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From:   "Huang\, Ying" <ying.huang@intel.com>
To:     Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Cc:     huang ying <huang.ying.caritas@gmail.com>,
        Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
        <linux-mm@kvack.org>
Subject: Re: kernel BUG at mm/swap_state.c:170!
References: <CABXGCsN9mYmBD-4GaaeW_NrDu+FDXLzr_6x+XNxfmFV6QkYCDg@mail.gmail.com>
        <CAC=cRTMz5S636Wfqdn3UGbzwzJ+v_M46_juSfoouRLS1H62orQ@mail.gmail.com>
        <CABXGCsOo-4CJicvTQm4jF4iDSqM8ic+0+HEEqP+632KfCntU+w@mail.gmail.com>
Date:   Mon, 22 Jul 2019 15:52:53 +0800
In-Reply-To: <CABXGCsOo-4CJicvTQm4jF4iDSqM8ic+0+HEEqP+632KfCntU+w@mail.gmail.com>
        (Mikhail Gavrilov's message of "Mon, 22 Jul 2019 12:31:36 +0500")
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Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> writes:

> On Mon, 22 Jul 2019 at 06:37, huang ying <huang.ying.caritas@gmail.com> wrote:
>>
>> I am trying to reproduce this bug.  Can you give me some information
>> about your test case?
>
> It not easy, but I try to explain:
>
> 1. I have the system with 32Gb RAM, 64GB swap and after boot, I always
> launch follow applications:
>     a. Google Chrome dev channel
>         Note: here you should have 3 windows full of tabs on my
> monitor 118 tabs in each window.
>         Don't worry modern Chrome browser is wise and load tabs only on demand.
>         We will use this feature later (on the last step).
>     b. Firefox Nightly ASAN this build with enabled address sanitizer.
>     c. Virtual Machine Manager (virt-manager) and start a virtual
> machine with Windows 10 (2048 MiB RAM allocated)
>     d. Evolution
>     e. Steam client
>     f. Telegram client
>     g. DeadBeef music player
>
> After all launched applications 15GB RAM should be allocated.
>
> 2. This step the most difficult, because we should by using Firefox
> allocated 27-28GB RAM.
>     I use the infinite scroll on sites Facebook, VK, Pinterest, Tumblr
> and open many tabs in Firefox as I could.
>     Note: our goal is 27-28GB allocated RAM in the system.
>
> 3. When we hit our goal in the second step now go to Google Chrome and
> click as fast as you can on all unloaded tabs.
>     As usual, after 60 tabs this issue usually happens. 100%
> reproducible for me.
>
> Of course, I tried to simplify my workflow case by using stress-ng but
> without success.
>
> I hope it will help to make autotests.

Yes.  This is quite complex.  Is the transparent huge page enabled in
your system?  You can check the output of

$ cat /sys/kernel/mm/transparent_hugepage/enabled

And, whether is the swap device you use a SSD or NVMe disk (not HDD)?

Best Regards,
Huang, Ying

> --
> Best Regards,
> Mike Gavrilov.