SVN: toys/tools/cleanbuild/fixfreq

[sparky]

Author: sparky
Date: Tue Dec  8 02:08:17 2009
New Revision: 11014

Added:
   toys/tools/cleanbuild/fixfreq   (contents, props changed)
Log:
- set cpufreq scaling governor to performance on all cores while building
  something, set to ondemand otherwise


Added: toys/tools/cleanbuild/fixfreq
==============================================================================
--- (empty file)
+++ toys/tools/cleanbuild/fixfreq	Tue Dec  8 02:08:17 2009
@@ -0,0 +1,54 @@
+#!/usr/bin/perl
+
+use Fcntl;
+my $fifo = "/tmp/fixfreq";
+
+system "mkfifo", $fifo;
+chmod 0600, $fifo;
+
+sysopen( READ_PIDS, $fifo, O_NONBLOCK|O_RDONLY) or die "Can't open modem: $!\n";
+
+
+END {
+	set( 0 );
+	close READ_PIDS;
+	unlink $fifo;
+}
+
+sub bye { exit; }
+
+$SIG{TERM} = \&bye;
+$SIG{INT} = \&bye;
+
+my $now_is = "";
+sub set
+{
+	my $num = shift;
+	my $set_to = $num ? "performance" : "ondemand";
+	return if $now_is eq $set_to;
+	$now_is = $set_to;
+	foreach my $gov ( glob "/sys/devices/system/cpu/cpu[0-9]*/cpufreq/scaling_governor" ) {
+		open GOV, ">", $gov;
+		print GOV $set_to;
+		close GOV;
+	}
+}
+
+my %pids;
+
+while ( 1 ) {
+	foreach my $pid ( keys %pids ) {
+		unless ( -d "/proc/".$pid ) {
+			delete $pids{ $pid };
+		}
+	}
+	while ( my $pid = <READ_PIDS> ) {
+		chomp $pid;
+		if ( -d "/proc/$pid" ) {
+			$pids{ $pid } = 1;
+		}
+	}
+	set( keys %pids );
+	sleep 1;
+}
+