[webkit-changes] [WebKit/WebKit] 0014f2: Reduce PGM Metadata Storage from 64 to 40 bytes pe...

[Brandon Stewart]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 0014f22cde494c9382d376d0cf89c9d56cf03a04
      https://github.com/WebKit/WebKit/commit/0014f22cde494c9382d376d0cf89c9d56cf03a04
  Author: Brandon Stewart <brandonstewart at apple.com>
  Date:   2023-03-06 (Mon, 06 Mar 2023)

  Changed paths:
    M Source/bmalloc/libpas/src/libpas/pas_enumerate_large_heaps.c
    M Source/bmalloc/libpas/src/libpas/pas_probabilistic_guard_malloc_allocator.c
    M Source/bmalloc/libpas/src/libpas/pas_probabilistic_guard_malloc_allocator.h

  Log Message:
  -----------
  Reduce PGM Metadata Storage from 64 to 40 bytes per allocation
https://bugs.webkit.org/show_bug.cgi?id=253458

Reviewed by Yusuke Suzuki.

Decrease metadata storage significantly per allocation when performing a PGM allocation.
This is a solid first pass, but we can probably optimize the page_size entry a bit.

* Source/bmalloc/libpas/src/libpas/pas_enumerate_large_heaps.c:
(pas_hash_map_entry_callback):
* Source/bmalloc/libpas/src/libpas/pas_probabilistic_guard_malloc_allocator.c:
(pas_probabilistic_guard_malloc_allocate):
(pas_probabilistic_guard_malloc_deallocate):
(pas_probabilistic_guard_malloc_debug_info):
* Source/bmalloc/libpas/src/libpas/pas_probabilistic_guard_malloc_allocator.h:

Canonical link: https://commits.webkit.org/261305@main