From mboxrd@z Thu Jan 1 00:00:00 1970 From: Per Forlin Subject: Re: [PATCH] mmc: mxs-mmc: add support for pre_req and post_req Date: Thu, 21 Apr 2011 11:47:19 +0200 Message-ID: References: <1302116833-24540-1-git-send-email-per.forlin@linaro.org> <1303058010-30256-1-git-send-email-shawn.guo@linaro.org> <20110417164830.GE17935@S2100-06.ap.freescale.net> <20110420140120.GF1965@S2100-06.ap.freescale.net> <20110421062924.GB4024@S2100-06.ap.freescale.net> <20110421091115.GH4024@S2100-06.ap.freescale.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-qw0-f46.google.com ([209.85.216.46]:57303 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750707Ab1DUJrU convert rfc822-to-8bit (ORCPT ); Thu, 21 Apr 2011 05:47:20 -0400 Received: by qwk3 with SMTP id 3so764597qwk.19 for ; Thu, 21 Apr 2011 02:47:19 -0700 (PDT) In-Reply-To: <20110421091115.GH4024@S2100-06.ap.freescale.net> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Shawn Guo Cc: Shawn Guo , linaro-kernel@lists.linaro.org, linux-mmc@vger.kernel.org, cjb@laptop.org, linux-arm-kernel@lists.infradead.org, patches@linaro.org On 21 April 2011 11:11, Shawn Guo wrote: > On Thu, Apr 21, 2011 at 10:46:18AM +0200, Per Forlin wrote: >> On 21 April 2011 08:29, Shawn Guo wrote: >> > On Wed, Apr 20, 2011 at 05:30:22PM +0200, Per Forlin wrote: >> > [...] >> >> Remove dma_map and dma_unmap from your host driver and run the te= sts >> >> (obviously nonblocking and blocking will have the same results). = If >> >> there is still no performance gain the cache penalty is very smal= l on >> >> your platform and therefore nonblocking doesn't improve things mu= ch. >> >> Please let me know the result. >> >> >> > Sorry, I could not understand. =A0What's the point to run the test= when >> > the driver is even broken. =A0The removal of =A0dma_map_sg and >> > dma_unmap_sg makes mxs-mmc host driver broken. >> The point is only to get a measurement of the cost of handling >> dma_map_sg and dma_unmap_sg, this is the maximum time mmc nonblockin= g >> can save. >> The nonblocking mmc_test should save the total time of dma_map_sg an= d >> dma_unmap_sg, if the pre_req and post_req hooks are implemented >> correctly. >> Running without dma_map_sg and dma_unmap_sg will confirm if the >> pre_req and post_req hooks are implemented correctly. >> > With dma_map_sg and dma_unmap_sg removed, the mmc_test gave very low > numbers, though blocking and non-blocking numbers are same. =A0Is it > an indication that pre_req and post_req hooks are not implemented > correctly? I think you could get the same numbers for the nonblocking with dma_map and dma_unmap in place. > =A0If yes, can you please help to catch the mistakes? I will take a look. > -- > Regards, > Shawn > > Regards, Per