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>
1 parent b908243
config
#!/bin/bash
# Manipulate options in a .config file from the command line
usage() {
cat >&2 <<EOL
Manipulate options in a .config file from the command line.
Usage:
config options command ...
commands:
--enable|-e option Enable option
--disable|-d option Disable option
--module|-m option Turn option into a module
--set-str option string
Set option to "string"
--set-val option value
Set option to value
--state|-s option Print state of option (n,y,m,undef)
--enable-after|-E beforeopt option
Enable option directly after other option
--disable-after|-D beforeopt option
Disable option directly after other option
--module-after|-M beforeopt option
Turn option into module directly after other option
commands can be repeated multiple times
options:
--file .config file to change (default .config)
config doesn't check the validity of the .config file. This is done at next
make time.
EOL
exit 1
}
checkarg() {
ARG="$1"
if [ "$ARG" = "" ] ; then
usage
fi
case "$ARG" in
CONFIG_*)
ARG="${ARG/CONFIG_/}"
;;
esac
ARG="`echo $ARG | tr a-z A-Z`"
}
set_var() {
local name=$1 new=$2 before=$3
name_re="^($name=|# $name is not set)"
before_re="^($before=|# $before is not set)"
if test -n "$before" && grep -Eq "$before_re" "$FN"; then
sed -ri "/$before_re/a $new" "$FN"
elif grep -Eq "$name_re" "$FN"; then
sed -ri "s:$name_re.*:$new:" "$FN"
else
echo "$new" >>"$FN"
fi
}
if [ "$1" = "--file" ]; then
FN="$2"
if [ "$FN" = "" ] ; then
usage
fi
shift 2
else
FN=.config
fi
if [ "$1" = "" ] ; then
usage
fi
while [ "$1" != "" ] ; do
CMD="$1"
shift
case "$CMD" in
--refresh)
;;
--*-after)
checkarg "$1"
A=$ARG
checkarg "$2"
B=$ARG
shift 2
;;
-*)
checkarg "$1"
shift
;;
esac
case "$CMD" in
--enable|-e)
set_var "CONFIG_$ARG" "CONFIG_$ARG=y"
;;
--disable|-d)
set_var "CONFIG_$ARG" "# CONFIG_$ARG is not set"
;;
--module|-m)
set_var "CONFIG_$ARG" "CONFIG_$ARG=m"
;;
--set-str)
set_var "CONFIG_$ARG" "CONFIG_$ARG=\"$1\""
shift
;;
--set-val)
set_var "CONFIG_$ARG" "CONFIG_$ARG=$1"
shift
;;
--state|-s)
if grep -q "# CONFIG_$ARG is not set" $FN ; then
echo n
else
V="$(grep "^CONFIG_$ARG=" $FN)"
if [ $? != 0 ] ; then
echo undef
else
V="${V/CONFIG_$ARG=/}"
V="${V/\"/}"
echo "$V"
fi
fi
;;
--enable-after|-E)
set_var "CONFIG_$B" "CONFIG_$B=y" "CONFIG_$A"
;;
--disable-after|-D)
set_var "CONFIG_$B" "# CONFIG_$B is not set" "CONFIG_$A"
;;
--module-after|-M)
set_var "CONFIG_$B" "CONFIG_$B=m" "CONFIG_$A"
;;
# undocumented because it ignores --file (fixme)
--refresh)
yes "" | make oldconfig
;;
*)
usage
;;
esac
done
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