Messages in this thread | | | Date | Thu, 10 Feb 2011 22:38:59 +0900 | Subject | Re: [RFC PATCH] mm: handle simple case in free_pcppages_bulk() | From | Minchan Kim <> |
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On Thu, Feb 10, 2011 at 10:18 PM, Namhyung Kim <namhyung@gmail.com> wrote: > 2011-02-10 (목), 22:10 +0900, Minchan Kim: >> Hello Namhyung, >> > > Hi Minchan, > > >> On Thu, Feb 10, 2011 at 8:46 PM, Namhyung Kim <namhyung@gmail.com> 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. I think if you want it really, we might need some number. I am not sure it's worth.
-- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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