On Tue, Apr 28, 2015 at 12:05:19PM +0200, Michal Marek wrote: > On 2015-04-28 10:57, Riku Voipio wrote: > > On 27 April 2015 at 19:43, Chris J Arges <chris.j.arges@xxxxxxxxxxxxx> wrote: > >> When building the dbg package, we use a large 'for module in $(find' loop that > >> can be easily parallelized by using 'find | xargs'. This patch modifies this > >> loop to use the later paradigm. > >> > >> In addition, ensure we add '-n1 -P0' to xargs to run as many processes as > >> possible. > >> > >> Signed-off-by: Chris J Arges <chris.j.arges@xxxxxxxxxxxxx> > >> --- > >> scripts/package/builddeb | 15 ++++++++------- > >> 1 file changed, 8 insertions(+), 7 deletions(-) > >> > >> diff --git a/scripts/package/builddeb b/scripts/package/builddeb > >> index 88dbf23..538f829 100755 > >> --- a/scripts/package/builddeb > >> +++ b/scripts/package/builddeb > >> @@ -152,16 +152,17 @@ if grep -q '^CONFIG_MODULES=y' $KCONFIG_CONFIG ; then > >> rmdir "$tmpdir/lib/modules/$version" > >> fi > >> if [ -n "$BUILD_DEBUG" ] ; then > >> - for module in $(find $tmpdir/lib/modules/ -name *.ko -printf '%P\n'); do > >> - module=lib/modules/$module > >> - mkdir -p $(dirname $dbg_dir/usr/lib/debug/$module) > >> + find $tmpdir/lib/modules/ -name *.ko -printf '%P\n' | xargs -n1 -P0 -I {} sh -c ' > > > > I would go with -P`getconf _NPROCESSORS_ONLN`. There can be thousands > > of modules (allmodconfig will make 4500). > > Yep. I was thinking about retrieving the value of the make -j argument > somehow, but this is not possible and we certainly do not want to > implement the jobserver protocol in shell :-). So using the number of > processors is a sensible choice. What can be done is to detect whether > the -j option is in MAKEFLAGS and only then use multiple instances. > > Michal > Michal, The MAKEFLAGS variable will have the jobserver fd's in it, if we are building in parallel with -j. I could use this to detect if we are building in parallel and adjust the '-P' flag in xargs accordingly. I'll work on v3 of this patch, thanks for the reviews! --chris -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html