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add reset_decommit, reset_discard options; maintain more statistics

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This commit is contained in:
daan 2019-07-09 20:24:00 -07:00
parent 2cfdbc2cbb
commit 0314373d93
7 changed files with 142 additions and 96 deletions
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126
src/os.c
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@ -391,29 +391,74 @@ static void* mi_os_page_align_area_conservative(void* addr, size_t size, size_t*
return mi_os_page_align_areax(true, addr, size, newsize);
}
// Commit/Decommit memory. Commit is aligned liberal, while decommit is aligned conservative.
static bool mi_os_commitx(void* addr, size_t size, bool commit, mi_stats_t* stats) {
// page align in the range, commit liberally, decommit conservative
size_t csize;
void* start = mi_os_page_align_areax(!commit, addr, size, &csize);
if (csize == 0) return true;
int err = 0;
if (commit) {
_mi_stat_increase(&stats->committed, csize);
_mi_stat_increase(&stats->commit_calls, 1);
}
else {
_mi_stat_decrease(&stats->committed, csize);
}
#if defined(_WIN32)
if (commit) {
void* p = VirtualAlloc(start, csize, MEM_COMMIT, PAGE_READWRITE);
err = (p == start ? 0 : GetLastError());
}
else {
BOOL ok = VirtualFree(start, csize, MEM_DECOMMIT);
err = (ok ? 0 : GetLastError());
}
#else
err = mprotect(start, csize, (commit ? (PROT_READ | PROT_WRITE) : PROT_NONE));
#endif
if (err != 0) {
_mi_warning_message("commit/decommit error: start: 0x%8p, csize: 0x%8zux, err: %i\n", start, csize, err);
}
mi_assert_internal(err == 0);
return (err == 0);
}
bool _mi_os_commit(void* addr, size_t size, mi_stats_t* stats) {
return mi_os_commitx(addr, size, true, stats);
}
bool _mi_os_decommit(void* addr, size_t size, mi_stats_t* stats) {
return mi_os_commitx(addr, size, false, stats);
}
// Signal to the OS that the address range is no longer in use
// but may be used later again. This will release physical memory
// pages and reduce swapping while keeping the memory committed.
// We page align to a conservative area inside the range to reset.
bool _mi_os_reset(void* addr, size_t size, mi_stats_t* stats) {
static bool mi_os_resetx(void* addr, size_t size, bool reset, mi_stats_t* stats) {
// page align conservatively within the range
size_t csize;
void* start = mi_os_page_align_area_conservative(addr, size, &csize);
if (csize == 0) return true;
_mi_stat_increase(&stats->reset, csize);
if (reset) _mi_stat_increase(&stats->reset, csize);
else _mi_stat_decrease(&stats->reset, csize);
if (!reset) return true; // nothing to do on unreset!
#if defined(_WIN32)
// Testing shows that for us (on `malloc-large`) MEM_RESET is 2x faster than DiscardVirtualMemory
// (but this is for an access pattern that immediately reuses the memory)
/*
DWORD ok = DiscardVirtualMemory(start, csize);
return (ok != 0);
*/
void* p = VirtualAlloc(start, csize, MEM_RESET, PAGE_READWRITE);
mi_assert(p == start);
if (p != start) return false;
if (mi_option_is_enabled(mi_option_reset_discards)) {
DWORD ok = DiscardVirtualMemory(start, csize);
mi_assert_internal(ok == 0);
if (ok != 0) return false;
}
else {
void* p = VirtualAlloc(start, csize, MEM_RESET, PAGE_READWRITE);
mi_assert_internal(p == start);
if (p != start) return false;
}
/*
// VirtualUnlock removes the memory eagerly from the current working set (which MEM_RESET does lazily on demand)
// TODO: put this behind an option?
@ -441,6 +486,29 @@ bool _mi_os_reset(void* addr, size_t size, mi_stats_t* stats) {
#endif
}
// Signal to the OS that the address range is no longer in use
// but may be used later again. This will release physical memory
// pages and reduce swapping while keeping the memory committed.
// We page align to a conservative area inside the range to reset.
bool _mi_os_reset(void* addr, size_t size, mi_stats_t* stats) {
if (mi_option_is_enabled(mi_option_reset_decommits)) {
return _mi_os_decommit(addr,size,stats);
}
else {
return mi_os_resetx(addr, size, true, stats);
}
}
bool _mi_os_unreset(void* addr, size_t size, mi_stats_t* stats) {
if (mi_option_is_enabled(mi_option_reset_decommits)) {
return _mi_os_commit(addr, size, stats); // re-commit it
}
else {
return mi_os_resetx(addr, size, false, stats);
}
}
// Protect a region in memory to be not accessible.
static bool mi_os_protectx(void* addr, size_t size, bool protect) {
// page align conservatively within the range
@ -470,47 +538,7 @@ bool _mi_os_unprotect(void* addr, size_t size) {
return mi_os_protectx(addr, size, false);
}
// Commit/Decommit memory. Commit is aligned liberal, while decommit is aligned conservative.
static bool mi_os_commitx(void* addr, size_t size, bool commit, mi_stats_t* stats) {
// page align in the range, commit liberally, decommit conservative
size_t csize;
void* start = mi_os_page_align_areax(!commit, addr, size, &csize);
if (csize == 0) return true;
int err = 0;
if (commit) {
_mi_stat_increase(&stats->committed, csize);
_mi_stat_increase(&stats->commit_calls, 1);
}
else {
_mi_stat_decrease(&stats->committed, csize);
}
#if defined(_WIN32)
if (commit) {
void* p = VirtualAlloc(start, csize, MEM_COMMIT, PAGE_READWRITE);
err = (p == start ? 0 : GetLastError());
}
else {
BOOL ok = VirtualFree(start, csize, MEM_DECOMMIT);
err = (ok ? 0 : GetLastError());
}
#else
err = mprotect(start, csize, (commit ? (PROT_READ | PROT_WRITE) : PROT_NONE));
#endif
if (err != 0) {
_mi_warning_message("commit/decommit error: start: 0x%8p, csize: 0x%8zux, err: %i\n", start, csize, err);
}
mi_assert_internal(err == 0);
return (err == 0);
}
bool _mi_os_commit(void* addr, size_t size, mi_stats_t* stats) {
return mi_os_commitx(addr, size, true, stats);
}
bool _mi_os_decommit(void* addr, size_t size, mi_stats_t* stats) {
return mi_os_commitx(addr, size, false, stats);
}
bool _mi_os_shrink(void* p, size_t oldsize, size_t newsize, mi_stats_t* stats) {
// page align conservatively within the range