diff options
author | Peter Zhu <peter@peterzhu.ca> | 2021-05-05 21:06:56 +0000 |
---|---|---|
committer | Peter Zhu <peter@peterzhu.ca> | 2021-05-05 17:54:26 -0400 |
commit | b655a3fa5b8d1a30565e19425c28a1cfd8631165 (patch) | |
tree | ff2a196987f2776e9ba0877e330eea321c7bb0b7 /gc.c | |
parent | 23a98237df28ad01d17b163eb650dfbd321b13ba (diff) |
Fall back to sysconf to determine page size during runtime
On some platforms the PAGE_SIZE macro does not exist so we can fall back
to `sysconf` to determine the page size at runtime.
Notes
Notes:
Merged: https://github.com/ruby/ruby/pull/4462
Diffstat (limited to 'gc.c')
-rw-r--r-- | gc.c | 16 |
1 files changed, 14 insertions, 2 deletions
@@ -835,10 +835,12 @@ enum { #define HEAP_PAGE_ALIGN (1 << HEAP_PAGE_ALIGN_LOG) #define HEAP_PAGE_SIZE HEAP_PAGE_ALIGN -#if defined(HAVE_MMAP) && defined(PAGE_SIZE) +#ifdef HAVE_MMAP # if HAVE_CONST_PAGE_SIZE +/* If we have the HEAP_PAGE and it is a constant, then we can directly use it. */ # define USE_MMAP_ALIGNED_ALLOC (PAGE_SIZE <= HEAP_PAGE_SIZE) # else +/* Otherwise, fall back to determining if we can use mmap during runtime. */ # define USE_MMAP_ALIGNED_ALLOC (use_mmap_aligned_alloc != false) static bool use_mmap_aligned_alloc; @@ -3208,8 +3210,18 @@ Init_heap(void) { rb_objspace_t *objspace = &rb_objspace; -#if defined(HAVE_MMAP) && defined(PAGE_SIZE) && !HAVE_CONST_PAGE_SIZE +#if defined(HAVE_MMAP) && !HAVE_CONST_PAGE_SIZE + /* Need to determine if we can use mmap at runtime. */ +# ifdef PAGE_SIZE + /* If the PAGE_SIZE macro can be used. */ use_mmap_aligned_alloc = PAGE_SIZE <= HEAP_PAGE_SIZE; +# elif defined(HAVE_SYSCONF) && defined(_SC_PAGE_SIZE) + /* If we can use sysconf to determine the page size. */ + use_mmap_aligned_alloc = sysconf(_SC_PAGE_SIZE) <= HEAP_PAGE_SIZE; +# else + /* Otherwise we can't determine the system page size, so don't use mmap. */ + use_mmap_aligned_alloc = FALSE; +# endif #endif #if defined(HAVE_SYSCONF) && defined(_SC_PAGE_SIZE) |