Commit-ID: b22e79395c0fe4c86dd35745a929366034386ccc Gitweb: http://git.kernel.org/tip/b22e79395c0fe4c86dd35745a929366034386ccc Author: Jiri Olsa <[email protected]> AuthorDate: Tue, 5 Feb 2013 17:05:50 +0100 Committer: Arnaldo Carvalho de Melo <[email protected]> CommitDate: Wed, 6 Feb 2013 18:09:27 -0300
perf perl scripts: Fix SIGALRM and pipe read race for rwtop 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 <[email protected]> Original-patch-by: Andrew Jones <[email protected]> Cc: Andrew Jones <[email protected]> Cc: Corey Ashford <[email protected]> Cc: David Ahern <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/perf/scripts/perl/rwtop.pl | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/perf/scripts/perl/rwtop.pl b/tools/perf/scripts/perl/rwtop.pl index 4bb3ecd..8b20787 100644 --- a/tools/perf/scripts/perl/rwtop.pl +++ b/tools/perf/scripts/perl/rwtop.pl @@ -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; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
