From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f175.google.com (mail-ig0-f175.google.com [209.85.213.175]) by kanga.kvack.org (Postfix) with ESMTP id A95586B0038 for ; Mon, 23 Mar 2015 19:16:23 -0400 (EDT) Received: by igcau2 with SMTP id au2so41894646igc.1 for ; Mon, 23 Mar 2015 16:16:23 -0700 (PDT) Received: from mail-ie0-x22b.google.com (mail-ie0-x22b.google.com. [2607:f8b0:4001:c03::22b]) by mx.google.com with ESMTPS id il2si7273238igb.24.2015.03.23.16.16.23 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 23 Mar 2015 16:16:23 -0700 (PDT) Received: by ieclw3 with SMTP id lw3so48206558iec.2 for ; Mon, 23 Mar 2015 16:16:23 -0700 (PDT) Date: Mon, 23 Mar 2015 16:16:21 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH] mm/compaction: reset compaction scanner positions In-Reply-To: <1426939106-30347-1-git-send-email-gioh.kim@lge.com> Message-ID: References: <1426939106-30347-1-git-send-email-gioh.kim@lge.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Gioh Kim Cc: akpm@linux-foundation.org, vbabka@suse.cz, iamjoonsoo.kim@lge.com, mgorman@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, gunho.lee@lge.com On Sat, 21 Mar 2015, Gioh Kim wrote: > When the compaction is activated via /proc/sys/vm/compact_memory > it would better scan the whole zone. > And some platform, for instance ARM, has the start_pfn of a zone is zero. > Therefore the first try to compaction via /proc doesn't work. > It needs to force to reset compaction scanner position at first. > > Signed-off-by: Gioh Kim That shouldn't be a valid email address. > Acked-by: Vlastimil Babka Acked-by: David Rientjes I was thinking that maybe this would be better handled as part of the comapct_zone() logic, i.e. set cc->free_pfn and cc->migrate_pfn based on a helper function that understands cc->order == -1 should compact the entire zone. However, after scanning the entire zone as a result of this write, the existing cached pfns probably don't matter anymore. So this seems fine. -- 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