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=-5.8 required=3.0 tests=BAYES_00,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 A9D4BC4338F for ; Thu, 12 Aug 2021 06:55:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8AC616101E for ; Thu, 12 Aug 2021 06:55:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232459AbhHLGz3 (ORCPT ); Thu, 12 Aug 2021 02:55:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56104 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230323AbhHLGz3 (ORCPT ); Thu, 12 Aug 2021 02:55:29 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A006CC061765; Wed, 11 Aug 2021 23:55:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=6LfU+GqQO+88RtfboxgAba8JBTOeXEYqxWLd6CIebTo=; b=fwAHdYwqNWolCxAtsymlWfUwzu RX326i8/F4uelq4wtoXF/JhUnJv/74ZQpCEewebukfZMcFqDJDYOuMKk1BBPjL1/BlKLhTIBU/sGl A2ZwgiBlDUMqniTS6qnJwQhJr3rBYUfo6QoLakpEA19T5odTpVbJ8yOWsawTZ1igxGEWovLRvqI0f 8fhB+xpjv4h4DINcndLjI+2BkpVrZ1PX7dFrgvvBRqQ/HtV2YUh2XQfIeubLcyoLoMQkWeXhjNPql b7eFw6/gvGqIyJkIxzg7AFx/nsR88slo9pqWSXJ+UiLB849qAn0a8zY9wWKN9/cpJLgrl8v7ihQCW f+SzEj8A==; Received: from [2001:4bb8:184:6215:d7d:1904:40de:694d] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mE4ZJ-00EG01-6I; Thu, 12 Aug 2021 06:52:39 +0000 Date: Thu, 12 Aug 2021 08:51:56 +0200 From: Christoph Hellwig To: Jens Axboe Cc: io-uring@vger.kernel.org, linux-block@vger.kernel.org, hch@infradead.org Subject: Re: [PATCH 1/6] bio: optimize initialization of a bio Message-ID: References: <20210811193533.766613-1-axboe@kernel.dk> <20210811193533.766613-2-axboe@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210811193533.766613-2-axboe@kernel.dk> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Wed, Aug 11, 2021 at 01:35:28PM -0600, Jens Axboe wrote: > The memset() used is measurably slower in targeted benchmarks. Get rid > of it and fill in the bio manually, in a separate helper. If you have some numbers if would be great to throw them in here. > +static inline void __bio_init(struct bio *bio) Why is this split from bio_init and what are the criteria where an initialization goes? > + bio->bi_flags = bio->bi_ioprio = bio->bi_write_hint = 0; Please keep each initialization on a separate line.