From: Namhyung Kim Date: Wed, 25 Mar 2020 12:45:29 +0000 (+0900) Subject: perf/core: Add PERF_SAMPLE_CGROUP feature X-Git-Tag: v5.10.7~2877^2^2~23 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6546b19f95acc986807de981402bbac6b3a94b0f;p=platform%2Fkernel%2Flinux-rpi.git perf/core: Add PERF_SAMPLE_CGROUP feature 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. Committer testing: $ pahole perf_sample_data | grep -w cgroup -B5 -A5 /* --- cacheline 4 boundary (256 bytes) was 56 bytes ago --- */ struct perf_regs regs_intr; /* 312 16 */ /* --- cacheline 5 boundary (320 bytes) was 8 bytes ago --- */ u64 stack_user_size; /* 328 8 */ u64 phys_addr; /* 336 8 */ u64 cgroup; /* 344 8 */ /* size: 384, cachelines: 6, members: 22 */ /* padding: 32 */ }; $ Signed-off-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Acked-by: Peter Zijlstra (Intel) Acked-by: Tejun Heo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Johannes Weiner Cc: Mark Rutland Cc: Zefan Li Link: http://lore.kernel.org/lkml/20200325124536.2800725-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 8768a39..9c3e7619 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1020,6 +1020,7 @@ 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 de95f6c..7b2d6fc 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 20a6ac3..7766b06 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1027,7 +1027,8 @@ 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 994932d..1569979 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -1862,6 +1862,9 @@ 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; } @@ -6867,6 +6870,9 @@ 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); @@ -7066,6 +7072,16 @@ 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; @@ -11264,6 +11280,12 @@ 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;