Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1349782

Re: Suspicious error for CMA stress test

From Joonsoo Kim <iamjoonsoo.kim@lge.com>
Newsgroups linux.kernel
Subject Re: Suspicious error for CMA stress test
Date 2016-03-04 03:10 +0100
Message-ID <r8NlM-801-9@gated-at.bofh.it> (permalink)
References <r8ftO-8on-33@gated-at.bofh.it> <r8qfw-84R-17@gated-at.bofh.it> <r8wbh-3Mh-39@gated-at.bofh.it> <r8B1h-7eH-17@gated-at.bofh.it> <r8GDE-2P0-19@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw

On Thu, Mar 03, 2016 at 10:52:17AM -0800, Laura Abbott wrote:
> On 03/03/2016 04:49 AM, Hanjun Guo wrote:
> >On 2016/3/3 15:42, Joonsoo Kim wrote:
> >>2016-03-03 10:25 GMT+09:00 Laura Abbott <labbott@redhat.com>:
> >>>(cc -mm and Joonsoo Kim)
> >>>
> >>>
> >>>On 03/02/2016 05:52 AM, Hanjun Guo wrote:
> >>>>Hi,
> >>>>
> >>>>I came across a suspicious error for CMA stress test:
> >>>>
> >>>>Before the test, I got:
> >>>>-bash-4.3# cat /proc/meminfo | grep Cma
> >>>>CmaTotal:         204800 kB
> >>>>CmaFree:          195044 kB
> >>>>
> >>>>
> >>>>After running the test:
> >>>>-bash-4.3# cat /proc/meminfo | grep Cma
> >>>>CmaTotal:         204800 kB
> >>>>CmaFree:         6602584 kB
> >>>>
> >>>>So the freed CMA memory is more than total..
> >>>>
> >>>>Also the the MemFree is more than mem total:
> >>>>
> >>>>-bash-4.3# cat /proc/meminfo
> >>>>MemTotal:       16342016 kB
> >>>>MemFree:        22367268 kB
> >>>>MemAvailable:   22370528 kB
> >[...]
> >>>
> >>>I played with this a bit and can see the same problem. The sanity
> >>>check of CmaFree < CmaTotal generally triggers in
> >>>__move_zone_freepage_state in unset_migratetype_isolate.
> >>>This also seems to be present as far back as v4.0 which was the
> >>>first version to have the updated accounting from Joonsoo.
> >>>Were there known limitations with the new freepage accounting,
> >>>Joonsoo?
> >>I don't know. I also played with this and looks like there is
> >>accounting problem, however, for my case, number of free page is slightly less
> >>than total. I will take a look.
> >>
> >>Hanjun, could you tell me your malloc_size? I tested with 1 and it doesn't
> >>look like your case.
> >
> >I tested with malloc_size with 2M, and it grows much bigger than 1M, also I
> >did some other test:
> >
> >  - run with single thread with 100000 times, everything is fine.
> >
> >  - I hack the cam_alloc() and free as below [1] to see if it's lock issue, with
> >    the same test with 100 multi-thread, then I got:
> >
> >-bash-4.3# cat /proc/meminfo | grep Cma
> >CmaTotal: 204800 kB
> >CmaFree: 225112 kB
> >
> >It only increased about 30M for free, not 6G+ in previous test, although
> >the problem is not solved, the problem is less serious, is it a synchronization
> >problem?
> >
> 
> 'only' 30M is still an issue although I think you are right about something related
> to synchronization. When I put the cma_mutex around free_contig_range I don't see

Hmm... I can see the issue even if putting the cma_mutex around
free_contig_range().

In other reply, I attached the code to temporary close the race.

> the issue. I wonder if free of the pages is racing with the undo_isolate_page_range
> on overlapping ranges caused by outer_start?

I don't know yet.
Anyway, it looks like that the problem that I want to fix by commit '3c60509'
still remains.

Thanks.

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Suspicious error for CMA stress test Hanjun Guo <guohanjun@huawei.com> - 2016-03-02 15:00 +0100
  Re: Suspicious error for CMA stress test Laura Abbott <labbott@redhat.com> - 2016-03-03 02:30 +0100
    Re: Suspicious error for CMA stress test Hanjun Guo <guohanjun@huawei.com> - 2016-03-03 07:30 +0100
    Re: Suspicious error for CMA stress test Joonsoo Kim <js1304@gmail.com> - 2016-03-03 08:50 +0100
      Re: Suspicious error for CMA stress test Hanjun Guo <guohanjun@huawei.com> - 2016-03-03 09:00 +0100
      Re: Suspicious error for CMA stress test Hanjun Guo <guohanjun@huawei.com> - 2016-03-03 14:00 +0100
        Re: Suspicious error for CMA stress test Laura Abbott <labbott@redhat.com> - 2016-03-03 20:00 +0100
          Re: Suspicious error for CMA stress test Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-03-04 03:10 +0100
            Re: Suspicious error for CMA stress test Hanjun Guo <guohanjun@huawei.com> - 2016-03-04 07:20 +0100
        Re: Suspicious error for CMA stress test Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-03-04 03:10 +0100
          Re: Suspicious error for CMA stress test Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-03-04 05:40 +0100
            Re: Suspicious error for CMA stress test Hanjun Guo <guohanjun@huawei.com> - 2016-03-04 07:10 +0100
              Re: Suspicious error for CMA stress test Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-03-04 07:40 +0100
                Re: Suspicious error for CMA stress test Hanjun Guo <guohanjun@huawei.com> - 2016-03-04 08:40 +0100
                Re: Suspicious error for CMA stress test Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-03-07 05:40 +0100
                Re: Suspicious error for CMA stress test "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com> - 2016-03-07 09:20 +0100
                Re: Suspicious error for CMA stress test Laura Abbott <labbott@redhat.com> - 2016-03-07 19:50 +0100
                Re: Suspicious error for CMA stress test "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com> - 2016-03-08 03:00 +0100
                Re: Suspicious error for CMA stress test "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com> - 2016-03-09 02:30 +0100
                Re: Suspicious error for CMA stress test Joonsoo Kim <js1304@gmail.com> - 2016-03-11 16:10 +0100
                Re: Suspicious error for CMA stress test Vlastimil Babka <vbabka@suse.cz> - 2016-03-11 18:10 +0100
                Re: Suspicious error for CMA stress test Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-03-14 07:50 +0100
                Re: Suspicious error for CMA stress test Vlastimil Babka <vbabka@suse.cz> - 2016-03-14 08:10 +0100
                Re: Suspicious error for CMA stress test Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-03-14 08:20 +0100
                Re: Suspicious error for CMA stress test Vlastimil Babka <vbabka@suse.cz> - 2016-03-14 13:40 +0100
                Re: Suspicious error for CMA stress test Joonsoo Kim <js1304@gmail.com> - 2016-03-14 15:20 +0100
                Re: Suspicious error for CMA stress test Vlastimil Babka <vbabka@suse.cz> - 2016-03-16 13:10 +0100
                Re: Suspicious error for CMA stress test Hanjun Guo <guohanjun@huawei.com> - 2016-03-16 10:50 +0100
                Re: Suspicious error for CMA stress test Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-03-17 08:00 +0100
                Re: Suspicious error for CMA stress test Hanjun Guo <guohanjun@huawei.com> - 2016-03-17 10:30 +0100
                Re: Suspicious error for CMA stress test Joonsoo Kim <js1304@gmail.com> - 2016-03-17 16:40 +0100
                Re: Suspicious error for CMA stress test Vlastimil Babka <vbabka@suse.cz> - 2016-03-17 16:50 +0100
                Re: Suspicious error for CMA stress test Joonsoo Kim <js1304@gmail.com> - 2016-03-17 17:00 +0100
                Re: Suspicious error for CMA stress test Hanjun Guo <hanjun.guo@linaro.org> - 2016-03-08 05:10 +0100
                Re: Suspicious error for CMA stress test Vlastimil Babka <vbabka@suse.cz> - 2016-03-07 14:00 +0100
                Re: Suspicious error for CMA stress test Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-03-08 08:50 +0100
                Re: Suspicious error for CMA stress test Xishi Qiu <qiuxishi@huawei.com> - 2016-03-08 11:50 +0100
                Re: Suspicious error for CMA stress test Joonsoo Kim <js1304@gmail.com> - 2016-03-08 16:40 +0100
                Re: Suspicious error for CMA stress test Xishi Qiu <qiuxishi@huawei.com> - 2016-03-09 03:20 +0100
          Re: Suspicious error for CMA stress test Hanjun Guo <guohanjun@huawei.com> - 2016-03-04 06:40 +0100
            Re: Suspicious error for CMA stress test Xishi Qiu <qiuxishi@huawei.com> - 2016-03-08 02:50 +0100
              Re: Suspicious error for CMA stress test Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-03-08 09:10 +0100
          Re: Suspicious error for CMA stress test Hanjun Guo <guohanjun@huawei.com> - 2016-03-04 08:10 +0100
            Re: Suspicious error for CMA stress test Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2016-03-07 05:50 +0100

csiph-web