lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Wed, 20 Dec 2017 18:21:40 +0800
From:   kemi <>
To:     Michal Hocko <>
Cc:     Greg Kroah-Hartman <>,
        Andrew Morton <>,
        Vlastimil Babka <>,
        Mel Gorman <>,
        Johannes Weiner <>,
        Christopher Lameter <>,
        Andrey Ryabinin <>,
        Nikolay Borisov <>,
        Pavel Tatashin <>,
        David Rientjes <>,
        Sebastian Andrzej Siewior <>,
        Dave <>,
        Andi Kleen <>,
        Tim Chen <>,
        Jesper Dangaard Brouer <>,
        Ying Huang <>,
        Aaron Lu <>, Aubrey Li <>,
        Linux MM <>,
        Linux Kernel <>
Subject: Re: [PATCH v2 3/5] mm: enlarge NUMA counters threshold size

On 2017年12月20日 18:12, Michal Hocko wrote:
> On Wed 20-12-17 13:52:14, kemi wrote:
>> On 2017年12月19日 20:40, Michal Hocko wrote:
>>> On Tue 19-12-17 14:39:24, Kemi Wang wrote:
>>>> We have seen significant overhead in cache bouncing caused by NUMA counters
>>>> update in multi-threaded page allocation. See 'commit 1d90ca897cb0 ("mm:
>>>> update NUMA counter threshold size")' for more details.
>>>> This patch updates NUMA counters to a fixed size of (MAX_S16 - 2) and deals
>>>> with global counter update using different threshold size for node page
>>>> stats.
>>> Again, no numbers.
>> Compare to vanilla kernel, I don't think it has performance improvement, so
>> I didn't post performance data here.
>> But, if you would like to see performance gain from enlarging threshold size
>> for NUMA stats (compare to the first patch), I will do that later. 
> Please do. I would also like to hear _why_ all counters cannot simply
> behave same. In other words why we cannot simply increase
> stat_threshold? Maybe calculate_normal_threshold needs a better scaling
> for larger machines.

Agree. We may consider that.
But, unlike NUMA counters which do not effect system decision.
We need consider very carefully when increase stat_threshold for all the counters
for larger machines. BTW, this is another topic that we may discuss it in different

Powered by blists - more mailing lists