /* .size */ }, /* .pid */
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