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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 59CE0C433E7 for ; Tue, 13 Oct 2020 23:57:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 236B722246 for ; Tue, 13 Oct 2020 23:57:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602633420; bh=WGnmi9mAf2C/DobI1Es+t829I+zCkkB1mrr4P42tt6I=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=MUmAg1KxYBDdok94K3BLOgfHsFLV34LWwg2kgmGXg5BgJbOH2UfXh/OzOlhL7B+ht Mfbd5iM3ayZsun35R1KZaeKu/S+iezPpuiqdGl8zfY9D6h3tAFU4UsWDVzawzKTs8H GRJ3rnb593uozrLE7SndDxemcwRSikbKYLNwCjx0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388695AbgJMX47 (ORCPT ); Tue, 13 Oct 2020 19:56:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:42744 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387742AbgJMX47 (ORCPT ); Tue, 13 Oct 2020 19:56:59 -0400 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 DE9652223F; Tue, 13 Oct 2020 23:56:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602633419; bh=WGnmi9mAf2C/DobI1Es+t829I+zCkkB1mrr4P42tt6I=; h=Date:From:To:Subject:In-Reply-To:From; b=0MYb0i0+l4eGoC0Gd7m7JhJ+NDX68DYzjTEPQtVSFZPkPl9XXb5j3isQUWgpkw4Yh O5FcKDqQqetAS7zfc5V1ckI0Ao5R5uCWvaO19E9sDzAfWPV8UW/4dOmrrrh8M601AE QvgKtOslEJIfo60hm35XMEaX3gEn5JtQv/XMKhrM= Date: Tue, 13 Oct 2020 16:56:58 -0700 From: Andrew Morton To: akpm@linux-foundation.org, iamjoonsoo.kim@lge.com, linux-mm@kvack.org, mateusznosek0@gmail.com, mgorman@suse.de, mm-commits@vger.kernel.org, rientjes@google.com, torvalds@linux-foundation.org, vbabka@suse.cz Subject: [patch 156/181] mm/compaction.c: micro-optimization remove unnecessary branch Message-ID: <20201013235658.mJxIcj5ip%akpm@linux-foundation.org> In-Reply-To: <20201013164658.3bfd96cc224d8923e66a9f4e@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Mateusz Nosek Subject: mm/compaction.c: micro-optimization remove unnecessary branch The same code can work both for 'zone->compact_considered > defer_limit' and 'zone->compact_considered >= defer_limit'. In the latter there is one branch less which is more effective considering performance. Link: https://lkml.kernel.org/r/20200913190448.28649-1-mateusznosek0@gmail.com Signed-off-by: Mateusz Nosek Reviewed-by: Andrew Morton Cc: Joonsoo Kim Cc: Vlastimil Babka Cc: Mel Gorman Cc: David Rientjes Signed-off-by: Andrew Morton --- mm/compaction.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/mm/compaction.c~mm-compactionc-micro-optimization-remove-unnecessary-branch +++ a/mm/compaction.c @@ -180,11 +180,10 @@ bool compaction_deferred(struct zone *zo return false; /* Avoid possible overflow */ - if (++zone->compact_considered > defer_limit) + if (++zone->compact_considered >= defer_limit) { zone->compact_considered = defer_limit; - - if (zone->compact_considered >= defer_limit) return false; + } trace_mm_compaction_deferred(zone, order); _