Files
chipyard/scripts/numa_prefix
2020-08-20 23:37:17 -07:00

68 lines
2.3 KiB
Perl
Executable File

#!/usr/bin/env perl
#============================================================================
# - really simple script, which just prints out the numactl cmd to
# prefix before your actual command. it determines this based on free
# memory size attached to every node.
# - when you run this on a machine without `numactl`, the output is empty,
# so `$(numa_prefix) <cmd> <args>` turns in to `<cmd> <args>`.
# - when the machine has `numactl` installed, regardless of the socket-count
# on the machine, the resulting command is:
# `numactl -m <socket> -C <core-id list> -- <cmd> <args>`
# - example output from `numactl -H` on a 2 socket machine:
# available: 2 nodes (0-1)
# node 0 cpus: 0 2 4 6 8 10 12 14 16 18 20 22
# node 0 size: 131026 MB
# node 0 free: 7934 MB
# node 1 cpus: 1 3 5 7 9 11 13 15 17 19 21 23
# node 1 size: 65536 MB
# node 1 free: 429 MB
# node distances:
# node 0 1
# 0: 10 20
# 1: 20 10
#============================================================================
use strict;
use warnings;
my $path = `which numactl`;
if(length($path) > 0) {
my ($head_line, @rest) = map {chomp; $_} `numactl -H`;
if($head_line =~ /available: (\d+) nodes/) {
my $node_count = $1;
my $best_node_id = undef
my $best_cpus = undef;
my $best_free_size = undef;
# loop through available nodes, selecting the node with the most free mem
foreach my $num (1..$node_count) {
my $cpus_line = shift(@rest);
my $mem_size_line = shift(@rest);
my $mem_free_line = shift(@rest);
if($cpus_line =~ /node (\d+) cpus: (\d.*\d)$/) {
my ($node_id, $cpus) = ($1, $2);
$cpus =~ s/\s+/,/g;
if($mem_free_line =~ /node $node_id free: (\d+) \S+$/) {
my $free_size = $1;
if(!defined($best_free_size) || ($free_size > $best_free_size)) {
$best_node_id = $node_id;
$best_cpus = $cpus;
$best_free_size = $free_size;
}
} else {
die("malformed mem-free line: $mem_free_line\n");
}
} else {
die("malformed cpus line: $cpus_line\n");
}
}
print("numactl -m $best_node_id -C $best_cpus --");
} else {
die("malformed head line: $head_line\n");
}
}