Attachment #433509 for bug #227957

View Details Raw Unified Return to Bug 227957



2021-07-14  Michael Saboff  <msaboff@apple.com>

        [BMalloc] Lazily allocate physical pages
        https://bugs.webkit.org/show_bug.cgi?id=227957

        Reviewed by NOBODY (OOPS!).

        For Darwin platform we don't need to call madvise(..., MADV_FREE_REUSE) to commit physical
        memory to back an range of allocated virtual memory.  Instead the kernel will commit pages
        as they are touched.  This can reduce the footprint of a process when there is sparse access
        of allocated memory.

        Also fixed a minor bug where we allocate memory, but don't update the amount of physical memory
        associated with it.

        * bmalloc/Heap.cpp:
        (bmalloc::Heap::tryAllocateLargeChunk):
        * bmalloc/VMAllocate.h:
        (bmalloc::vmAllocatePhysicalPages):

2021-07-12  Filip Pizlo  <fpizlo@apple.com> and Yusuke Suzuki  <ysuzuki@apple.com>

        New malloc algorithm

Lines 586-592 LargeRange Heap::tryAllocateLargeChunk(s Source/bmalloc/bmalloc/Heap.cpp_sec1
- Source/bmalloc/bmalloc/Heap.cpp -1 / +1 lines
586	PerProcess<Zone>::get()->addRange(Range(memory, size));	586	PerProcess<Zone>::get()->addRange(Range(memory, size));
587	#endif	587	#endif
588		588
589	return LargeRange(memory, size, 0, 0, memory);	589	return LargeRange(memory, size, size, size, static_cast<char*>(memory) + size);
590	}	590	}
591		591
592	size_t Heap::largeSize(UniqueLockHolder&, void* object)	592	size_t Heap::largeSize(UniqueLockHolder&, void* object)




inline void vmAllocatePhysicalPages(void* p, size_t vmSize)
{
    vmValidatePhysical(p, vmSize);
#if BOS(DARWIN)
    BUNUSED_PARAM(p);
    BUNUSED_PARAM(vmSize);
#else
    vmValidatePhysical(p, vmSize);
    SYSCALL(madvise(p, vmSize, MADV_NORMAL));
#if BOS(LINUX)
    SYSCALL(madvise(p, vmSize, MADV_DODUMP));

Return to Bug 227957

Lines 213-222 inline void vmDeallocatePhysicalPages(vo Source/bmalloc/bmalloc/VMAllocate.h_sec1
- Source/bmalloc/bmalloc/VMAllocate.h -2 / +3 lines
213		213
214	inline void vmAllocatePhysicalPages(void* p, size_t vmSize)	214	inline void vmAllocatePhysicalPages(void* p, size_t vmSize)
215	{	215	{
216	vmValidatePhysical(p, vmSize);
217	#if BOS(DARWIN)	216	#if BOS(DARWIN)
218	SYSCALL(madvise(p, vmSize, MADV_FREE_REUSE));	217	BUNUSED_PARAM(p);
		218	BUNUSED_PARAM(vmSize);
219	#else	219	#else
		220	vmValidatePhysical(p, vmSize);
220	SYSCALL(madvise(p, vmSize, MADV_NORMAL));	221	SYSCALL(madvise(p, vmSize, MADV_NORMAL));
221	#if BOS(LINUX)	222	#if BOS(LINUX)
222	SYSCALL(madvise(p, vmSize, MADV_DODUMP));	223	SYSCALL(madvise(p, vmSize, MADV_DODUMP));

Lines 1-3 Source/bmalloc/ChangeLog_sec1
- Source/bmalloc/ChangeLog +20 lines
		1	2021-07-14 Michael Saboff <msaboff@apple.com>
		2
		3	[BMalloc] Lazily allocate physical pages
		4	https://bugs.webkit.org/show_bug.cgi?id=227957
		5
		6	Reviewed by NOBODY (OOPS!).
		7
		8	For Darwin platform we don't need to call madvise(..., MADV_FREE_REUSE) to commit physical
		9	memory to back an range of allocated virtual memory. Instead the kernel will commit pages
		10	as they are touched. This can reduce the footprint of a process when there is sparse access
		11	of allocated memory.
		12
		13	Also fixed a minor bug where we allocate memory, but don't update the amount of physical memory
		14	associated with it.
		15
		16	* bmalloc/Heap.cpp:
		17	(bmalloc::Heap::tryAllocateLargeChunk):
		18	* bmalloc/VMAllocate.h:
		19	(bmalloc::vmAllocatePhysicalPages):
		20
1	2021-07-12 Filip Pizlo <fpizlo@apple.com> and Yusuke Suzuki <ysuzuki@apple.com>	21	2021-07-12 Filip Pizlo <fpizlo@apple.com> and Yusuke Suzuki <ysuzuki@apple.com>
2		22
3	New malloc algorithm	23	New malloc algorithm