clarify needs_recommit

This commit is contained in:
daanx 2023-04-04 13:05:48 -07:00
parent 5c39fe7246
commit 1d231be758
5 changed files with 22 additions and 22 deletions

View file

@ -47,11 +47,11 @@ int _mi_prim_alloc(size_t size, size_t try_alignment, bool commit, bool allow_la
// For example, on Linux this would make the memory PROT_READ|PROT_WRITE.
int _mi_prim_commit(void* addr, size_t size);
// Decommit memory. Returns error code or 0 on success. The `decommitted` result is true
// Decommit memory. Returns error code or 0 on success. The `needs_recommit` result is true
// if the memory would need to be re-committed. For example, on Windows this is always true,
// but on Linux we could use MADV_DONTNEED to decommit which does not need a recommit.
// pre: decommitted != NULL
int _mi_prim_decommit(void* addr, size_t size, bool* decommitted);
// pre: needs_recommit != NULL
int _mi_prim_decommit(void* addr, size_t size, bool* needs_recommit);
// Reset memory. The range keeps being accessible but the content might be reset.
// Returns error code or 0 on success.

View file

@ -377,10 +377,10 @@ bool _mi_os_commit(void* addr, size_t size, bool* is_zero, mi_stats_t* tld_stats
return (err == 0);
}
static bool mi_os_decommit_ex(void* addr, size_t size, bool* decommitted, mi_stats_t* tld_stats) {
static bool mi_os_decommit_ex(void* addr, size_t size, bool* needs_recommit, mi_stats_t* tld_stats) {
MI_UNUSED(tld_stats);
mi_stats_t* stats = &_mi_stats_main;
mi_assert_internal(decommitted!=NULL);
mi_assert_internal(needs_recommit!=NULL);
_mi_stat_decrease(&stats->committed, size);
// page align
@ -389,8 +389,8 @@ static bool mi_os_decommit_ex(void* addr, size_t size, bool* decommitted, mi_sta
if (csize == 0) return true;
// decommit
*decommitted = true;
int err = _mi_prim_decommit(start,csize,decommitted);
*needs_recommit = true;
int err = _mi_prim_decommit(start,csize,needs_recommit);
if (err != 0) {
_mi_warning_message("cannot decommit OS memory (error: %d (0x%x), address: %p, size: 0x%zx bytes)\n", err, err, start, csize);
}
@ -399,8 +399,8 @@ static bool mi_os_decommit_ex(void* addr, size_t size, bool* decommitted, mi_sta
}
bool _mi_os_decommit(void* addr, size_t size, mi_stats_t* tld_stats) {
bool decommitted = true;
return mi_os_decommit_ex(addr, size, &decommitted, tld_stats);
bool needs_recommit;
return mi_os_decommit_ex(addr, size, &needs_recommit, tld_stats);
}
@ -427,18 +427,18 @@ bool _mi_os_reset(void* addr, size_t size, mi_stats_t* stats) {
}
// either resets or decommits memory, returns true if the memory was decommitted
// (in the sense that it needs to be re-committed if the memory is re-used later on).
// either resets or decommits memory, returns true if the memory needs
// to be recommitted if it is to be re-used later on.
bool _mi_os_purge(void* p, size_t size, mi_stats_t* stats)
{
if (!mi_option_is_enabled(mi_option_allow_purge)) return false;
if (mi_option_is_enabled(mi_option_purge_decommits) && // should decommit?
!_mi_preloading()) // don't decommit during preloading (unsafe)
!_mi_preloading()) // don't decommit during preloading (unsafe)
{
bool decommitted;
mi_os_decommit_ex(p, size, &decommitted, stats);
return decommitted;
bool needs_recommit;
mi_os_decommit_ex(p, size, &needs_recommit, stats);
return needs_recommit;
}
else {
_mi_os_reset(p, size, stats);

View file

@ -352,16 +352,16 @@ int _mi_prim_commit(void* start, size_t size) {
return err;
}
int _mi_prim_decommit(void* start, size_t size, bool* decommitted) {
int _mi_prim_decommit(void* start, size_t size, bool* needs_recommit) {
int err = 0;
#if defined(MADV_DONTNEED) && !MI_DEBUG && !MI_SECURE
// decommit: use MADV_DONTNEED as it decreases rss immediately (unlike MADV_FREE)
// (on the other hand, MADV_FREE would be good enough.. it is just not reflected in the stats :-( )
*decommitted = false;
*needs_recommit = false;
err = unix_madvise(start, size, MADV_DONTNEED);
#else
// decommit: just disable access (also used in debug and secure mode to trap on illegal access)
*decommitted = true; // needs recommit to reuse the memory
*needs_recommit = true; // needs recommit to reuse the memory
err = mprotect(start, size, PROT_NONE);
if (err != 0) { err = errno; }
#endif

View file

@ -131,9 +131,9 @@ int _mi_prim_commit(void* addr, size_t size) {
return 0;
}
int _mi_prim_decommit(void* addr, size_t size, bool* decommitted) {
int _mi_prim_decommit(void* addr, size_t size, bool* needs_recommit) {
MI_UNUSED(addr); MI_UNUSED(size);
*decommitted = false;
*needs_recommit = false;
return 0;
}

View file

@ -262,9 +262,9 @@ int _mi_prim_commit(void* addr, size_t size) {
return (p == addr ? 0 : (int)GetLastError());
}
int _mi_prim_decommit(void* addr, size_t size, bool* decommitted) {
int _mi_prim_decommit(void* addr, size_t size, bool* needs_recommit) {
BOOL ok = VirtualFree(addr, size, MEM_DECOMMIT);
*decommitted = true; // for safetly, assume always decommitted even in the case of an error.
*needs_recommit = true; // for safetly, assume always decommitted even in the case of an error.
return (ok ? 0 : (int)GetLastError());
}