Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965707Ab3FULuD (ORCPT ); Fri, 21 Jun 2013 07:50:03 -0400 Received: from nat28.tlf.novell.com ([130.57.49.28]:38976 "EHLO nat28.tlf.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965568Ab3FULuB (ORCPT ); Fri, 21 Jun 2013 07:50:01 -0400 Message-Id: <51C45A0602000078000DFA4C@nat28.tlf.novell.com> X-Mailer: Novell GroupWise Internet Agent 12.0.2 Date: Fri, 21 Jun 2013 12:49:58 +0100 From: "Jan Beulich" To: "Roger Pau Monne" Cc: , "Konrad Rzeszutek Wilk" , Subject: Re: [Xen-devel] [PATCH 4/4] xen-blkfront: increase the default number of indirect segments References: <1371812216-17093-1-git-send-email-roger.pau@citrix.com> <1371812216-17093-5-git-send-email-roger.pau@citrix.com> In-Reply-To: <1371812216-17093-5-git-send-email-roger.pau@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1939 Lines: 52 >>> On 21.06.13 at 12:56, Roger Pau Monne wrote: > When using certain storage devices (like RAID) having a bigger number > of segments per request provides better performance. And there's no drawback (higher memory foot print if nothing else) on "certain other storage devices"? Adjusting defaults just because it is beneficial for some devices, but may adversely affect others is not really a good thing - in such an event, you'd be better off determining the default dynamically per device. Jan > Signed-off-by: Roger Pau Monné > Reported-by: Steven Haigh > Cc: Konrad Rzeszutek Wilk > --- > drivers/block/xen-blkfront.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c > index 2e1ee34..4e3ab34 100644 > --- a/drivers/block/xen-blkfront.c > +++ b/drivers/block/xen-blkfront.c > @@ -94,9 +94,9 @@ static const struct block_device_operations xlvbd_block_fops; > * by the backend driver. > */ > > -static unsigned int xen_blkif_max_segments = 32; > +static unsigned int xen_blkif_max_segments = 64; > module_param_named(max, xen_blkif_max_segments, int, S_IRUGO); > -MODULE_PARM_DESC(max, "Maximum amount of segments in indirect requests > (default is 32)"); > +MODULE_PARM_DESC(max, "Maximum amount of segments in indirect requests > (default is 64)"); > > #define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE) > > -- > 1.7.7.5 (Apple Git-26) > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/