Message-ID: <4FE549E8.2050905@jp.fujitsu.com>
Date: Sat, 23 Jun 2012 13:45:28 +0900
From: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
User-Agent: Mozilla/5.0 (Windows NT 6.0; rv:13.0) Gecko/20120614 Thunderbird/13.0.1
MIME-Version: 1.0
To: Minchan Kim <minchan@kernel.org>
CC: John Stultz <john.stultz@linaro.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>, Rik van Riel <riel@redhat.com>,
        Mel Gorman <mgorman@suse.de>,
        KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Anton Vorontsov <anton.vorontsov@linaro.org>,
        Pekka Enberg <penberg@kernel.org>,
        Wu Fengguang <fengguang.wu@intel.com>, Hugh Dickins <hughd@google.com>
Subject: Re: RFC:  Easy-Reclaimable LRU list
References: <4FE012CD.6010605@kernel.org> <4FE37434.808@linaro.org> <4FE41752.8050305@kernel.org>
In-Reply-To: <4FE41752.8050305@kernel.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1720
Lines: 55

(2012/06/22 15:57), Minchan Kim wrote:
> Hi John,
>
> On 06/22/2012 04:21 AM, John Stultz wrote:
>
>> On 06/18/2012 10:49 PM, Minchan Kim wrote:
>>> Hi everybody!
>>>
>>> Recently, there are some efforts to handle system memory pressure.
>>>
>>> 1) low memory notification - [1]
>>> 2) fallocate(VOLATILE) - [2]
>>> 3) fadvise(NOREUSE) - [3]
>>>
>>> For them, I would like to add new LRU list, aka "Ereclaimable" which
>>> is opposite of "unevictable".
>>> Reclaimable LRU list includes _easy_ reclaimable pages.
>>> For example, easy reclaimable pages are following as.
>>>
>>> 1. invalidated but remained LRU list.
>>> 2. pageout pages for reclaim(PG_reclaim pages)
>>> 3. fadvise(NOREUSE)
>>> 4. fallocate(VOLATILE)
>>>
>>> Their pages shouldn't stir normal LRU list and compaction might not
>>> migrate them, even.
>>> Reclaimer can reclaim Ereclaimable pages before normal lru list and
>>> will avoid unnecessary
>>> swapout in anon pages in easy-reclaimable LRU list.
>>
>> I was hoping there would be further comment on this by more core VM
>> devs, but so far things have been quiet (is everyone on vacation?).
>
>
> At least, there are no dissent comment until now.
> Let be a positive. :)

I think this is interesting approach. Major concern is how to guarantee EReclaimable
pages are really EReclaimable...Do you have any idea ? madviced pages are really
EReclaimable ?

A (very) small concern is will you use one more page-flags for this ? ;)

Thanks,
-Kame


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/