[host_memory] decrease latency of mapping on linux

Signed-off-by: lizzie <lizzie@eden-emu.dev>
This commit is contained in:
lizzie 2025-08-09 04:04:22 +01:00 committed by crueter
parent c36cc0d3ee
commit dc65e6fc15

View file

@ -606,12 +606,17 @@ public:
bool ClearBackingRegion(size_t physical_offset, size_t length) { bool ClearBackingRegion(size_t physical_offset, size_t length) {
#ifdef __linux__ #ifdef __linux__
// Set MADV_REMOVE on backing map to destroy it instantly. // Only incur syscall cost IF memset would be slower (theshold = 16MiB)
// This also deletes the area from the backing file. // TODO(lizzie): Smarter way to dynamically get this threshold (broadwell != raptor lake) for example
int ret = madvise(backing_base + physical_offset, length, MADV_REMOVE); if (length >= 2097152UL * 8) {
ASSERT_MSG(ret == 0, "madvise failed: {}", strerror(errno)); // Set MADV_REMOVE on backing map to destroy it instantly.
// This also deletes the area from the backing file.
return true; int ret = madvise(backing_base + physical_offset, length, MADV_REMOVE);
ASSERT_MSG(ret == 0, "madvise failed: {}", strerror(errno));
return true;
} else {
return false;
}
#else #else
return false; return false;
#endif #endif