From mboxrd@z Thu Jan 1 00:00:00 1970 From: Seungwon Jeon Subject: RE: [PATCH] mmc: dw_mmc: Support predefined multiple block transfers. Date: Wed, 28 Sep 2011 17:23:47 +0900 Message-ID: <003101cc7db7$f203e350$d60ba9f0$%jun@samsung.com> References: <001901cc7c42$00147c10$003d7430$%jun@samsung.com> <992253991.685205.1317054932934.JavaMail.root@zimbra-prod-mbox-2.vmware.com> <001f01cc7cba$f1238560$d36a9020$%jun@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-reply-to: Content-language: ko Sender: linux-samsung-soc-owner@vger.kernel.org To: "'Andrei E. Warkentin'" Cc: 'Andrei Warkentin' , 'Chris Ball' , linux-samsung-soc@vger.kernel.org, 'kgene kim' , 'dh han' , linux-mmc@vger.kernel.org List-Id: linux-mmc@vger.kernel.org Andrei Warkentin wrote: > 2011/9/26 Seungwon Jeon : > > Andrei Warkentin wrote: > >> Hi Seungwon, > >> > >> ----- Original Message ----- > >> > From: "Seungwon Jeon" > >> > To: linux-mmc@vger.kernel.org > >> > Cc: "Chris Ball" , linux-samsung-soc@vger.kernel.org, > >> "kgene kim" , "dh han" > >> > , "Seungwon Jeon" > >> > Sent: Monday, September 26, 2011 7:46:59 AM > >> > Subject: [PATCH] mmc: dw_mmc: Support predefined multiple block > >> transfers. > >> > > >> > This patch adds the support for predefined multiple block read/write. > >> > > >> > Signed-off-by: Seungwon Jeon > >> > >> Without knowing much about dw_mmc host, your logic otherwise looks ok, > >> given what > >> I've previously done for SDHCI as far as CMD23/Auto-CMD23 enhancement. > >> Just curious, what eMMC cards did you test this on, and what > improvement > >> did you see? > > > > Thank you for review. > > As you done, predefined transfer is required for reliable writes and > eMMC4.5 feature. > > Sadly, I didn't gain an improvement in my case. > > (I don't know whether I can clarify the tested eMMC card, just one > sample.) > > > > So far I've seen some Sandisk cards have a noticeable real-life > improvement (30%) over > open-ended transfers. > > You might wish to try out https://github.com/andreiw/superalign to be > certain. I had already tested this patch with IOZONE, but I found no difference. Maybe a result depends on eMMC device. As your recommend, I applied above benchmark tool. Predefined transfer seems like a little better, but there is no difference. Thanks. Seungwon Jeon. > > A > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html