Re: [PATCH v7 00/12] Support non-lru page migration

From	Minchan Kim <minchan@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v7 00/12] Support non-lru page migration
Date	2016-06-16 12:10 +0200
Message-ID	<rKCpj-72x-5@gated-at.bofh.it> (permalink)
References	(5 earlier) <rKx6h-3Bp-21@gated-at.bofh.it> <rKxpD-3Jz-5@gated-at.bofh.it> <rKy2l-4dk-7@gated-at.bofh.it> <rKzhL-4S6-3@gated-at.bofh.it> <rKB9T-62Y-9@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Thu, Jun 16, 2016 at 05:42:11PM +0900, Sergey Senozhatsky wrote:
> On (06/16/16 15:47), Minchan Kim wrote:
> > > [..]
> > > > > this is what I'm getting with the [zsmalloc: keep first object offset in struct page]
> > > > > applied:  "count:0 mapcount:-127". which may be not related to zsmalloc at this point.
> > > > > 
> > > > > kernel: BUG: Bad page state in process khugepaged  pfn:101db8
> > > > > kernel: page:ffffea0004076e00 count:0 mapcount:-127 mapping:          (null) index:0x1
> > > > 
> > > > Hm, it seems double free.
> > > > 
> > > > It doen't happen if you disable zram? IOW, it seems to be related
> > > > zsmalloc migration?
> > > 
> > > need to test more, can't confidently answer now.
> > > 
> > > > How easy can you reprodcue it? Could you bisect it?
> > > 
> > > it takes some (um.. random) time to trigger the bug.
> > > I'll try to come up with more details.
> > 
> > Could you revert [1] and retest?
> > 
> > [1] mm/compaction: split freepages without holding the zone lock
> 
> ok, so this is not related to zsmalloc. finally manged to reproduce
> it. will fork a separate thread.

The reason I mentioned [1] is that it seems to have a bug.

isolate_freepages_block
  __isolate_free_page
    if(!zone_watermark_ok())
      return 0;
  list_add_tail(&page->lru, freelist);

However, the page is not isolated.
Joonsoo?

Thread

Re: [PATCH v7 00/12] Support non-lru page migration Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2016-06-15 10:00 +0200
  Re: [PATCH v7 00/12] Support non-lru page migration Minchan Kim <minchan@kernel.org> - 2016-06-16 01:20 +0200
    Re: [PATCH v7 00/12] Support non-lru page migration Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2016-06-16 04:50 +0200
      Re: [PATCH v7 00/12] Support non-lru page migration Minchan Kim <minchan@kernel.org> - 2016-06-16 05:00 +0200
        Re: [PATCH v7 00/12] Support non-lru page migration Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2016-06-16 06:30 +0200
          Re: [PATCH v7 00/12] Support non-lru page migration Minchan Kim <minchan@kernel.org> - 2016-06-16 06:50 +0200
            Re: [PATCH v7 00/12] Support non-lru page migration Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2016-06-16 07:30 +0200
              Re: [PATCH v7 00/12] Support non-lru page migration Minchan Kim <minchan@kernel.org> - 2016-06-16 08:50 +0200
                Re: [PATCH v7 00/12] Support non-lru page migration Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2016-06-16 10:50 +0200
                Re: [PATCH v7 00/12] Support non-lru page migration Minchan Kim <minchan@kernel.org> - 2016-06-16 12:10 +0200
                Re: [PATCH v7 00/12] Support non-lru page migration Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-06-17 09:30 +0200

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