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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,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 86861C433E3 for ; Mon, 24 Aug 2020 19:18:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 33DDA20897 for ; Mon, 24 Aug 2020 19:18:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="NedftIdr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 33DDA20897 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 872736B002F; Mon, 24 Aug 2020 15:18:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 822CC6B0071; Mon, 24 Aug 2020 15:18:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6E97A6B0072; Mon, 24 Aug 2020 15:18:44 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0090.hostedemail.com [216.40.44.90]) by kanga.kvack.org (Postfix) with ESMTP id 5845E6B002F for ; Mon, 24 Aug 2020 15:18:44 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 8E1E1362B for ; Mon, 24 Aug 2020 19:18:43 +0000 (UTC) X-FDA: 77186424126.10.space48_160f81427055 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin10.hostedemail.com (Postfix) with ESMTP id 5B46516A4A5 for ; Mon, 24 Aug 2020 19:18:42 +0000 (UTC) X-HE-Tag: space48_160f81427055 X-Filterd-Recvd-Size: 2296 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf14.hostedemail.com (Postfix) with ESMTP for ; Mon, 24 Aug 2020 19:18:41 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 02AC120578; Mon, 24 Aug 2020 19:18:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598296721; bh=ruAaLHXCUgvFAIHtl74jpOBw0Y8uv95WYxQPoUYU1cY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=NedftIdrJSSiWqFW1zJ5dFmP61Pu/QmDrouLYmttdGPY33KM++6Saxqxq+SmyfGfN Qh64t3Q9lqnThGaAwsG1e0Jkjk86fDm6q0F0h4UOyEcyWd0zGGFzg9U9foXOGdeXjP DJURi9DXi/CdIz1nILadUy+sbGVFU+bu6aoUF0Fo= Date: Mon, 24 Aug 2020 12:18:40 -0700 From: Andrew Morton To: Miaohe Lin Cc: , Subject: Re: [PATCH] mm/mempool: Add 'else' to split mutually exclusive case Message-Id: <20200824121840.4cd7eb3dce03e8e1473221b3@linux-foundation.org> In-Reply-To: <20200824115354.7879-1-linmiaohe@huawei.com> References: <20200824115354.7879-1-linmiaohe@huawei.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 5B46516A4A5 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, 24 Aug 2020 07:53:54 -0400 Miaohe Lin wrote: > Add else to split mutually exclusive case and avoid some unnecessary check. > > --- a/mm/mempool.c > +++ b/mm/mempool.c > @@ -60,9 +60,8 @@ static void check_element(mempool_t *pool, void *element) > /* Mempools backed by slab allocator */ > if (pool->free == mempool_free_slab || pool->free == mempool_kfree) > __check_element(pool, element, ksize(element)); > - > /* Mempools backed by page allocator */ > - if (pool->free == mempool_free_pages) { > + else if (pool->free == mempool_free_pages) { > int order = (int)(long)pool->pool_data; > void *addr = kmap_atomic((struct page *)element); > It doesn't seem to change code generation (compiler is smart), but I think it helps readability.