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authorNamhyung Kim <namhyung@kernel.org>2020-03-25 21:45:29 +0900
committerArnaldo Carvalho de Melo <acme@redhat.com>2020-03-27 10:41:44 -0300
commit6546b19f95acc986807de981402bbac6b3a94b0f (patch)
treed1d33094a9ed4d73d68f93fc92b954ca5d553caf /kernel/events
parent96aaab686505c449e24d76e76507290dcc30e008 (diff)
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 <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lore.kernel.org/lkml/20200325124536.2800725-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/core.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 994932d5e474..1569979c8912 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;