Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756783Ab3JOBHh (ORCPT ); Mon, 14 Oct 2013 21:07:37 -0400 Received: from mail-pd0-f172.google.com ([209.85.192.172]:44130 "EHLO mail-pd0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755780Ab3JOBHg (ORCPT ); Mon, 14 Oct 2013 21:07:36 -0400 Message-Id: <20131015010500.435964635@kernel.org> User-Agent: quilt/0.60-1 Date: Tue, 15 Oct 2013 09:05:00 +0800 From: Shaohua Li To: linux-kernel@vger.kernel.org, axboe@kernel.dk Cc: kmo@daterainc.com Subject: [patch 0/4 v2] blk-mq: use percpu_ida to manage tags Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 875 Lines: 21 Hi, blk-mq and percpu_ida use similar algorithm to manage tags. The difference is when a cpu can't allocate tags, blk-mq will use ipi to purge remote cpu cache, while percpu-ida directly purges remote cpu cache. In practice, the percpu-ida approach is much faster when we can't allocate enough for percpu cache. This patch makes blk-mq use percpu_ida to manage tags, this avoids some duplicate code and has better performance as I mentioned. To test the patches, rebase blk-mq tree to latest kernel first. The v2 patch updated some log descriptions, fixed one issue Kent pointed out and added performance data. Thanks, Shaohua -- 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/