Revision 59a32e2ce5eb809967cac4e718bc527beca83c59 authored by Eric Dumazet on 23 March 2012, 22:02:53 UTC, committed by Linus Torvalds on 23 March 2012, 23:58:42 UTC
On a typical 16 cpus machine, "cat /proc/stat" gives more than 4096 bytes, and is slow : # strace -T -o /tmp/STRACE cat /proc/stat | wc -c 5826 # grep "cpu " /tmp/STRACE read(0, "cpu 1949310 19 2144714 12117253"..., 32768) = 5826 <0.001504> Thats partly because show_stat() must be called twice since initial buffer size is too small (4096 bytes for less than 32 possible cpus) Fix this by : 1) Taking into account nr_irqs in the initial buffer sizing. 2) Using ksize() to allow better filling of initial buffer. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Russell King - ARM Linux <linux@arm.linux.org.uk> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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headers_install.pl
#!/usr/bin/perl -w
#
# headers_install prepare the listed header files for use in
# user space and copy the files to their destination.
#
# Usage: headers_install.pl readdir installdir arch [files...]
# readdir: dir to open files
# installdir: dir to install the files
# arch: current architecture
# arch is used to force a reinstallation when the arch
# changes because kbuild then detect a command line change.
# files: list of files to check
#
# Step in preparation for users space:
# 1) Drop all use of compiler.h definitions
# 2) Drop include of compiler.h
# 3) Drop all sections defined out by __KERNEL__ (using unifdef)
use strict;
my ($readdir, $installdir, $arch, @files) = @ARGV;
my $unifdef = "scripts/unifdef -U__KERNEL__ -D__EXPORTED_HEADERS__";
foreach my $file (@files) {
my $tmpfile = "$installdir/$file.tmp";
open(my $in, '<', "$readdir/$file")
or die "$readdir/$file: $!\n";
open(my $out, '>', $tmpfile)
or die "$tmpfile: $!\n";
while (my $line = <$in>) {
$line =~ s/([\s(])__user\s/$1/g;
$line =~ s/([\s(])__force\s/$1/g;
$line =~ s/([\s(])__iomem\s/$1/g;
$line =~ s/\s__attribute_const__\s/ /g;
$line =~ s/\s__attribute_const__$//g;
$line =~ s/\b__packed\b/__attribute__((packed))/g;
$line =~ s/^#include <linux\/compiler.h>//;
$line =~ s/(^|\s)(inline)\b/$1__$2__/g;
$line =~ s/(^|\s)(asm)\b(\s|[(]|$)/$1__$2__$3/g;
$line =~ s/(^|\s|[(])(volatile)\b(\s|[(]|$)/$1__$2__$3/g;
printf {$out} "%s", $line;
}
close $out;
close $in;
system $unifdef . " $tmpfile > $installdir/$file";
# unifdef will exit 0 on success, and will exit 1 when the
# file was processed successfully but no changes were made,
# so abort only when it's higher than that.
my $e = $? >> 8;
if ($e > 1) {
die "$tmpfile: $!\n";
}
unlink $tmpfile;
}
exit 0;
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