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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 66401C32789 for ; Tue, 6 Nov 2018 06:03:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 36E002081D for ; Tue, 6 Nov 2018 06:03:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 36E002081D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730112AbeKFP1K (ORCPT ); Tue, 6 Nov 2018 10:27:10 -0500 Received: from alexa-out-blr-02.qualcomm.com ([103.229.18.198]:41667 "EHLO alexa-out-blr.qualcomm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729337AbeKFP1J (ORCPT ); Tue, 6 Nov 2018 10:27:09 -0500 X-IronPort-AV: E=Sophos;i="5.54,470,1534789800"; d="scan'208";a="231191" Received: from ironmsg01-blr.qualcomm.com ([10.86.208.130]) by alexa-out-blr.qualcomm.com with ESMTP/TLS/AES256-SHA; 06 Nov 2018 11:33:34 +0530 X-IronPort-AV: E=McAfee;i="5900,7806,9068"; a="5671283" Received: from blr-ubuntu-104.ap.qualcomm.com (HELO blr-ubuntu-104.qualcomm.com) ([10.79.40.64]) by ironmsg01-blr.qualcomm.com with ESMTP; 06 Nov 2018 11:33:33 +0530 Received: by blr-ubuntu-104.qualcomm.com (Postfix, from userid 346745) id 67FC831C6; Tue, 6 Nov 2018 11:33:33 +0530 (IST) From: Arun KS To: arunks.linux@gmail.com, akpm@linux-foundation.org, mhocko@kernel.org, vbabka@suse.cz, osalvador@suse.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: getarunks@gmail.com, Arun KS Subject: [PATCH v6 2/2] mm/page_alloc: remove software prefetching in __free_pages_core Date: Tue, 6 Nov 2018 11:33:14 +0530 Message-Id: <1541484194-1493-2-git-send-email-arunks@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1541484194-1493-1-git-send-email-arunks@codeaurora.org> References: <1541484194-1493-1-git-send-email-arunks@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org They not only increase the code footprint, they actually make things slower rather than faster. Remove them as contemporary hardware doesn't need any hint. Suggested-by: Dan Williams Signed-off-by: Arun KS --- mm/page_alloc.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 7cf503f..a1b9a6a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1270,14 +1270,10 @@ void __free_pages_core(struct page *page, unsigned int order) struct page *p = page; unsigned int loop; - prefetchw(p); - for (loop = 0; loop < (nr_pages - 1); loop++, p++) { - prefetchw(p + 1); + for (loop = 0; loop < nr_pages ; loop++, p++) { __ClearPageReserved(p); set_page_count(p, 0); } - __ClearPageReserved(p); - set_page_count(p, 0); page_zone(page)->managed_pages += nr_pages; set_page_refcounted(page); -- 1.9.1