From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrei Warkentin Subject: Re: [RFC 4/5] MMC: Adjust unaligned write accesses. Date: Sun, 13 Mar 2011 08:00:04 -0500 Message-ID: References: <1299718449-15172-1-git-send-email-andreiw@motorola.com> <201103102254.02041.arnd@arndb.de> <201103111123.21063.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: Received: from exprod5og103.obsmtp.com ([64.18.0.145]:33220 "EHLO exprod5og103.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755333Ab1CMNAI (ORCPT ); Sun, 13 Mar 2011 09:00:08 -0400 Received: from DE01MGRG01.AM.MOT-MOBILITY.COM ([10.22.94.167]) by DE01MGRG01.AM.MOT-MOBILITY.COM (8.14.3/8.14.3) with ESMTP id p2DD0NGR010580 for ; Sun, 13 Mar 2011 09:00:23 -0400 (EDT) Received: from mail-iy0-f170.google.com (mail-iy0-f170.google.com [209.85.210.170]) by DE01MGRG01.AM.MOT-MOBILITY.COM (8.14.3/8.14.3) with ESMTP id p2DD0MRR010577 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=OK) for ; Sun, 13 Mar 2011 09:00:22 -0400 (EDT) Received: by iyb12 with SMTP id 12so5230110iyb.15 for ; Sun, 13 Mar 2011 06:00:04 -0700 (PDT) In-Reply-To: <201103111123.21063.arnd@arndb.de> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Arnd Bergmann Cc: linux-mmc@vger.kernel.org On Fri, Mar 11, 2011 at 4:23 AM, Arnd Bergmann wrote: > On Friday 11 March 2011, Andrei Warkentin wrote: >> > I also don't know what the effect of setting physical_block_size >> > and/or io_min is, possibly it no longer works if they are larger >> > than the MMU page size. Need to try this. >> >> The other thing is figuring out the default size limit for when the >> page align should be performed. I suppose it's safe enough to >> set it to 1.5 size the super_page_size. But that number came from the >> Toshiba card tests. Or it could be unbounded by default. I'd rather do >> the later. > > You mean always splitting (multiples of) full super-pages from partial > super-pages when the quirk flag is enabled? > > I think it depends on the performance numbers. Do you have any > meaningful measurements without the quirk, with the current implementation > and with the unbounded case? > > If the latter two are not much different on the toshiba card, that > would be a simpler implementation, and more likely to be useful on > other cards. > Revalidating the data now, along with some more tests, to get a better picture. It seems the more data I get, the less it makes sense :(. > I think we should also do measurements to see if the same quirk > actually has any negative effects on other cards, or if there > are even cases where it helps. Going to test on Sandisk eMMC as well. Thanks, A