From patchwork Sat Mar 11 05:17:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 13170633 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B9BDC61DA4 for ; Sat, 11 Mar 2023 05:17:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230032AbjCKFRp (ORCPT ); Sat, 11 Mar 2023 00:17:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46746 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229910AbjCKFRc (ORCPT ); Sat, 11 Mar 2023 00:17:32 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78563140515; Fri, 10 Mar 2023 21:17:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=O4b3Qxh/i39uh+zwcsp8AsaOxA5M41InYNm+nORqDPs=; b=3Ow6eDvBTwIXsDf145Zz2dBLVB yuBPoQbmbDY0TruIbFFrwghKp2pc0QFVg5Lm3yW9FgiDn5BzW4MiwSmotkIXMBPGPXebmLnuLQfxE 62RMq0qzsEX+dOSlhoOuwYd8Bbwmq6vO7DuS1Dv9RM4oKsz03tnLCwCxBU/hwSf0YhPHS5TQyNae0 +KqHD4ebj04pdEw4z40rApf4pnL5D2rC+G/Yb4ddAN0AACFeRBYoHeXVYYKvNdbc+paOa5z5Ymlw7 Hv871ZP8Gojpg8tRM5KsGW8Zcv7Z7JHAHpEWEIOX8mGKb8hXlKlk8AeDIJjk0ql6FnsB6BixcMqfc /DUlEzCQ==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1parbj-00HBNE-HP; Sat, 11 Mar 2023 05:17:27 +0000 From: Luis Chamberlain To: linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org, pmladek@suse.com, david@redhat.com, petr.pavlu@suse.com, prarit@redhat.com Cc: christophe.leroy@csgroup.eu, song@kernel.org, mcgrof@kernel.org, torvalds@linux-foundation.org Subject: [RFC 11/12] module: use list_add_tail_rcu() when adding module Date: Fri, 10 Mar 2023 21:17:11 -0800 Message-Id: <20230311051712.4095040-12-mcgrof@kernel.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20230311051712.4095040-1-mcgrof@kernel.org> References: <20230311051712.4095040-1-mcgrof@kernel.org> MIME-Version: 1.0 Sender: Luis Chamberlain Precedence: bulk List-ID: Put a new module at the end of the list intead of making new modules at the top of the list. find_module_all() start the hunt using the first entry on the list, if we assume that the modules which are first loaded are the most frequently looked for modules this should provide a tiny optimization. This is theoretical, and could use more actual data by analzying the impact of this patch on boot time a slew of systems using systemd-analyze. Signed-off-by: Luis R. Rodriguez --- kernel/module/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/module/main.c b/kernel/module/main.c index 909454f9616e..bc9202b60d55 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -2608,7 +2608,7 @@ static int add_unformed_module(struct module *mod) goto out; mod_update_bounds(mod); - list_add_rcu(&mod->list, &modules); + list_add_tail_rcu(&mod->list, &modules); mod_tree_insert(mod); err = 0;