Date: Tue, 21 Jul 2015 15:47:11 -0700 (PDT)
From: David Rientjes <rientjes@google.com>
To: Vlastimil Babka <vbabka@suse.cz>
cc: Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        "minkyung88.kim" <minkyung88.kim@lge.com>, kmk3210@gmail.com,
        Seungho Park <seungho1.park@lge.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>, Minchan Kim <minchan@kernel.org>,
        Michal Nazarewicz <mina86@mina86.com>,
        Laura Abbott <lauraa@codeaurora.org>,
        Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Mel Gorman <mgorman@suse.de>, Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [PATCH 2/2] mm: rename and move get/set_freepage_migratetype
In-Reply-To: <1437483218-18703-2-git-send-email-vbabka@suse.cz>
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References: <55969822.9060907@suse.cz> <1437483218-18703-1-git-send-email-vbabka@suse.cz> <1437483218-18703-2-git-send-email-vbabka@suse.cz>
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On Tue, 21 Jul 2015, Vlastimil Babka wrote:

> The pair of get/set_freepage_migratetype() functions are used to cache
> pageblock migratetype for a page put on a pcplist, so that it does not have
> to be retrieved again when the page is put on a free list (e.g. when pcplists
> become full). Historically it was also assumed that the value is accurate for
> pages on freelists (as the functions' names unfortunately suggest), but that
> cannot be guaranteed without affecting various allocator fast paths. It is in
> fact not needed and all such uses have been removed.
> 
> The last remaining (but pointless) usage related to pages of freelists is in
> move_freepages(), which this patch removes.
> 
> To prevent further confusion, rename the functions to
> get/set_pcppage_migratetype() and expand their description. Since all the
> users are now in mm/page_alloc.c, move the functions there from the shared
> header.
> 
> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
> Cc: Minchan Kim <minchan@kernel.org>
> Cc: Michal Nazarewicz <mina86@mina86.com>
> Cc: Laura Abbott <lauraa@codeaurora.org>
> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Mel Gorman <mgorman@suse.de>
> Cc: Johannes Weiner <hannes@cmpxchg.org>

Acked-by: David Rientjes <rientjes@google.com>
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