From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752471AbcDZNax (ORCPT ); Tue, 26 Apr 2016 09:30:53 -0400 Received: from mx2.suse.de ([195.135.220.15]:41383 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752436AbcDZNav (ORCPT ); Tue, 26 Apr 2016 09:30:51 -0400 Subject: Re: [PATCH 14/28] mm, page_alloc: Simplify last cpupid reset To: Mel Gorman , Andrew Morton References: <1460710760-32601-1-git-send-email-mgorman@techsingularity.net> <1460711275-1130-1-git-send-email-mgorman@techsingularity.net> <1460711275-1130-2-git-send-email-mgorman@techsingularity.net> Cc: Jesper Dangaard Brouer , Linux-MM , LKML From: Vlastimil Babka Message-ID: <571F6D89.1000704@suse.cz> Date: Tue, 26 Apr 2016 15:30:49 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.1 MIME-Version: 1.0 In-Reply-To: <1460711275-1130-2-git-send-email-mgorman@techsingularity.net> Content-Type: text/plain; charset=iso-8859-2; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/15/2016 11:07 AM, Mel Gorman wrote: > The current reset unnecessarily clears flags and makes pointless calculations. Ugh, indeed. > Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka > --- > include/linux/mm.h | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index ffcff53e3b2b..60656db00abd 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -837,10 +837,7 @@ extern int page_cpupid_xchg_last(struct page *page, int cpupid); > > static inline void page_cpupid_reset_last(struct page *page) > { > - int cpupid = (1 << LAST_CPUPID_SHIFT) - 1; > - > - page->flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT); > - page->flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT; > + page->flags |= LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT; > } > #endif /* LAST_CPUPID_NOT_IN_PAGE_FLAGS */ > #else /* !CONFIG_NUMA_BALANCING */ > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f72.google.com (mail-wm0-f72.google.com [74.125.82.72]) by kanga.kvack.org (Postfix) with ESMTP id 50E806B0270 for ; Tue, 26 Apr 2016 09:30:52 -0400 (EDT) Received: by mail-wm0-f72.google.com with SMTP id r12so12446132wme.0 for ; Tue, 26 Apr 2016 06:30:52 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id hc5si29990405wjb.226.2016.04.26.06.30.50 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 26 Apr 2016 06:30:50 -0700 (PDT) Subject: Re: [PATCH 14/28] mm, page_alloc: Simplify last cpupid reset References: <1460710760-32601-1-git-send-email-mgorman@techsingularity.net> <1460711275-1130-1-git-send-email-mgorman@techsingularity.net> <1460711275-1130-2-git-send-email-mgorman@techsingularity.net> From: Vlastimil Babka Message-ID: <571F6D89.1000704@suse.cz> Date: Tue, 26 Apr 2016 15:30:49 +0200 MIME-Version: 1.0 In-Reply-To: <1460711275-1130-2-git-send-email-mgorman@techsingularity.net> Content-Type: text/plain; charset=iso-8859-2; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman , Andrew Morton Cc: Jesper Dangaard Brouer , Linux-MM , LKML On 04/15/2016 11:07 AM, Mel Gorman wrote: > The current reset unnecessarily clears flags and makes pointless calculations. Ugh, indeed. > Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka > --- > include/linux/mm.h | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index ffcff53e3b2b..60656db00abd 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -837,10 +837,7 @@ extern int page_cpupid_xchg_last(struct page *page, int cpupid); > > static inline void page_cpupid_reset_last(struct page *page) > { > - int cpupid = (1 << LAST_CPUPID_SHIFT) - 1; > - > - page->flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT); > - page->flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT; > + page->flags |= LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT; > } > #endif /* LAST_CPUPID_NOT_IN_PAGE_FLAGS */ > #else /* !CONFIG_NUMA_BALANCING */ > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org