On Thu, Feb 10, 2011 at 10:38:59PM +0900, Minchan Kim wrote: > On Thu, Feb 10, 2011 at 10:18 PM, Namhyung Kim <namhyung@xxxxxxxxx> wrote: > > 2011-02-10 (???), 22:10 +0900, Minchan Kim: > >> Hello Namhyung, > >> > > > > Hi Minchan, > > > > > >> On Thu, Feb 10, 2011 at 8:46 PM, Namhyung Kim <namhyung@xxxxxxxxx> wrote: > >> > Now I'm seeing that there are some cases to free all pages in a > >> > pcp lists. In that case, just frees all pages in the lists instead > >> > of being bothered with round-robin lists traversal. > >> > >> I though about that but I didn't send the patch. > >> That's because many cases which calls free_pcppages_bulk(, > >> pcp->count,..) are slow path so it adds comparison overhead on fast > >> path while it loses the effectiveness in slow path. > >> > > > > Hmm.. How about adding unlikely() then? Doesn't it help much here? > > Yes. It would help but I am not sure how much it is. > AFAIR, when Mel submit the patch, he tried to prove the effectiveness > with some experiment and profiler. Yep. Principally I *think* used netperf running UDP_STREAM for different buffer sizes and compared oprofile output but I also ran a battery of benchmarks to check for any other unexpected regression without profiling. -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>