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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 /nptl | |
| 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 'nptl')
| -rw-r--r-- | nptl/allocatestack.c | 6 | ||||
| -rw-r--r-- | nptl/nptl-stack.c | 1 | ||||
| -rw-r--r-- | nptl/nptl-stack.h | 3 | ||||
| -rw-r--r-- | nptl/pthread_mutex_conf.c | 8 |
4 files changed, 18 insertions, 0 deletions
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c index c7adbcc..f9d8cdf 100644 --- a/nptl/allocatestack.c +++ b/nptl/allocatestack.c @@ -369,6 +369,12 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, if (__glibc_unlikely (mem == MAP_FAILED)) return errno; + /* Do madvise in case the tunable glibc.pthread.stack_hugetlb is + set to 0, disabling hugetlb. */ + if (__glibc_unlikely (__nptl_stack_hugetlb == 0) + && __madvise (mem, size, MADV_NOHUGEPAGE) != 0) + return errno; + /* SIZE is guaranteed to be greater than zero. So we can never get a null pointer back from mmap. */ assert (mem != NULL); diff --git a/nptl/nptl-stack.c b/nptl/nptl-stack.c index 5eb7773..e829711 100644 --- a/nptl/nptl-stack.c +++ b/nptl/nptl-stack.c @@ -21,6 +21,7 @@ #include <pthreadP.h> size_t __nptl_stack_cache_maxsize = 40 * 1024 * 1024; +int32_t __nptl_stack_hugetlb = 1; void __nptl_stack_list_del (list_t *elem) diff --git a/nptl/nptl-stack.h b/nptl/nptl-stack.h index 34f8bbb..cf90b27 100644 --- a/nptl/nptl-stack.h +++ b/nptl/nptl-stack.h @@ -27,6 +27,9 @@ /* Maximum size of the cache, in bytes. 40 MiB by default. */ extern size_t __nptl_stack_cache_maxsize attribute_hidden; +/* Should allow stacks to use hugetlb. (1) is default. */ +extern int32_t __nptl_stack_hugetlb; + /* Check whether the stack is still used or not. */ static inline bool __nptl_stack_in_use (struct pthread *pd) diff --git a/nptl/pthread_mutex_conf.c b/nptl/pthread_mutex_conf.c index 9133384..6517899 100644 --- a/nptl/pthread_mutex_conf.c +++ b/nptl/pthread_mutex_conf.c @@ -44,6 +44,12 @@ TUNABLE_CALLBACK (set_stack_cache_size) (tunable_val_t *valp) __nptl_stack_cache_maxsize = valp->numval; } +static void +TUNABLE_CALLBACK (set_stack_hugetlb) (tunable_val_t *valp) +{ + __nptl_stack_hugetlb = (int32_t) valp->numval; +} + void __pthread_tunables_init (void) { @@ -51,4 +57,6 @@ __pthread_tunables_init (void) TUNABLE_CALLBACK (set_mutex_spin_count)); TUNABLE_GET (stack_cache_size, size_t, TUNABLE_CALLBACK (set_stack_cache_size)); + TUNABLE_GET (stack_hugetlb, int32_t, + TUNABLE_CALLBACK (set_stack_hugetlb)); } |