[prev in list] [next in list] [prev in thread] [next in thread] 

List:       openjdk-hotspot-runtime-dev
Subject:    Integrated: 8324776: runtime/os/TestTransparentHugePageUsage.java fails with The usage of THP is not
From:       Liming Liu <duke () openjdk ! org>
Date:       2024-04-29 15:17:11
Message-ID: mhmMW95S8phl0hv69D05k3sJRSjcRhk5HRLFUnJhzJs=.8daacda9-303b-45e1-b302-ef2dd171ad30 () github ! com
[Download RAW message or body]

On Tue, 16 Apr 2024 08:57:48 GMT, Liming Liu <duke@openjdk.org> wrote:

> This PR remove the testcase introduced in JDK-8315923, as we could not find a \
> reliable way to evaluate the usage of THP. We have tried the following methods: 
> 1. transverse /proc/self/smaps rather than looking up the first map covered by the \
> heap, as we found there can be multiple sections in /proc/self/smaps for the heap; \
> (https://github.com/limingliu-ampere/jdk/commit/c5b0c4cdf9fa42988faa9fee6ee004ebb599d40a)
>  2. take the mode of de-fragment and the enabling of khugepaged into account rather \
> than just THP mode, as THP may not be available immediately when the de-fragment \
> mode is neither "always" nor "madvise", or khugepaged does not collapse pages; \
> (https://github.com/limingliu-ampere/jdk/commit/9c70e9384325b44e074a9e8973846343b27fd2cc)
>  3. call madvise with MADV_HUGEPAGE unconditionally rather than calling it only \
> when THP mode is not "always", and adjust the sizes of young and old generations to \
> ensure the parameters are aligned with THP; \
> (https://github.com/limingliu-ampere/jdk/commit/de9607ff64cc526bca9968b72a7065888c2f944d)
>  4. check the changes of system-wide counters like thp_* in /proc/vmstat before and \
> after pretouch via gtest. \
> (https://github.com/limingliu-ampere/jdk/commit/bc83e19a682156ee7d09bf939c2b18f3d8c79e22)
>  
> But none of them helps. The amount of THP keeps zero on Oracle CI, although the THP \
> mode is "always", the de-fragment mode is "madvise" and khugepaged is enabled. \
> Furthermore, none of thp counters changed around pretouch. However, we tried the \
> same kernel (5.15-UEK) as Oracle CI on our machine, and found that these methods do \
> help. Thus, we decided to remove this testcase.

This pull request has now been integrated.

Changeset: 8b8fb642
Author:    Liming Liu <limingliu@os.amperecomputing.com>
Committer: Thomas Stuefe <stuefe@openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/8b8fb6427e3cbc16b818ddcbd6a971f3d2370f94
                
Stats:     106 lines in 2 files changed: 0 ins; 106 del; 0 mod

8324776: runtime/os/TestTransparentHugePageUsage.java fails with The usage of THP is \
not enough

Reviewed-by: stuefe

-------------

PR: https://git.openjdk.org/jdk/pull/18792


[prev in list] [next in list] [prev in thread] [next in thread]