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[3.16.y-ckt,stable] Patch "perf hists browser: Take the --comm, --dsos, etc filters into account" has been added to staging queue

Message ID 1439297759-30606-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques Aug. 11, 2015, 12:55 p.m. UTC
This is a note to let you know that I have just added a patch titled

    perf hists browser: Take the --comm, --dsos, etc filters into account

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt16.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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From 6bf9964d1b716ed37a5cb97c47d808e18683fb9c Mon Sep 17 00:00:00 2001
From: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Mon, 13 Jul 2015 08:26:35 -0300
Subject: perf hists browser: Take the --comm, --dsos, etc filters into account

commit 9c0fa8dd3d58de8b688fda758eea1719949c7f0a upstream.

At some point:

  commit 2c86c7ca7606
  Author: Namhyung Kim <namhyung@kernel.org>
  Date:   Mon Mar 17 18:18:54 2014 -0300

    perf report: Merge al->filtered with hist_entry->filtered

We stopped dropping samples for things filtered via the --comms, --dsos,
--symbols, etc, i.e. things marked as filtered in the symbol resolution
routines (thread__find_addr_map(), perf_event__preprocess_sample(),
etc).

But then, in:

  commit 268397cb2a47
  Author: Namhyung Kim <namhyung@kernel.org>
  Date:   Tue Apr 22 14:49:31 2014 +0900

    perf top/tui: Update nr_entries properly after a filter is applied

We don't take into account entries that were filtered in
perf_event__preprocess_sample() and friends, which leads to
inconsistency in the browser seek routines, that expects the number of
hist_entry->filtered entries to match what it thinks is the number of
unfiltered, browsable entries.

So, for instance, when we do:

  perf top --symbols ___non_existent_symbol___

the hist_browser__nr_entries() routine thinks there are no filters in
place, uses the hists->nr_entries but all entries are filtered, leading
to a segfault.

Tested with:

   perf top --symbols malloc,free --percentage=relative

Freezing, by pressing 'f', at any time and doing the math on the
percentages ends up with 100%, ditto for:

   perf top --dsos libpthread-2.20.so,libxul.so --percentage=relative

Both were segfaulting, all fixed now.

More work needed to do away with checking if filters are in place, we
should just use the nr_non_filtered_samples counter, no need to
conditionally use it or hists.nr_filter, as what the browser does is
just show unfiltered stuff. An audit of how it is being accounted is
needed, this is the minimal fix.

Reported-by: Michael Petlan <mpetlan@redhat.com>
Fixes: 268397cb2a47 ("perf top/tui: Update nr_entries properly after a filter is applied")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-6w01d5q97qk0d64kuojme5in@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 tools/perf/ui/browsers/hists.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox

Patch

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 04a229aa5c0f..868993d355e0 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -42,7 +42,7 @@  static struct rb_node *hists__filter_entries(struct rb_node *nd,

 static bool hist_browser__has_filter(struct hist_browser *hb)
 {
-	return hists__has_filter(hb->hists) || hb->min_pcnt;
+	return hists__has_filter(hb->hists) || hb->min_pcnt || symbol_conf.has_filter;
 }

 static u32 hist_browser__nr_entries(struct hist_browser *hb)