From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx114.postini.com [74.125.245.114]) by kanga.kvack.org (Postfix) with SMTP id 3BA6C6B0068 for ; Thu, 11 Oct 2012 14:44:57 -0400 (EDT) Date: Thu, 11 Oct 2012 19:44:53 +0100 From: Mel Gorman Subject: Re: [PATCH 23/33] autonuma: retain page last_nid information in khugepaged Message-ID: <20121011184453.GG3317@csn.ul.ie> References: <1349308275-2174-1-git-send-email-aarcange@redhat.com> <1349308275-2174-24-git-send-email-aarcange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1349308275-2174-24-git-send-email-aarcange@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Linus Torvalds , Andrew Morton , Peter Zijlstra , Ingo Molnar , Hugh Dickins , Rik van Riel , Johannes Weiner , Hillf Danton , Andrew Jones , Dan Smith , Thomas Gleixner , Paul Turner , Christoph Lameter , Suresh Siddha , Mike Galbraith , "Paul E. McKenney" , Lai Jiangshan , Bharata B Rao , Lee Schermerhorn , Srivatsa Vaddagiri , Alex Shi , Mauricio Faria de Oliveira , Konrad Rzeszutek Wilk , Don Morris , Benjamin Herrenschmidt On Thu, Oct 04, 2012 at 01:51:05AM +0200, Andrea Arcangeli wrote: > When pages are collapsed try to keep the last_nid information from one > of the original pages. > If two pages within a THP disagree on the node, should the collapsing be aborted? I would expect that the code of a remote access exceeds the gain from reduced TLB overhead. > Signed-off-by: Andrea Arcangeli > --- > mm/huge_memory.c | 14 ++++++++++++++ > 1 files changed, 14 insertions(+), 0 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 1023e67..78b2851 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -1846,6 +1846,9 @@ static bool __collapse_huge_page_copy(pte_t *pte, struct page *page, > { > pte_t *_pte; > bool mknuma = false; > +#ifdef CONFIG_AUTONUMA > + int autonuma_last_nid = -1; > +#endif > for (_pte = pte; _pte < pte+HPAGE_PMD_NR; _pte++) { > pte_t pteval = *_pte; > struct page *src_page; > @@ -1855,6 +1858,17 @@ static bool __collapse_huge_page_copy(pte_t *pte, struct page *page, > add_mm_counter(vma->vm_mm, MM_ANONPAGES, 1); > } else { > src_page = pte_page(pteval); > +#ifdef CONFIG_AUTONUMA > + /* pick the first one, better than nothing */ > + if (autonuma_last_nid < 0) { > + autonuma_last_nid = > + ACCESS_ONCE(src_page-> > + autonuma_last_nid); > + if (autonuma_last_nid >= 0) > + ACCESS_ONCE(page->autonuma_last_nid) = > + autonuma_last_nid; > + } > +#endif > copy_user_highpage(page, src_page, address, vma); > VM_BUG_ON(page_mapcount(src_page) != 1); > release_pte_page(src_page); > -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org