From mboxrd@z Thu Jan 1 00:00:00 1970 From: Praveen G K Subject: Re: slow eMMC write speed Date: Wed, 28 Sep 2011 12:06:01 -0700 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:59720 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752227Ab1I1TGE convert rfc822-to-8bit (ORCPT ); Wed, 28 Sep 2011 15:06:04 -0400 Received: by fxe4 with SMTP id 4so876711fxe.19 for ; Wed, 28 Sep 2011 12:06:02 -0700 (PDT) In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Linus Walleij Cc: linux-mmc@vger.kernel.org On Tue, Sep 27, 2011 at 10:42 PM, Linus Walleij wrote: > On Fri, Sep 23, 2011 at 7:05 AM, Praveen G K w= rote: > >> I am working on the block driver module of the eMMC driver (SDIO 3.0 >> controller). =A0I am seeing very low write speed for eMMC transfers.= =A0On >> further debugging, I observed that every 63rd and 64th transfer take= s >> a long time. > > Are you not just seeing the card-internal garbage collection? > http://lwn.net/Articles/428584/ Does this mean, theoretically, I should be able to achieve larger speeds if I am not using linux? So, is this a software issue? or if there is a way to increase the size of bounce buffers to 4MB? > Yours, > Linus Walleij >