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[PATCH 4/5] perf_events: add cgroup support (v7)

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From: Stephane Eranian
Subject: [PATCH 4/5] perf_events: add cgroup support (v7)
Date: Monday, January 3, 2011 - 9:20 am

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 in the flags argument
to the syscall.

For instance to measure in cgroup foo on CPU1 assuming
cgroupfs is mounted under /cgroup:

struct perf_event_attr attr;
int cgroup_fd, fd;

cgroup_fd = open("/cgroup/foo", O_RDONLY);
fd = perf_event_open(&attr, cgroup_fd, 1, -1, PERF_FLAG_PID_CGROUP);
close(cgroup_fd);

Signed-off-by: Stephane Eranian <eranian@google.com>
---

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index ed4ba11..5449b61 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -626,6 +626,7 @@ bool css_is_ancestor(struct cgroup_subsys_state *cg,
 /* Get id and depth of css */
 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 */
 
diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index ccefff0..cdbfcb8 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_CGROUP_PERF
+SUBSYS(perf)
+#endif
+
 /* */
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index dda5b0a..8843da4 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -464,6 +464,7 @@ 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, ...
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Previous thread: [GIT PULL] perf callchain fixlet by Frederic Weisbecker on Monday, January 3, 2011 - 10:45 am. (1 message)

Next thread: [PATCH] x86, UV: BAU extend for more than 16 cpus per socket by Cliff Wickman on Monday, January 3, 2011 - 11:03 am. (2 messages)