Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-24 05:02:12 +00:00
Code Issues Packages Projects Releases Wiki Activity

perf perl scripts: Fix SIGALRM and pipe read race for rwtop

Browse Source 
Fixing rwtop script race. The issue is caused by rwtop script triggering
SIGALRM and underneath pipe reading layer reporting error when
interrupted.

Fixing this by setting SA_RESTART for rwtop SIGALRM handler, which
avoids interruption of the pipe reading layer.

The discussion for this issue & fix is here:
https://lkml.org/lkml/2012/9/18/123

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Original-patch-by: Andrew Jones <drjones@redhat.com>
Cc: Andrew Jones <drjones@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1360080351-3246-2-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jiri Olsa 2013-02-05 17:05:50 +01:00 committed by Arnaldo Carvalho de Melo
parent 0c5268bf22
commit b22e79395c
1 changed files with 5 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
tools/perf/scripts/perl/rwtop.pl
View File

@ -17,6 +17,7 @@ use lib "$ENV{'PERF_EXEC_PATH'}/scripts/perl/Perf-Trace-Util/lib";
use lib "./Perf-Trace-Util/lib";
use Perf::Trace::Core;
use Perf::Trace::Util;
use POSIX qw/SIGALRM SA_RESTART/;
my $default_interval = 3;
my $nlines = 20;
@ -90,7 +91,10 @@ sub syscalls::sys_enter_write
sub trace_begin
{
$SIG{ALRM} = \&set_print_pending;
my $sa = POSIX::SigAction->new(\&set_print_pending);
$sa->flags(SA_RESTART);
$sa->safe(1);
POSIX::sigaction(SIGALRM, $sa) or die "Can't set SIGALRM handler: $!\n";
alarm 1;
}