From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3D6E8B7F.8D5D20D8@zip.com.au> Date: Thu, 29 Aug 2002 14:00:47 -0700 From: Andrew Morton MIME-Version: 1.0 Subject: Re: [PATCH] low-latency zap_page_range() References: <3D6E844C.4E756D10@zip.com.au> <1030653602.939.2677.camel@phantasy> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Robert Love Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: Robert Love wrote: > > ... > unless we > wanted to unconditionally drop the locks and let preempt just do the > right thing and also reduce SMP lock contention in the SMP case. That's an interesting point. page_table_lock is one of those locks which is occasionally held for ages, and frequently held for a short time. I suspect that yes, voluntarily popping the lock during the long holdtimes will allow other CPUs to get on with stuff, and will provide efficiency increases. (It's a pretty lame way of doing that though). But I don't recall seeing nasty page_table_lock spintimes on anyone's lockmeter reports, so we can leave it as-is for now. -- 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/