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| author | Cupertino Miranda <cupertino.miranda@oracle.com> | 2023-04-14 16:12:20 +0100 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2023-04-20 13:54:24 -0300 |
| commit | b630be0922dbaaa50eb174a7740f0d3fb88602da (patch) | |
| tree | fa0e6bd1ef8115117c6a2090b2dd5248269609fb /manual | |
| parent | 0f61cd4b9c5175c128311769df932c8d7694d6b6 (diff) | |
| download | glibc-b630be0922dbaaa50eb174a7740f0d3fb88602da.zip glibc-b630be0922dbaaa50eb174a7740f0d3fb88602da.tar.gz glibc-b630be0922dbaaa50eb174a7740f0d3fb88602da.tar.bz2 | |
Created tunable to force small pages on stack allocation.
Created tunable glibc.pthread.stack_hugetlb to control when hugepages
can be used for stack allocation.
In case THP are enabled and glibc.pthread.stack_hugetlb is set to
0, glibc will madvise the kernel not to use allow hugepages for stack
allocations.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diffstat (limited to 'manual')
| -rw-r--r-- | manual/tunables.texi | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/manual/tunables.texi b/manual/tunables.texi index 70dd226..130f94b 100644 --- a/manual/tunables.texi +++ b/manual/tunables.texi @@ -459,6 +459,21 @@ registration on behalf of the application. Restartable sequences are a Linux-specific extension. @end deftp +@deftp Tunable glibc.pthread.stack_hugetlb +This tunable controls whether to use Huge Pages in the stacks created by +@code{pthread_create}. This tunable only affects the stacks created by +@theglibc{}, it has no effect on stack assigned with +@code{pthread_attr_setstack}. + +The default is @samp{1} where the system default value is used. Setting +its value to @code{0} enables the use of @code{madvise} with +@code{MADV_NOHUGEPAGE} after stack creation with @code{mmap}. + +This is a memory utilization optimization, since internal glibc setup of either +the thread descriptor and the guard page might force the kernel to move the +thread stack originally backup by Huge Pages to default pages. +@end deftp + @node Hardware Capability Tunables @section Hardware Capability Tunables @cindex hardware capability tunables |