From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f198.google.com (mail-pl1-f198.google.com [209.85.214.198]) by kanga.kvack.org (Postfix) with ESMTP id D846F6B000C for ; Fri, 5 Oct 2018 04:10:24 -0400 (EDT) Received: by mail-pl1-f198.google.com with SMTP id f59-v6so7295935plb.5 for ; Fri, 05 Oct 2018 01:10:24 -0700 (PDT) Received: from alexa-out-blr-01.qualcomm.com (alexa-out-blr-01.qualcomm.com. [103.229.18.197]) by mx.google.com with ESMTPS id n24-v6si7546760pff.136.2018.10.05.01.10.23 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 05 Oct 2018 01:10:23 -0700 (PDT) From: Arun KS Subject: [PATCH v5 2/2] mm/page_alloc: remove software prefetching in __free_pages_core Date: Fri, 5 Oct 2018 13:40:06 +0530 Message-Id: <1538727006-5727-2-git-send-email-arunks@codeaurora.org> In-Reply-To: <1538727006-5727-1-git-send-email-arunks@codeaurora.org> References: <1538727006-5727-1-git-send-email-arunks@codeaurora.org> Sender: owner-linux-mm@kvack.org List-ID: To: kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, boris.ostrovsky@oracle.com, jgross@suse.com, akpm@linux-foundation.org, dan.j.williams@intel.com, mhocko@suse.com, vbabka@suse.cz, iamjoonsoo.kim@lge.com, gregkh@linuxfoundation.org, osalvador@suse.de, malat@debian.org, kirill.shutemov@linux.intel.com, jrdr.linux@gmail.com, yasu.isimatu@gmail.com, mgorman@techsingularity.net, aaron.lu@intel.com, devel@linuxdriverproject.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, xen-devel@lists.xenproject.org Cc: vatsa@codeaurora.org, vinmenon@codeaurora.org, getarunks@gmail.com, Arun KS 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 7ab5274..90db431 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1258,14 +1258,10 @@ 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