Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754348Ab3IPOgk (ORCPT ); Mon, 16 Sep 2013 10:36:40 -0400 Received: from e28smtp03.in.ibm.com ([122.248.162.3]:41984 "EHLO e28smtp03.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752911Ab3IPOgj (ORCPT ); Mon, 16 Sep 2013 10:36:39 -0400 From: "Aneesh Kumar K.V" To: Naoya Horiguchi , linux-mm@kvack.org, Andrew Morton Cc: Alex Thorlton , Mel Gorman , Andi Kleen , Michal Hocko , KOSAKI Motohiro , Rik van Riel , Andrea Arcangeli , kirill.shutemov@linux.intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4] hugetlbfs: support split page table lock In-Reply-To: <1379117362-gwv3vrog-mutt-n-horiguchi@ah.jp.nec.com> References: <1379117362-gwv3vrog-mutt-n-horiguchi@ah.jp.nec.com> User-Agent: Notmuch/0.16+32~g01f5508 (http://notmuchmail.org) Emacs/24.3.50.1 (x86_64-unknown-linux-gnu) Date: Mon, 16 Sep 2013 20:06:30 +0530 Message-ID: <878uywbzpt.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13091614-3864-0000-0000-00000A186E51 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1569 Lines: 39 Naoya Horiguchi writes: > Hi, > > Kirill posted split_ptl patchset for thp today, so in this version > I post only hugetlbfs part. I added Kconfig variables in following > Kirill's patches (although without CONFIG_SPLIT_*_PTLOCK_CPUS.) > > This patch changes many lines, but all are in hugetlbfs specific code, > so I think we can apply this independent of thp patches. > ----- > From: Naoya Horiguchi > Date: Fri, 13 Sep 2013 18:12:30 -0400 > Subject: [PATCH v4] hugetlbfs: support split page table lock > > Currently all of page table handling by hugetlbfs code are done under > mm->page_table_lock. So when a process have many threads and they heavily > access to the memory, lock contention happens and impacts the performance. > > This patch makes hugepage support split page table lock so that we use > page->ptl of the leaf node of page table tree which is pte for normal pages > but can be pmd and/or pud for hugepages of some architectures. > > ChangeLog v4: > - introduce arch dependent macro ARCH_ENABLE_SPLIT_HUGETLB_PTLOCK > (only defined for x86 for now) > - rename USE_SPLIT_PTLOCKS_HUGETLB to USE_SPLIT_HUGETLB_PTLOCKS Can we have separate locking for THP and hugetlb ? Doesn't both require us to use same locking when updating pmd ? -aneesh -- 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/