From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f68.google.com ([209.85.214.68]:52381 "EHLO mail-it0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030697AbeEXQxk (ORCPT ); Thu, 24 May 2018 12:53:40 -0400 Received: by mail-it0-f68.google.com with SMTP id y189-v6so3257326itb.2 for ; Thu, 24 May 2018 09:53:40 -0700 (PDT) Subject: Re: [PATCH V4] blk-mq: avoid to starve tag allocation after allocation process migrates To: Omar Sandoval , Ming Lei Cc: linux-block@vger.kernel.org, stable@vger.kernel.org, Omar Sandoval References: <20180524074910.32020-1-ming.lei@redhat.com> <20180524165216.GG12533@vader> From: Jens Axboe Message-ID: <8aaf8f1d-9b5b-0b4c-d374-efbdf2c125ba@kernel.dk> Date: Thu, 24 May 2018 10:53:37 -0600 MIME-Version: 1.0 In-Reply-To: <20180524165216.GG12533@vader> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: On 5/24/18 10:52 AM, Omar Sandoval wrote: > On Thu, May 24, 2018 at 03:49:10PM +0800, Ming Lei wrote: >> When the allocation process is scheduled back and the mapped hw queue is >> changed, fake one extra wake up on previous queue for compensating wake up >> miss, so other allocations on the previous queue won't be starved. >> >> This patch fixes one request allocation hang issue, which can be >> triggered easily in case of very low nr_request. >> >> Cc: >> Cc: Omar Sandoval > > Reviewed-by: Omar Sandoval > > The longer explanation you gave would be nice to have in the commit > message, but maybe Jens can add that when he applies it. Exactly, I had planned on augmenting the commit message since I don't think the above really explains it. I'll do that and get it applied. -- Jens Axboe