From: Xishi Qiu <qiuxishi@huawei.com>
To: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: zhong jiang <zhongjiang@huawei.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>, Aaron Lu <aaron.lu@intel.com>,
Mel Gorman <mgorman@suse.de>, Rik van Riel <riel@redhat.com>,
David Rientjes <rientjes@google.com>,
LKML <linux-kernel@vger.kernel.org>,
Linux Memory Management List <linux-mm@kvack.org>
Subject: Re: [PATCH v2 3/3] mm/compaction: speed up pageblock_pfn_to_page() when zone is contiguous
Date: Mon, 15 Feb 2016 18:06:08 +0800 [thread overview]
Message-ID: <56C1A310.9090305@huawei.com> (raw)
In-Reply-To: <20160215024220.GA30918@js1304-P5Q-DELUXE>
On 2016/2/15 10:42, Joonsoo Kim wrote:
>>
>> I have a question about the zone continuity. because hole exists at
>> arbitrary position in a page block. Therefore, only pageblock_pf_to_page()
>> is insufficiency, whether pageblock aligned pfn or not , the pfn_valid_within()
>> is necessary.
>>
>> eh: 120M-122M is a range of page block, but the 120.5M-121.5M is holes, only by
>> pageblock_pfn_to_page() to conclude in the result is inaccurate
>
> contiguous may be misleading word. It doesn't represent there are no
> hole. It only represents that all pageblocks within zone span belong to
> corresponding zone and validity of all pageblock aligned pfn is
> checked. So, if it is set, we can safely call pfn_to_page() for pageblock
> aligned pfn in that zone without checking pfn_valid().
>
> Thanks.
>
Hi Joonsoo,
So "contiguous" here only means that struct page is exist, and don't care whether
the memory is exist, right?
Thanks,
Xishi Qiu
>
> .
>
next prev parent reply other threads:[~2016-02-15 10:06 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-04 6:19 [PATCH v2 1/3] mm/compaction: fix invalid free_pfn and compact_cached_free_pfn Joonsoo Kim
2016-02-04 6:19 ` [PATCH v2 2/3] mm/compaction: pass only pageblock aligned range to pageblock_pfn_to_page Joonsoo Kim
2016-02-10 12:52 ` Vlastimil Babka
2016-02-04 6:19 ` [PATCH v2 3/3] mm/compaction: speed up pageblock_pfn_to_page() when zone is contiguous Joonsoo Kim
2016-02-05 0:49 ` Andrew Morton
2016-02-05 16:11 ` Joonsoo Kim
2016-02-09 17:58 ` Vlastimil Babka
2016-02-09 20:53 ` Andrew Morton
2016-02-10 13:42 ` Vlastimil Babka
2016-02-10 18:58 ` Andrew Morton
2016-02-11 1:58 ` Joonsoo Kim
2016-02-14 10:21 ` zhong jiang
2016-02-15 2:42 ` Joonsoo Kim
2016-02-15 10:06 ` Xishi Qiu [this message]
2016-02-15 14:24 ` Joonsoo Kim
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