Messages in this thread | | | Date | Fri, 4 Nov 2005 09:38:33 -0800 | From | Andrew Morton <> | Subject | Re: [Lhms-devel] [PATCH 0/7] Fragmentation Avoidance V19 |
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"Martin J. Bligh" <mbligh@mbligh.org> wrote: > > > Seriously, it does appear that doing it per-task is adequate for your > > needs, and it is certainly more general. > > > > > > > > I cannot understand why you decided to count only the number of > > direct-reclaim events, via a "digitally filtered, constant time based, > > event frequency meter". > > > > a) It loses information. If we were to export the number of pages > > reclaimed from the mm, filtering can be done in userspace. > > > > b) It omits reclaim performed by kswapd and by other tasks (ok, it's > > very cpuset-specific). > > > > c) It only counts synchronous try_to_free_pages() attempts. What if an > > attempt only freed pagecache, or didbn't manage to free anything? > > > > d) It doesn't notice if kswapd is swapping the heck out of your > > not-allocating-any-memory-now process. > > > > > > I think all the above can be addressed by exporting per-task (actually > > per-mm) reclaim info. (I haven't put much though into what info that > > should be - page reclaim attempts, mmapped reclaims, swapcache reclaims, > > etc) > > I've been looking at similar things. When we page out / free something from > a shared library that 10 tasks have mapped, who does that count against > for pressure?
Count pte unmappings and minor faults and account them against the mm_struct, I guess. - 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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