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The following commit(s) were added to refs/heads/master by this push:
new 42323fa Script to find mutexes/futexes that are contending
42323fa is described below
commit 42323fa40c4f35ebac79ed306eb7c7e4702ec27c
Author: Bryan Call <bc...@apache.org>
AuthorDate: Fri May 8 11:50:40 2020 -0700
Script to find mutexes/futexes that are contending
---
tools/gdb_mutex_contention.pl | 101 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 101 insertions(+)
diff --git a/tools/gdb_mutex_contention.pl b/tools/gdb_mutex_contention.pl
new file mode 100755
index 0000000..bb6c164
--- /dev/null
+++ b/tools/gdb_mutex_contention.pl
@@ -0,0 +1,101 @@
+#!/usr/bin/perl
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This script requires that you run futexes.stp system tap script first
+# https://sourceware.org/systemtap/examples/#process/futexes.stp
+
+use strict;
+use warnings;
+use Getopt::Std;
+
+sub usage() {
+ print "gdb_mutex_contention.pl -f futexes_output [-s symbols] [-m
mutexes]\n";
+ print "Example:\n";
+ print "\tsudo timeout 30 ./futexes.stp > futexes.out\n";
+ print "\tsudo ./gdb_mutex_contention.pl -f futexes.out\n";
+
+ exit 1;
+}
+
+{
+ my %opts;
+ getopts('m:f:s:', \%opts);
+ usage() if (! defined$opts{f});
+
+ my $pid = 0;
+ my $file = $opts{f};
+ my $symbols = $opts{s} || 20;
+ my $mutexes = $opts{m} || 10;
+ my %locks;
+
+ # Read output from futexes.stp
+ open(INPUT, $file) || die $!;
+ while(<INPUT>) {
+ chomp;
+ if (m/(ET_NET|traffic_server).+\[(\d+)\] lock (\S+) contended (\d+) times,
(\d+) avg us/) {
+ $pid = $2;
+ my $lock = $3;
+ my $frequency = $4;
+ my $wait = $5;
+ $locks{$lock}->{frequency} = $frequency;
+ $locks{$lock}->{line} = $_;
+ $locks{$lock}->{wait} = $wait * $frequency;
+ }
+ }
+
+ # Grab the binary from the running pid
+ my $binary = `ps --pid $pid -o command -h`;
+ chomp $binary;
+
+ # Print out what we are going to run gdb on
+ print "Running gdb over binary: $binary and pid: $pid\n";
+
+ # Loop over the futexes that had the highest total wait time
+ my $count = 0;
+ foreach my $lock (sort { $locks{$b}->{wait} <=> $locks{$a}->{wait} } keys
%locks) {
+ print "lock: $locks{$lock}->{line} - total wait: $locks{$lock}->{wait}\n";
+
+ open(MACRO, "> gdb.auto.mutex.macro") || die $!;
+ print MACRO "handle SIGPIPE nostop\n";
+ print MACRO "handle SIGPIPE noprint\n\n";
+ print MACRO "rwatch *$lock\n\n";
+ print MACRO "cont\n";
+ print MACRO "bt 40\n";
+ close(MACRO);
+
+ system("gdb -x gdb.auto.mutex.macro --batch $binary $pid >& gdb.out");
+
+ open(GDB_OUT, "gdb.out") || die $!;
+ my $gdb_out_lines = 1;
+ while (<GDB_OUT>) {
+ chomp;
+ if (m|\#\d+ (.+)|) {
+ print "\t$_\n";
+ last if ++$gdb_out_lines > $symbols;
+ }
+
+ }
+ close(GDB_OUT);
+ last if ++$count > $mutexes;
+ print "\n";
+ }
+
+ unlink("gdb.auto.mutex.macro");
+ unlink("gdb.out");
+ close(INPUT);
+}
