Messages in this thread | | | Date | Thu, 7 Oct 2010 15:45:20 +0200 | Subject | Re: [RFC PATCH 1/2] perf_events: add support for per-cpu per-cgroup monitoring (v4) | From | stephane eranian <> |
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On Thu, Oct 7, 2010 at 3:20 AM, Li Zefan <lizf@cn.fujitsu.com> wrote: > Stephane Eranian wrote: >> This kernel patch adds the ability to filter monitoring based on >> container groups (cgroups). This is for use in per-cpu mode only. >> >> The cgroup to monitor is passed as a file descriptor in the pid >> argument to the syscall. The file descriptor must be opened to >> the cgroup name in the cgroup filesystem. For instance, if the >> cgroup name is foo and cgroupfs is mounted in /cgroup, then the >> file descriptor is opened to /cgroup/foo. Cgroup mode is >> activated by passing PERF_FLAG_PID_CGROUP into the flags argument >> to the syscall. >> >> Signed-off-by: Stephane Eranian <eranian@google.com> >> >> --- >> >> diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h >> index 709dfb9..67cf276 100644 >> --- a/include/linux/cgroup.h >> +++ b/include/linux/cgroup.h >> @@ -623,6 +623,8 @@ bool css_is_ancestor(struct cgroup_subsys_state *cg, >> unsigned short css_id(struct cgroup_subsys_state *css); >> unsigned short css_depth(struct cgroup_subsys_state *css); >> >> +struct cgroup_subsys_state *cgroup_css_from_dir(struct file *f, int id); >> + >> #else /* !CONFIG_CGROUPS */ >> >> static inline int cgroup_init_early(void) { return 0; } >> diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h >> index ccefff0..93f86b7 100644 >> --- a/include/linux/cgroup_subsys.h >> +++ b/include/linux/cgroup_subsys.h >> @@ -65,4 +65,8 @@ SUBSYS(net_cls) >> SUBSYS(blkio) >> #endif >> >> +#ifdef CONFIG_PERF_EVENTS >> +SUBSYS(perf) >> +#endif >> + >> /* */ >> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h >> index 61b1e2d..ad79f0a 100644 >> --- a/include/linux/perf_event.h >> +++ b/include/linux/perf_event.h >> @@ -454,6 +454,7 @@ enum perf_callchain_context { >> >> #define PERF_FLAG_FD_NO_GROUP (1U << 0) >> #define PERF_FLAG_FD_OUTPUT (1U << 1) >> +#define PERF_FLAG_PID_CGROUP (1U << 2) /* pid=cgroup id, per-cpu mode */ >> >> #ifdef __KERNEL__ >> /* >> @@ -461,6 +462,7 @@ enum perf_callchain_context { >> */ >> >> #ifdef CONFIG_PERF_EVENTS >> +# include <linux/cgroup.h> >> # include <asm/perf_event.h> >> # include <asm/local64.h> >> #endif >> @@ -698,6 +700,18 @@ struct swevent_hlist { >> #define PERF_ATTACH_CONTEXT 0x01 >> #define PERF_ATTACH_GROUP 0x02 >> >> +#ifdef CONFIG_CGROUPS >> +struct perf_cgroup_time { >> + u64 time; >> + u64 timestamp; >> +}; >> + >> +struct perf_cgroup { >> + struct cgroup_subsys_state css; >> + struct perf_cgroup_time *time; >> +}; > > Can we avoid adding this perf cgroup subsystem? It has 2 disavantages: > Well, I need to maintain some timing information for each cgroup. This has to be stored somewhere.
> - If one mounted cgroup fs without perf cgroup subsys, he can't monitor it.
That's unfortunately true ;-)
> - If there are several different cgroup mount points, only one can be > monitored. > > To choose which cgroup hierarchy to monitor, hierarchy id can be passed > from userspace, which is the 2nd column below: > Ok, I will investigate this. As long as the hierarchy id is unique AND it can be searched, then we can use it. Using /proc is fine with me.
> $ cat /proc/cgroups > #subsys_name hierarchy num_cgroups enabled > debug 0 1 1 > net_cls 0 1 1 > >> +#endif > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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