Messages in this thread | | | Date | Thu, 22 Nov 2012 23:53:18 +0800 | From | Fengguang Wu <> | Subject | Re: Problem in Page Cache Replacement |
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On Thu, Nov 22, 2012 at 11:41:07PM +0800, Fengguang Wu wrote: > On Wed, Nov 21, 2012 at 12:07:22PM +0200, Metin Döşlü wrote: > > On Wed, Nov 21, 2012 at 12:00 PM, Jaegeuk Hanse <jaegeuk.hanse@gmail.com> wrote: > > > > > > On 11/21/2012 05:58 PM, metin d wrote: > > > > > > Hi Fengguang, > > > > > > I run tests and attached the results. The line below I guess shows the data-1 page caches. > > > > > > 0x000000080000006c 6584051 25718 __RU_lA___________________P________ referenced,uptodate,lru,active,private > > > > > > > > > I thinks this is just one state of page cache pages. > > > > But why these page caches are in this state as opposed to other page > > caches. From the results I conclude that: > > > > data-1 pages are in state : referenced,uptodate,lru,active,private > > I wonder if it's this code that stops data-1 pages from being > reclaimed: > > shrink_page_list(): > > if (page_has_private(page)) { > if (!try_to_release_page(page, sc->gfp_mask)) > goto activate_locked; > > What's the filesystem used?
Ah it's more likely caused by this logic:
if (is_active_lru(lru)) { if (inactive_list_is_low(mz, file)) shrink_active_list(nr_to_scan, mz, sc, priority, file);
The active file list won't be scanned at all if it's smaller than the active list. In this case, it's inactive=33586MB > active=25719MB. So the data-1 pages in the active list will never be scanned and reclaimed.
> > data-2 pages are in state : referenced,uptodate,lru,mappedtodisk > > Thanks, > Fengguang -- 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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