From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: + mm-more-likely-reclaim-madv_sequential-mappings.patch added to -mm tree Date: Tue, 11 Nov 2008 16:00:51 -0800 Message-ID: <200811120000.mAC00pOf030889@imap1.linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:54617 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751458AbYKLABv (ORCPT ); Tue, 11 Nov 2008 19:01:51 -0500 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: mm-commits@vger.kernel.org Cc: hannes@cmpxchg.org, hannes@saeurebad.de, kosaki.motohiro@jp.fujitsu.com, npiggin@suse.de, riel@redhat.com The patch titled mm: more likely reclaim MADV_SEQUENTIAL mappings has been added to the -mm tree. Its filename is mm-more-likely-reclaim-madv_sequential-mappings.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: mm: more likely reclaim MADV_SEQUENTIAL mappings From: Johannes Weiner File pages mapped only in sequentially read mappings are perfect reclaim canditates. This patch makes these mappings behave like weak references, their pages will be reclaimed unless they have a strong reference from a normal mapping as well. It changes the reclaim and the unmap path where they check if the page has been referenced. In both cases, accesses through sequentially read mappings will be ignored. Benchmark results from KOSAKI Motohiro: http://marc.info/?l=linux-mm&m=122485301925098&w=2 Signed-off-by: Johannes Weiner Signed-off-by: Rik van Riel Acked-by: KOSAKI Motohiro Cc: Nick Piggin Signed-off-by: Andrew Morton --- mm/memory.c | 3 ++- mm/rmap.c | 13 +++++++++++-- 2 files changed, 13 insertions(+), 3 deletions(-) diff -puN mm/memory.c~mm-more-likely-reclaim-madv_sequential-mappings mm/memory.c --- a/mm/memory.c~mm-more-likely-reclaim-madv_sequential-mappings +++ a/mm/memory.c @@ -757,7 +757,8 @@ static unsigned long zap_pte_range(struc else { if (pte_dirty(ptent)) set_page_dirty(page); - if (pte_young(ptent)) + if (pte_young(ptent) && + likely(!VM_SequentialReadHint(vma))) mark_page_accessed(page); file_rss--; } diff -puN mm/rmap.c~mm-more-likely-reclaim-madv_sequential-mappings mm/rmap.c --- a/mm/rmap.c~mm-more-likely-reclaim-madv_sequential-mappings +++ a/mm/rmap.c @@ -360,8 +360,17 @@ static int page_referenced_one(struct pa goto out_unmap; } - if (ptep_clear_flush_young_notify(vma, address, pte)) - referenced++; + if (ptep_clear_flush_young_notify(vma, address, pte)) { + /* + * Don't treat a reference through a sequentially read + * mapping as such. If the page has been used in + * another mapping, we will catch it; if this other + * mapping is already gone, the unmap path will have + * set PG_referenced or activated the page. + */ + if (likely(!VM_SequentialReadHint(vma))) + referenced++; + } /* Pretend the page is referenced if the task has the swap token and is in the middle of a page fault. */ _ Patches currently in -mm which might be from hannes@cmpxchg.org are mm-more-likely-reclaim-madv_sequential-mappings.patch