kiper220/mimalloc
1
0
Fork 0
mirror of https://github.com/microsoft/mimalloc.git synced 2025-07-01 09:14:38 +03:00
Code Issues Projects Releases Packages Wiki Activity Actions

Merge e784983b76 into 2d34956bed

Browse source
This commit is contained in:
Iurii Zakipnyi 2025-06-07 01:12:10 +02:00 • committed by GitHub
commit b024ed58da
WARNING! Although there is a key with this ID in the database it does not verify this commit! This commit is SUSPICIOUS.
GPG key ID: B5690EEEBB952194
1 changed files with 37 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

50
src/prim/unix/prim.c
View file

@ -430,13 +430,29 @@ int _mi_prim_commit(void* start, size_t size, bool* is_zero) {
err = errno;
unix_mprotect_hint(err);
}
#if defined(__APPLE__)
// MADV_FREE_REUSABLE is paired with MADV_FREE_REUSE for accounting
// if this memory was not marked as MADV_FREE_REUSABLE, this call is noop
madvise(start, size, MADV_FREE_REUSE);
#endif
return err;
}
int _mi_prim_decommit(void* start, size_t size, bool* needs_recommit) {
int err = 0;
// decommit: use MADV_DONTNEED as it decreases rss immediately (unlike MADV_FREE)
err = unix_madvise(start, size, MADV_DONTNEED);
#if defined(__APPLE__)
// On Apple platforms there is MADV_FREE_REUSABLE -- it marks memory as RESUABLE to reduce memory pressure.
int err = unix_madvise(start, size, MADV_FREE_REUSABLE);
if (err != 0) // if MADV_FREE_REUSABLE fails - fallback to MADV_DONTNEED
{
// use MADV_DONTNEED as it decreases rss immediately (unlike MADV_FREE)
err = unix_madvise(start, size, MADV_DONTNEED);
}
#else
// use MADV_DONTNEED as it decreases rss immediately (unlike MADV_FREE)
int err = unix_madvise(start, size, MADV_DONTNEED);
#endif
#if !MI_DEBUG && MI_SECURE<=2
*needs_recommit = false;
#else
@ -454,22 +470,30 @@ int _mi_prim_decommit(void* start, size_t size, bool* needs_recommit) {
}
int _mi_prim_reset(void* start, size_t size) {
int err = 0;
#if defined(__APPLE__)
// On Apple platforms there is MADV_FREE_REUSABLE -- it marks memory as RESUABLE to reduce memory pressure.
err = unix_madvise(start, size, MADV_FREE_REUSABLE);
if (err == 0)
return 0;
// if this fails - fallback to MADV_FREE/MADV_DONTNEED
#endif
// We try to use `MADV_FREE` as that is the fastest. A drawback though is that it
// will not reduce the `rss` stats in tools like `top` even though the memory is available
// to other processes. With the default `MIMALLOC_PURGE_DECOMMITS=1` we ensure that by
// default `MADV_DONTNEED` is used though.
#if defined(MADV_FREE)
static _Atomic(size_t) advice = MI_ATOMIC_VAR_INIT(MADV_FREE);
int oadvice = (int)mi_atomic_load_relaxed(&advice);
int err;
while ((err = unix_madvise(start, size, oadvice)) != 0 && errno == EAGAIN) { errno = 0; };
if (err != 0 && errno == EINVAL && oadvice == MADV_FREE) {
// if MADV_FREE is not supported, fall back to MADV_DONTNEED from now on
mi_atomic_store_release(&advice, (size_t)MADV_DONTNEED);
err = unix_madvise(start, size, MADV_DONTNEED);
}
static _Atomic(size_t) advice = MI_ATOMIC_VAR_INIT(MADV_FREE);
int oadvice = (int)mi_atomic_load_relaxed(&advice);
while ((err = unix_madvise(start, size, oadvice)) != 0 && errno == EAGAIN) { errno = 0; };
if (err != 0 && errno == EINVAL && oadvice == MADV_FREE) {
// if MADV_FREE is not supported, fall back to MADV_DONTNEED from now on
mi_atomic_store_release(&advice, (size_t)MADV_DONTNEED);
err = unix_madvise(start, size, MADV_DONTNEED);
}
#else
int err = unix_madvise(start, size, MADV_DONTNEED);
err = unix_madvise(start, size, MADV_DONTNEED);
#endif
return err;
}