On Wed, Oct 18, 2017 at 08:28:56AM +0200, Vlastimil Babka wrote: > On 10/18/2017 03:53 AM, Lu, Aaron wrote: > > On Tue, 2017-10-17 at 13:32 +0200, Vlastimil Babka wrote: > >> With gcc 7.2.1: > >>> ./scripts/bloat-o-meter base.o mm/page_alloc.o > >> > >> add/remove: 1/2 grow/shrink: 2/0 up/down: 2493/-1649 (844) > > > > Nice, it clearly showed 844 bytes bloat. > > > >> function old new delta > >> get_page_from_freelist 2898 4937 +2039 > >> steal_suitable_fallback - 365 +365 > >> find_suitable_fallback 31 120 +89 > >> find_suitable_fallback.part 115 - -115 > >> __rmqueue 1534 - -1534 > > It also shows that steal_suitable_fallback() is no longer inlined. Which > is fine, because that should ideally be rarely executed.
Ah right, so this script is really good for analysing inline changes. > > >> > >>> [aaron@aaronlu obj]$ size */*/vmlinux > >>> text data bss dec hex filename > >>> 10342757 5903208 17723392 33969357 20654cd gcc-4.9.4/base/vmlinux > >>> 10342757 5903208 17723392 33969357 20654cd gcc-4.9.4/head/vmlinux > >>> 10332448 5836608 17715200 33884256 2050860 gcc-5.5.0/base/vmlinux > >>> 10332448 5836608 17715200 33884256 2050860 gcc-5.5.0/head/vmlinux > >>> 10094546 5836696 17715200 33646442 201676a gcc-6.4.0/base/vmlinux > >>> 10094546 5836696 17715200 33646442 201676a gcc-6.4.0/head/vmlinux > >>> 10018775 5828732 17715200 33562707 2002053 gcc-7.2.0/base/vmlinux > >>> 10018775 5828732 17715200 33562707 2002053 gcc-7.2.0/head/vmlinux > >>> > >>> Text size for vmlinux has no change though, probably due to function > >>> alignment. > >> > >> Yep that's useless to show. These differences do add up though, until > >> they eventually cross the alignment boundary. > > > > Agreed. > > But you know, it is the hot path, the performance improvement might be > > worth it. > > I'd agree, so you can add > > Acked-by: Vlastimil Babka <vba...@suse.cz> Thanks!
