From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DB45C41604 for ; Tue, 6 Oct 2020 07:41:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD6FE20789 for ; Tue, 6 Oct 2020 07:41:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SnA6ci52" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726991AbgJFHlU (ORCPT ); Tue, 6 Oct 2020 03:41:20 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:49480 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726670AbgJFHlU (ORCPT ); Tue, 6 Oct 2020 03:41:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601970079; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=eFC0ISn2+rWqsHgSwE4sZ0+UQ3DhHxUZGAadpsJBkLw=; b=SnA6ci52OjArJTJSaAYCMYdXCqHtfbII7sEGje6ijOxmHEXl9GDSnOpEEbM1vR9B4E9+SV Iz1xWnvs10YKOTqB6E5GS6ria/6iLRrpTEnyeqQi/4KlDCvxnk4JnMHpw2hj9coboAbYdQ p/bfj68fCfXELer50PplT41HRIxJjbw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-65-JKwoqOqxNom9jlTPhAa4hQ-1; Tue, 06 Oct 2020 03:41:15 -0400 X-MC-Unique: JKwoqOqxNom9jlTPhAa4hQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EC3AE1868411; Tue, 6 Oct 2020 07:41:13 +0000 (UTC) Received: from T590 (ovpn-12-63.pek2.redhat.com [10.72.12.63]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C4C5755767; Tue, 6 Oct 2020 07:41:04 +0000 (UTC) Date: Tue, 6 Oct 2020 15:41:00 +0800 From: Ming Lei To: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Cc: Veronika Kabatova , Sagi Grimberg , Tejun Heo , Christoph Hellwig , Jens Axboe , Bart Van Assche Subject: Re: [PATCH V7 0/2] percpu_ref & block: reduce memory footprint of percpu_ref in fast path Message-ID: <20201006074100.GA26059@T590> References: <20201001154842.26896-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201001154842.26896-1-ming.lei@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 01, 2020 at 11:48:40PM +0800, Ming Lei wrote: > Hi, > > The 1st patch removes memory footprint of percpu_ref in fast path > from 7 words to 2 words, since it is often used in fast path and > embedded in user struct. > > The 2nd patch moves .q_usage_counter to 1st cacheline of > 'request_queue'. > > Simple test on null_blk shows ~2% IOPS boost on one 16cores(two threads > per core) machine, dual socket/numa. > > V7: > - add comments about reason for struct split Hello Jens Can you consider to merge the patchset in block tree if you are fine? Thanks, Ming