From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH v2 2/3] blk-mq: add tag allocation policy Date: Mon, 22 Dec 2014 16:25:19 -0700 Message-ID: <5498A85F.7090508@fb.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:22943 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754020AbaLVXZr (ORCPT ); Mon, 22 Dec 2014 18:25:47 -0500 In-Reply-To: Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Shaohua Li , linux-ide@vger.kernel.org Cc: Kernel-team@fb.com, Tejun Heo , Christoph Hellwig On 12/18/2014 11:46 AM, Shaohua Li wrote: > This is the blk-mq part to support tag allocation policy. The default > allocation policy isn't changed (though it's not a strict FIFO). The new > policy is round-robin for libata. But it's a try-best implementation. If > multiple tasks are competing, the tags returned will be mixed (which is > unavoidable even with !mq, as requests from different tasks can be > mixed in queue) Can we get rid of the atomic_read() on non-rr? It's never set outside of initialization there. -- Jens Axboe