Re: [PATCH v4 1/4] mm: fix tracing in free_pcppages_bulk()

[Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>]

Hi Minchan,

2012/09/19 16:32, Minchan Kim wrote:
> Hi Yasuaki,
>
> On Wed, Sep 19, 2012 at 04:07:19PM +0900, Yasuaki Ishimatsu wrote:
>> Hi Bartlomiej,
>>
>> 2012/09/14 23:29, Bartlomiej Zolnierkiewicz wrote:
>>> page->private gets re-used in __free_one_page() to store page order
>>> (so trace_mm_page_pcpu_drain() may print order instead of migratetype)
>>> thus migratetype value must be cached locally.
>>>
>>> Fixes regression introduced in a701623 ("mm: fix migratetype bug
>>> which slowed swapping").
>>
>> I think the regression has been alreadly fixed by following Mincahn's patches.
>>
>> https://lkml.org/lkml/2012/9/6/635
>>
>> => Hi Minchan,
>>
>>     Am I wrong?
>
> This patch isn't related to mine.

According to the description, the regression occurs by clearing migratetype
info from page->private at __free_one_page(). If we apply your patches,
migratetype info is stored into page->index. So the migratetype info is not
cleared. Thus we do not need to cache the info locally.

Thanks,
Yasuaki Ishimatsu

> In addition, this patch don't need to be a part of this series.
>



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