On Tue, 15 Mar 2011 11:40:46 +0900 Minchan Kim <minchan.kim@xxxxxxxxx> wrote: > On Tue, Mar 15, 2011 at 11:28 AM, Andrew Morton > <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > On Tue, 15 Mar 2011 11:12:37 +0900 Minchan Kim <minchan.kim@xxxxxxxxx> wrote: > > > >> >> I can't understand why we should hanlde activate_page_pvecs specially. > >> >> Please, enlighten me. > >> > Not it's special. akpm asked me to do it this time. Reducing little > >> > memory is still worthy anyway, so that's it. We can do it for other > >> > pvecs too, in separate patch. > >> > >> Understandable but I don't like code separation by CONFIG_SMP for just > >> little bit enhance of memory usage. In future, whenever we use percpu, > >> do we have to implement each functions for both SMP and non-SMP? > >> Is it desirable? > >> Andrew, Is it really valuable? > > > > It's a little saving of text footprint. __It's also probably faster this way - > > putting all the pages into a pagevec then later processing them won't > > be very L1 cache friendly. > > > > > > I am not sure how much effective it is in UP. But if L1 cache friendly > is important concern, we should not use per-cpu about hot operation. It's not due to the percpu thing. The issue is putting 14 pages into a pagevec and then later processing them after the older ones might have fallen out of cache. > I think more important thing in embedded (normal UP), it is a lock latency. > I don't want to hold/release the lock per page. There is no lock on UP builds. -- 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>