From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f71.google.com (mail-it0-f71.google.com [209.85.214.71]) by kanga.kvack.org (Postfix) with ESMTP id 6D7576B0069 for ; Fri, 16 Sep 2016 09:25:13 -0400 (EDT) Received: by mail-it0-f71.google.com with SMTP id u18so63522769ita.2 for ; Fri, 16 Sep 2016 06:25:13 -0700 (PDT) Received: from merlin.infradead.org (merlin.infradead.org. [2001:4978:20e::2]) by mx.google.com with ESMTPS id k77si13074559iod.60.2016.09.16.06.25.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 16 Sep 2016 06:25:12 -0700 (PDT) Date: Fri, 16 Sep 2016 15:25:06 +0200 From: Peter Zijlstra Subject: Re: [PATCH 1/4] mm, vmscan: Batch removal of mappings under a single lock during reclaim Message-ID: <20160916132506.GB5035@twins.programming.kicks-ass.net> References: <1473415175-20807-1-git-send-email-mgorman@techsingularity.net> <1473415175-20807-2-git-send-email-mgorman@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1473415175-20807-2-git-send-email-mgorman@techsingularity.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 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. -- 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