From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id 6EE4C6B0055 for ; Mon, 17 Aug 2009 16:28:19 -0400 (EDT) Subject: Re: Discard support (was Re: [PATCH] swap: send callback when swap slot is freed) From: James Bottomley In-Reply-To: <4A89BB5B.5060403@rtr.ca> References: <200908122007.43522.ngupta@vflare.org> <20090816083434.2ce69859@infradead.org> <1250437927.3856.119.camel@mulgrave.site> <4A8834B6.2070104@rtr.ca> <1250446047.3856.273.camel@mulgrave.site> <4A884D9C.3060603@rtr.ca> <1250447052.3856.294.camel@mulgrave.site> <4A898752.9000205@tmr.com> <87f94c370908171008t44ff64ack2153e740128278e@mail.gmail.com> <1250529575.7858.31.camel@mulgrave.site> <87f94c370908171121u5ee8016p253824b16851b48@mail.gmail.com> <1250536709.7858.43.camel@mulgrave.site> <4A89BB5B.5060403@rtr.ca> Content-Type: text/plain Date: Mon, 17 Aug 2009 15:28:12 -0500 Message-Id: <1250540892.7858.59.camel@mulgrave.site> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Mark Lord Cc: Greg Freemyer , Bill Davidsen , Arjan van de Ven , Alan Cox , Chris Worley , Matthew Wilcox , Bryan Donlan , david@lang.hm, Markus Trippelsdorf , Matthew Wilcox , Hugh Dickins , Nitin Gupta , Ingo Molnar , Peter Zijlstra , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org, Linux RAID List-ID: On Mon, 2009-08-17 at 16:19 -0400, Mark Lord wrote: > James Bottomley wrote: > > On Mon, 2009-08-17 at 14:21 -0400, Greg Freemyer wrote: > >> On Mon, Aug 17, 2009 at 1:19 PM, James Bottomley wrote: > >>> On Mon, 2009-08-17 at 13:08 -0400, Greg Freemyer wrote: > .. > >>>> Non-coalescing is believed detrimental, > >>> It is? Why? > >> For the only compliant SSD in the wild, Mark has shown it to be true > >> via testing. > > > > He only said larger trims take longer. As I said previously, if it's a > > X+nY relationship, then we still benefit from accumulation up to some > > value of n. > .. > > Err, what I said was, "rm -rf /usr/src/linux" takes over half an hour > with uncoalesced TRIM, and only a scant few seconds in total *with* > coalesced TRIM. Yes, sorry, missed the Non- when I read that sentence. James -- 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