From: Stephane Eranian <eranian@google.com>
To: linux-kernel@vger.kernel.org
Cc: peterz@infradead.org, mingo@elte.hu, paulus@samba.org,
davem@davemloft.net, fweisbec@gmail.com,
perfmon2-devel@lists.sf.net, eranian@gmail.com,
eranian@google.com, robert.richter@amd.com
Subject: [PATCH] perf_events: fix broken event grouping
Date: Wed, 15 Sep 2010 17:44:01 +0200 [thread overview]
Message-ID: <4c90ea16.21edd80a.4b94.2495@mx.google.com> (raw)
Events were not grouped anymore. The reason was that in
perf_event_open(), the field event->group_leader was
initialized before the function looked up the group_fd
to find the event leader. This patch fixes this by
reordering the code correctly.
Signed-off-by: Stephane Eranian <eranian@google.com>
--
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 86f394e..ce95617 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -5550,17 +5550,11 @@ SYSCALL_DEFINE5(perf_event_open,
if (event_fd < 0)
return event_fd;
- event = perf_event_alloc(&attr, cpu, group_leader, NULL, NULL);
- if (IS_ERR(event)) {
- err = PTR_ERR(event);
- goto err_fd;
- }
-
if (group_fd != -1) {
group_leader = perf_fget_light(group_fd, &fput_needed);
if (IS_ERR(group_leader)) {
err = PTR_ERR(group_leader);
- goto err_alloc;
+ goto err_fd;
}
group_file = group_leader->filp;
if (flags & PERF_FLAG_FD_OUTPUT)
@@ -5569,6 +5563,12 @@ SYSCALL_DEFINE5(perf_event_open,
group_leader = NULL;
}
+ event = perf_event_alloc(&attr, cpu, group_leader, NULL, NULL);
+ if (IS_ERR(event)) {
+ err = PTR_ERR(event);
+ goto err_fd;
+ }
+
/*
* Special case software events and allow them to be part of
* any hardware group.
@@ -5653,7 +5653,6 @@ err_context:
put_ctx(ctx);
err_group_fd:
fput_light(group_file, fput_needed);
-err_alloc:
free_event(event);
err_fd:
put_unused_fd(event_fd);
reply other threads:[~2010-09-15 15:45 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4c90ea16.21edd80a.4b94.2495@mx.google.com \
--to=eranian@google.com \
--cc=davem@davemloft.net \
--cc=eranian@gmail.com \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=paulus@samba.org \
--cc=perfmon2-devel@lists.sf.net \
--cc=peterz@infradead.org \
--cc=robert.richter@amd.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).