Re: [LKP] Re: [hugetlbfs] c0d0381ade: vm-scalability.throughput -33.4% regression

From: Xing Zhengjun
Date: Mon Oct 12 2020 - 22:42:08 EST




On 10/13/2020 1:40 AM, Mike Kravetz wrote:
On 10/11/20 10:29 PM, Xing Zhengjun wrote:
Hi Mike,

I re-test it in v5.9-rc8, the regression still existed. It is almost the same as 34ae204f1851. Do you have time to look at it? Thanks.


Thank you for testing.

Just curious, did you apply the series in this thread or just test v5.9-rc8?
If just testing v5.9-rc8, no changes to this code were added after 34ae204f1851,
so results being the same are expected.


I just test v5.9-rc8. Where can I find the series patches you mentioned here? Or just wait for the next mainline release?


There are some functional issues with this new hugetlb locking model that
are currently being worked. It is likely to result in significantly different
code. The performance issues discovered here will be taken into account with
the new code. However, as previously mentioned additional synchronization
is required for functional correctness. As a result, there will be some
regression in this code.


--
Zhengjun Xing