Messages in this thread Patch in this message | | | From | Namhyung Kim <> | Subject | [PATCH 02/10] perf/core: Add PERF_SAMPLE_CGROUP feature | Date | Mon, 24 Feb 2020 13:37:41 +0900 |
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The PERF_SAMPLE_CGROUP bit is to save (perf_event) cgroup information in the sample. It will add a 64-bit id to identify current cgroup and it's the file handle in the cgroup file system. Userspace should use this information with PERF_RECORD_CGROUP event to match which cgroup it belongs.
I put it before PERF_SAMPLE_AUX for simplicity since it just needs a 64-bit word. But if we want bigger samples, I can work on that direction too.
Cc: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- include/linux/perf_event.h | 1 + include/uapi/linux/perf_event.h | 3 ++- init/Kconfig | 3 ++- kernel/events/core.c | 22 ++++++++++++++++++++++ 4 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 6d4c22aee384..17b5bff045a6 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1001,6 +1001,7 @@ struct perf_sample_data { u64 stack_user_size; u64 phys_addr; + u64 cgroup; } ____cacheline_aligned; /* default value for data source */ diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index de2ab87ca92c..3a81e9806cb1 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -142,8 +142,9 @@ enum perf_event_sample_format { PERF_SAMPLE_REGS_INTR = 1U << 18, PERF_SAMPLE_PHYS_ADDR = 1U << 19, PERF_SAMPLE_AUX = 1U << 20, + PERF_SAMPLE_CGROUP = 1U << 21, - PERF_SAMPLE_MAX = 1U << 21, /* non-ABI */ + PERF_SAMPLE_MAX = 1U << 22, /* non-ABI */ __PERF_SAMPLE_CALLCHAIN_EARLY = 1ULL << 63, /* non-ABI; internal use */ }; diff --git a/init/Kconfig b/init/Kconfig index a34064a031a5..403ed2448b22 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1026,7 +1026,8 @@ config CGROUP_PERF help This option extends the perf per-cpu mode to restrict monitoring to threads which belong to the cgroup specified and run on the - designated cpu. + designated cpu. Or this can be used to have cgroup ID in samples + so that it can monitor performance events among cgroups. Say N if unsure. diff --git a/kernel/events/core.c b/kernel/events/core.c index b4ddfb26b5e9..68c5177e4492 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -1754,6 +1754,9 @@ static void __perf_event_header_size(struct perf_event *event, u64 sample_type) if (sample_type & PERF_SAMPLE_PHYS_ADDR) size += sizeof(data->phys_addr); + if (sample_type & PERF_SAMPLE_CGROUP) + size += sizeof(data->cgroup); + event->header_size = size; } @@ -6699,6 +6702,9 @@ void perf_output_sample(struct perf_output_handle *handle, if (sample_type & PERF_SAMPLE_PHYS_ADDR) perf_output_put(handle, data->phys_addr); + if (sample_type & PERF_SAMPLE_CGROUP) + perf_output_put(handle, data->cgroup); + if (sample_type & PERF_SAMPLE_AUX) { perf_output_put(handle, data->aux_size); @@ -6895,6 +6901,16 @@ void perf_prepare_sample(struct perf_event_header *header, if (sample_type & PERF_SAMPLE_PHYS_ADDR) data->phys_addr = perf_virt_to_phys(data->addr); +#ifdef CONFIG_CGROUP_PERF + if (sample_type & PERF_SAMPLE_CGROUP) { + struct cgroup *cgrp; + + /* protected by RCU */ + cgrp = task_css_check(current, perf_event_cgrp_id, 1)->cgroup; + data->cgroup = cgroup_id(cgrp); + } +#endif + if (sample_type & PERF_SAMPLE_AUX) { u64 size; @@ -11090,6 +11106,12 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr, if (attr->sample_type & PERF_SAMPLE_REGS_INTR) ret = perf_reg_validate(attr->sample_regs_intr); + +#ifndef CONFIG_CGROUP_PERF + if (attr->sample_type & PERF_SAMPLE_CGROUP) + return -EINVAL; +#endif + out: return ret; -- 2.25.0.265.gbab2e86ba0-goog
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