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On Darwin, using MADV_FREE_REUSABLE/MADV_FREE_REUSE.

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The former to notify the pages are available for other processes,
 the latter is needed for proper counting in case those pages where
tagged as reusable previously otherwise is a no-op, all for better
 RSS reporting for task_info apps.
This commit is contained in:
David Carlier 2020-10-31 22:22:04 +00:00
parent ca13e9cd59
commit 1deea03bf1
1 changed files with 12 additions and 1 deletions
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13
src/os.c
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@ -435,7 +435,7 @@ static void* mi_unix_mmap(void* addr, size_t size, size_t try_alignment, int pro
// though since properly aligned allocations will already use large pages if available
// in that case -- in particular for our large regions (in `memory.c`).
// However, some systems only allow THP if called with explicit `madvise`, so
// when large OS pages are enabled for mimalloc, we call `madvice` anyways.
// when large OS pages are enabled for mimalloc, we call `madvise` anyways.
if (allow_large && use_large_os_page(size, try_alignment)) {
if (madvise(p, size, MADV_HUGEPAGE) == 0) {
*is_large = true; // possibly
@ -721,6 +721,9 @@ static bool mi_os_commitx(void* addr, size_t size, bool commit, bool conservativ
// for commit, just change the protection
err = mprotect(start, csize, (PROT_READ | PROT_WRITE));
if (err != 0) { err = errno; }
#if defined(MADV_FREE_REUSE)
while ((err = madvise(start, csize, MADV_FREE_REUSE)) != 0 && errno == EAGAIN) {}
#endif
}
#else
err = mprotect(start, csize, (commit ? (PROT_READ | PROT_WRITE) : PROT_NONE));
@ -782,9 +785,17 @@ static bool mi_os_resetx(void* addr, size_t size, bool reset, mi_stats_t* stats)
if (p != start) return false;
#else
#if defined(MADV_FREE)
#if defined(MADV_FREE_REUSABLE)
static _Atomic(uintptr_t) advice = ATOMIC_VAR_INIT(MADV_FREE_REUSABLE);
int oadvice = (int)mi_atomic_load_relaxed(&advice);
int err;
while ((err = madvise(start, csize, oadvice)) != 0 && errno == EAGAIN) {}
if (err != 0 && errno == EINVAL && advice == MADV_FREE_REUSABLE) {
#else
static _Atomic(uintptr_t) advice = ATOMIC_VAR_INIT(MADV_FREE);
int err = madvise(start, csize, (int)mi_atomic_load_relaxed(&advice));
if (err != 0 && errno == EINVAL && advice == MADV_FREE) {
#endif
// if MADV_FREE is not supported, fall back to MADV_DONTNEED from now on
mi_atomic_store_release(&advice, (uintptr_t)MADV_DONTNEED);
err = madvise(start, csize, MADV_DONTNEED);