On Fri 02-08-13 11:07:56, Joonsoo Kim wrote: > We rarely allocate a page with ALLOC_NO_WATERMARKS and it is used > in slow path. For making fast path more faster, add likely macro to > help compiler optimization.
The code is different in mmotm tree (see mm: page_alloc: rearrange watermark checking in get_page_from_freelist) Besides that, make sure you provide numbers which prove your claims about performance optimizations. > Signed-off-by: Joonsoo Kim <iamjoonsoo....@lge.com> > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index b100255..86ad44b 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1901,7 +1901,7 @@ zonelist_scan: > goto this_zone_full; > > BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK); > - if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { > + if (likely(!(alloc_flags & ALLOC_NO_WATERMARKS))) { > unsigned long mark; > int ret; > > -- > 1.7.9.5 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majord...@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"d...@kvack.org"> em...@kvack.org </a> -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/