Return-Path: Received: from mail-wi0-f181.google.com ([209.85.212.181]:35980 "EHLO mail-wi0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754306AbbJGOjW (ORCPT ); Wed, 7 Oct 2015 10:39:22 -0400 Received: by wicgb1 with SMTP id gb1so214580106wic.1 for ; Wed, 07 Oct 2015 07:39:21 -0700 (PDT) Subject: Re: [PATCH v2 06/16] xprtrdma: Use workqueue to process RPC/RDMA replies To: Chuck Lever , linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org References: <20151006142430.11788.42604.stgit@manet.1015granger.net> <20151006145924.11788.64757.stgit@manet.1015granger.net> From: Sagi Grimberg Message-ID: <56152E96.9040400@dev.mellanox.co.il> Date: Wed, 7 Oct 2015 17:39:18 +0300 MIME-Version: 1.0 In-Reply-To: <20151006145924.11788.64757.stgit@manet.1015granger.net> Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-nfs-owner@vger.kernel.org List-ID: On 10/6/2015 5:59 PM, Chuck Lever wrote: > The reply tasklet is fast, but it's single threaded. After reply > traffic saturates a single CPU, there's no more reply processing > capacity. > > Replace the tasklet with a workqueue to spread reply handling across > all CPUs. This also moves RPC/RDMA reply handling out of the soft > IRQ context and into a context that allows sleeps. Hi Chuck, I'm probably missing something here, but do you ever schedule in the workqueue context? Don't you need to explicitly schedule after a jiffie or so the code works also in a non fully preemptable kernel?