From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f72.google.com (mail-pa0-f72.google.com [209.85.220.72]) by kanga.kvack.org (Postfix) with ESMTP id 13F006B0253 for ; Fri, 16 Sep 2016 10:07:12 -0400 (EDT) Received: by mail-pa0-f72.google.com with SMTP id fu14so87328844pad.0 for ; Fri, 16 Sep 2016 07:07:12 -0700 (PDT) Received: from bombadil.infradead.org (bombadil.infradead.org. [2001:1868:205::9]) by mx.google.com with ESMTPS id m66si45316548pfc.281.2016.09.16.07.07.11 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 16 Sep 2016 07:07:11 -0700 (PDT) Date: Fri, 16 Sep 2016 16:07:07 +0200 From: Peter Zijlstra Subject: Re: [PATCH 1/4] mm, vmscan: Batch removal of mappings under a single lock during reclaim Message-ID: <20160916140707.GI5020@twins.programming.kicks-ass.net> References: <1473415175-20807-1-git-send-email-mgorman@techsingularity.net> <1473415175-20807-2-git-send-email-mgorman@techsingularity.net> <20160916132506.GB5035@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160916132506.GB5035@twins.programming.kicks-ass.net> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: LKML , Linux-MM , Dave Chinner , Linus Torvalds , Ying Huang , Michal Hocko On Fri, Sep 16, 2016 at 03:25:06PM +0200, Peter Zijlstra wrote: > On Fri, Sep 09, 2016 at 10:59:32AM +0100, Mel Gorman wrote: > > Pages unmapped during reclaim acquire/release the mapping->tree_lock for > > every single page. There are two cases when it's likely that pages at the > > tail of the LRU share the same mapping -- large amounts of IO to/from a > > single file and swapping. This patch acquires the mapping->tree_lock for > > multiple page removals. > > So, once upon a time, in a galaxy far away,.. I did a concurrent > pagecache patch set that replaced the tree_lock with a per page bit- > spinlock and fine grained locking in the radix tree. > > I know the mm has changed quite a bit since, but would such an approach > still be feasible? > > I cannot seem to find an online reference to a 'complete' version of > that patch set, but I did find the OLS paper on it and I did find some > copies on my local machines. https://www.kernel.org/doc/ols/2007/ols2007v2-pages-311-318.pdf -- 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