Re: [PATCH] mm: extend zero pages to same element pages for zram

From	Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] mm: extend zero pages to same element pages for zram
Date	2017-01-23 08:20 +0100
Message-ID	<t2H50-3rt-3@gated-at.bofh.it> (permalink)
References	(2 earlier) <t1ZwZ-1Ri-1@gated-at.bofh.it> <t2gHw-3D7-11@gated-at.bofh.it> <t2D1o-CT-7@gated-at.bofh.it> <t2E78-1B0-11@gated-at.bofh.it> <t2GiB-2W5-9@gated-at.bofh.it>
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On (01/23/17 15:27), Joonsoo Kim wrote:
> Hello,
> 
> Think about following case in 64 bits kernel.
> 
> If value pattern in the page is like as following, we cannot detect
> the same page with 'unsigned int' element.
> 
> AAAAAAAABBBBBBBBAAAAAAAABBBBBBBB...
> 
> 4 bytes is 0xAAAAAAAA and next 4 bytes is 0xBBBBBBBB and so on.

yep, that's exactly the case that I though would be broken
with a 4-bytes pattern matching. so my conlusion was that
for 4 byte pattern we would have working detection anyway,
for 8 bytes patterns we might have some extra matching.
not sure if it matters that much though.

	-ss

Thread

Re: [PATCH] mm: extend zero pages to same element pages for zram Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-01-21 09:50 +0100
  Re: [PATCH] mm: extend zero pages to same element pages for zram zhouxianrong <zhouxianrong@huawei.com> - 2017-01-22 04:10 +0100
    Re: [PATCH] mm: extend zero pages to same element pages for zram Sergey Senozhatsky <sergey.senozhatsky@gmail.com> - 2017-01-22 06:00 +0100
    Re: [PATCH] mm: extend zero pages to same element pages for zram Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2017-01-23 04:00 +0100
      Re: [PATCH] mm: extend zero pages to same element pages for zram zhouxianrong <zhouxianrong@huawei.com> - 2017-01-23 04:40 +0100
      Re: [PATCH] mm: extend zero pages to same element pages for zram Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-01-23 05:10 +0100
        Re: [PATCH] mm: extend zero pages to same element pages for zram Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2017-01-23 07:30 +0100
          Re: [PATCH] mm: extend zero pages to same element pages for zram Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-01-23 08:20 +0100
            Re: [PATCH] mm: extend zero pages to same element pages for zram Minchan Kim <minchan@kernel.org> - 2017-01-23 08:50 +0100
              Re: [PATCH] mm: extend zero pages to same element pages for zram zhouxianrong <zhouxianrong@huawei.com> - 2017-01-24 09:30 +0100
                Re: [PATCH] mm: extend zero pages to same element pages for zram Minchan Kim <minchan@kernel.org> - 2017-01-25 02:30 +0100
                Re: [PATCH] mm: extend zero pages to same element pages for zram Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-01-25 02:40 +0100
                Re: [PATCH] mm: extend zero pages to same element pages for zram Matthew Wilcox <willy@infradead.org> - 2017-01-25 03:50 +0100
                Re: [PATCH] mm: extend zero pages to same element pages for zram Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-01-25 05:20 +0100
                Re: [PATCH] mm: extend zero pages to same element pages for zram Minchan Kim <minchan@kernel.org> - 2017-01-25 06:00 +0100
                Re: [PATCH] mm: extend zero pages to same element pages for zram Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-01-25 06:40 +0100
                Re: [PATCH] mm: extend zero pages to same element pages for zram Minchan Kim <minchan@kernel.org> - 2017-01-25 06:50 +0100
    Re: [PATCH] mm: extend zero pages to same element pages for zram Matthew Wilcox <willy@infradead.org> - 2017-01-23 07:30 +0100
      答复: [PATCH] mm: extend zero pages to same element pages for zram zhouxianrong <zhouxianrong@huawei.com> - 2017-01-23 07:50 +0100

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