add a thp-based huge page alloc fallback

[pcsx_rearmed.git] / libpcsxcore / psxmem.c

diff --git a/libpcsxcore/psxmem.c b/libpcsxcore/psxmem.c
index 54219ae..389bdba 100644 (file)
--- a/libpcsxcore/psxmem.c
+++ b/libpcsxcore/psxmem.c
@@ -44,15 +44,39 @@
 static void * psxMapDefault(unsigned long addr, size_t size,
                            int is_fixed, enum psxMapTag tag)
 {
+       void *ptr;
+#if !P_HAVE_MMAP
+       ptr = calloc(1, size);
+       return ptr ? ptr : MAP_FAILED;
+#else
        int flags = MAP_PRIVATE | MAP_ANONYMOUS;
 
-       return mmap((void *)(uintptr_t)addr, size,
+       ptr = mmap((void *)(uintptr_t)addr, size,
                    PROT_READ | PROT_WRITE, flags, -1, 0);
+#ifdef MADV_HUGEPAGE
+       if (size >= 2*1024*1024) {
+               if (ptr != MAP_FAILED && ((uintptr_t)ptr & (2*1024*1024 - 1))) {
+                       // try to manually realign assuming bottom-to-top alloc
+                       munmap(ptr, size);
+                       addr = (uintptr_t)ptr & ~(2*1024*1024 - 1);
+                       ptr = mmap((void *)(uintptr_t)addr, size,
+                               PROT_READ | PROT_WRITE, flags, -1, 0);
+               }
+               if (ptr != MAP_FAILED)
+                       madvise(ptr, size, MADV_HUGEPAGE);
+       }
+#endif
+       return ptr;
+#endif
 }
 
 static void psxUnmapDefault(void *ptr, size_t size, enum psxMapTag tag)
 {
+#if !P_HAVE_MMAP
+       free(ptr);
+#else
        munmap(ptr, size);
+#endif
 }
 
 void *(*psxMapHook)(unsigned long addr, size_t size, int is_fixed,