Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751672AbbKOMwE (ORCPT ); Sun, 15 Nov 2015 07:52:04 -0500 Received: from verein.lst.de ([213.95.11.211]:48494 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751336AbbKOMwC (ORCPT ); Sun, 15 Nov 2015 07:52:02 -0500 Date: Sun, 15 Nov 2015 13:51:59 +0100 From: Christoph Hellwig To: Sagi Grimberg Cc: Christoph Hellwig , Or Gerlitz , "linux-rdma@vger.kernel.org" , Bart Van Assche , axboe@fb.com, "linux-scsi@vger.kernel.org" , Linux Kernel Subject: Re: [PATCH 1/9] move blk_iopoll to limit and make it generally available Message-ID: <20151115125159.GA2218@lst.de> References: <1447422410-20891-1-git-send-email-hch@lst.de> <1447422410-20891-2-git-send-email-hch@lst.de> <20151114070200.GA27738@lst.de> <564846E9.9070301@dev.mellanox.co.il> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <564846E9.9070301@dev.mellanox.co.il> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1100 Lines: 23 On Sun, Nov 15, 2015 at 10:48:41AM +0200, Sagi Grimberg wrote: > I have attempted to convert iser to use blk_iopoll in the past, however > I've seen inconsistent performance and latency skews (comparing to > tasklets iser is using today). This was manifested in IOPs test cases > where I ran multiple threads with higher queue-depth and not in > sanitized pure latency (QD=1) test cases. Unfortunately I didn't have > the time to pick it up since. > > I do have every intention of testing it again with this. If it still > exist we will need to find the root-cause of it before converting > drivers to use it. Thanks. If you see issue like that with high iops and high loads the next thing to check are: a) increasing the budget (both in the main poll loop and the IB code) b) try without the single jiffie time limit in the main softirq handler -- 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/