From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH] omap_hsmmc: Reduce max_segs Date: Tue, 20 Jun 2017 23:24:27 -0700 Message-ID: <20170621062427.GP3730@atomide.com> References: <20170619093644.16054-1-willn@resin.io> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from muru.com ([72.249.23.125]:59286 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750753AbdFUGYc (ORCPT ); Wed, 21 Jun 2017 02:24:32 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Will Newton Cc: linux-omap@vger.kernel.org, "linux-mmc@vger.kernel.org" , Kishon Vijay Abraham I , Ravikumar Kattekola , Peter Ujfalusi * Will Newton [170620 05:39]: > Just adding a few people to CC. I'd love to get some feedback as to > whether this patch makes sense or not. > > On Mon, Jun 19, 2017 at 10:36 AM, Will Newton wrote: > > Reduce max_segs to a value that allows allocation of an entire > > descriptor list within a single page. This avoids doing a > > higher order GFP_ATOMIC allocation when setting up a transfer > > which can potentially fail and lead to I/O failures. I recall we only ever have few SG entries so if there is no performance impact I see no reason to lower it to save memory. Care to check if that's the case still? Regards, Tony > > Signed-off-by: Will Newton > > --- > > drivers/mmc/host/omap_hsmmc.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c > > index 1438a72..d5f42d9 100644 > > --- a/drivers/mmc/host/omap_hsmmc.c > > +++ b/drivers/mmc/host/omap_hsmmc.c > > @@ -2864,9 +2864,9 @@ static int omap_hsmmc_probe(struct platform_device *pdev) > > host->use_adma = true; > > } > > > > - /* Since we do only SG emulation, we can have as many segs > > - * as we want. */ > > - mmc->max_segs = 1024; > > + /* Set this to a value that allows allocating an entire descriptor > > + list within a page (zero order allocation). */ > > + mmc->max_segs = 64; > > > > mmc->max_blk_size = 512; /* Block Length at max can be 1024 */ > > mmc->max_blk_count = 0xFFFF; /* No. of Blocks is 16 bits */ > > -- > > 2.7.4 > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html