From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e36.co.us.ibm.com (8.13.8/8.13.8) with ESMTP id l99L2rC7026019 for ; Tue, 9 Oct 2007 17:02:53 -0400 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v8.5) with ESMTP id l99L2j37367480 for ; Tue, 9 Oct 2007 15:02:49 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l99L2iEJ021513 for ; Tue, 9 Oct 2007 15:02:45 -0600 Subject: Re: [rfc] more granular page table lock for hugepages From: Badari Pulavarty In-Reply-To: References: <20071008225234.GC27824@linux-os.sc.intel.com> Content-Type: text/plain Date: Tue, 09 Oct 2007 14:05:57 -0700 Message-Id: <1191963958.12131.43.camel@dyn9047017100.beaverton.ibm.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Ken Chen Cc: "Siddha, Suresh B" , linux-mm List-ID: On Tue, 2007-10-09 at 13:23 -0700, Ken Chen wrote: > On 10/8/07, Siddha, Suresh B wrote: > > Appended patch is a quick prototype which extends the concept of separate > > spinlock per page table page to hugepages. More granular spinlock will > > be used to guard the page table entries in the pmd page, instead of using the > > mm's single page_table_lock. > > What path do you content on mm->page_table_lock? > > The major fault for hugetlb page is blanket by > hugetlb_instantiation_mutex. So likelihood of contention on > page_table spin lock is low. For minor fault, I would think > mapping->i_mmap_lock will kick in before page table lock. That left > follow_hugetlb_page path. Is it the case? Yes. follow_hugetlb_page() is where our benchmark team has seen contention with threaded workload. Thanks, Badari -- 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