From afad979c60e4b54b65a6fd7345d476076a7a9a03 Mon Sep 17 00:00:00 2001 From: Bob Weinand Date: Sat, 7 Mar 2015 13:07:18 +0100 Subject: [PATCH] Reduced initial VM_STACK page size of Generators to 4 KB (256 slots) Generators all have their own vm_stack, but usually don't go really deep. In most cases even most of the 4 KB will remain unused (in my tests average is rather 1 KB), but this was tested a straightforward implementation without a lot of abstraction layers. That way I'm using a more conservative 4 KB stack size which really should be enough for, I think, at least 90% of the cases. This was necessary to not immediately run out of memory with 95%+ usused vm_stack space: If you have a few thousands of Generators active, your application quickly hits memory_limit with a stack page size of 256 KB... In addition, it's also a bit faster (70% less instructions for zend_vm_stack_new_page) due to emalloc() not having to allocate a whole new segment (segment size 256 KB). Also no mmap()/malloc() necessary. --- Zend/zend_execute.c | 35 +++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-) diff --git a/Zend/zend_execute.c b/Zend/zend_execute.c index 4dd8e2c6b2..1609e7367c 100644 --- a/Zend/zend_execute.c +++ b/Zend/zend_execute.c @@ -123,15 +123,18 @@ static const zend_internal_function zend_pass_function = { #define DECODE_CTOR(ce) \ ((zend_class_entry*)(((zend_uintptr_t)(ce)) & ~(CTOR_CALL_BIT|CTOR_USED_BIT))) -#define ZEND_VM_STACK_PAGE_SLOTS (16 * 1024) /* should be a power of 2 */ +#define ZEND_VM_MAIN_STACK_PAGE_SLOTS (16 * 1024) /* should be a power of 2 */ +#define ZEND_VM_GENERATOR_STACK_PAGE_SLOTS (256) -#define ZEND_VM_STACK_PAGE_SIZE (ZEND_VM_STACK_PAGE_SLOTS * sizeof(zval)) +#define ZEND_VM_STACK_PAGE_SLOTS(gen) ((gen) ? ZEND_VM_GENERATOR_STACK_PAGE_SLOTS : ZEND_VM_MAIN_STACK_PAGE_SLOTS) -#define ZEND_VM_STACK_FREE_PAGE_SIZE \ - ((ZEND_VM_STACK_PAGE_SLOTS - ZEND_VM_STACK_HEADER_SLOTS) * sizeof(zval)) +#define ZEND_VM_STACK_PAGE_SIZE(gen) (ZEND_VM_STACK_PAGE_SLOTS(gen) * sizeof(zval)) -#define ZEND_VM_STACK_PAGE_ALIGNED_SIZE(size) \ - (((size) + (ZEND_VM_STACK_FREE_PAGE_SIZE - 1)) & ~ZEND_VM_STACK_PAGE_SIZE) +#define ZEND_VM_STACK_FREE_PAGE_SIZE(gen) \ + ((ZEND_VM_STACK_PAGE_SLOTS(gen) - ZEND_VM_STACK_HEADER_SLOTS) * sizeof(zval)) + +#define ZEND_VM_STACK_PAGE_ALIGNED_SIZE(gen, size) \ + (((size) + (ZEND_VM_STACK_FREE_PAGE_SIZE(gen) - 1)) & ~ZEND_VM_STACK_PAGE_SIZE(gen)) static zend_always_inline zend_vm_stack zend_vm_stack_new_page(size_t size, zend_vm_stack prev) { zend_vm_stack page = (zend_vm_stack)emalloc(size); @@ -144,7 +147,7 @@ static zend_always_inline zend_vm_stack zend_vm_stack_new_page(size_t size, zend ZEND_API void zend_vm_stack_init(void) { - EG(vm_stack) = zend_vm_stack_new_page(ZEND_VM_STACK_PAGE_SIZE, NULL); + EG(vm_stack) = zend_vm_stack_new_page(ZEND_VM_STACK_PAGE_SIZE(0 /* main stack */), NULL); EG(vm_stack)->top++; EG(vm_stack_top) = EG(vm_stack)->top; EG(vm_stack_end) = EG(vm_stack)->end; @@ -163,14 +166,14 @@ ZEND_API void zend_vm_stack_destroy(void) ZEND_API void* zend_vm_stack_extend(size_t size) { - zend_vm_stack stack; - void *ptr; + zend_vm_stack stack; + void *ptr; - stack = EG(vm_stack); - stack->top = EG(vm_stack_top); + stack = EG(vm_stack); + stack->top = EG(vm_stack_top); EG(vm_stack) = stack = zend_vm_stack_new_page( - EXPECTED(size < ZEND_VM_STACK_FREE_PAGE_SIZE) ? - ZEND_VM_STACK_PAGE_SIZE : ZEND_VM_STACK_PAGE_ALIGNED_SIZE(size), + EXPECTED(size < ZEND_VM_STACK_FREE_PAGE_SIZE(0)) ? + ZEND_VM_STACK_PAGE_SIZE(0) : ZEND_VM_STACK_PAGE_ALIGNED_SIZE(0, size), stack); ptr = stack->top; EG(vm_stack_top) = (void*)(((char*)ptr) + size); @@ -1934,9 +1937,9 @@ ZEND_API zend_execute_data *zend_create_generator_execute_data(zend_execute_data size_t stack_size = (ZEND_CALL_FRAME_SLOT + MAX(op_array->last_var + op_array->T, num_args)) * sizeof(zval); EG(vm_stack) = zend_vm_stack_new_page( - EXPECTED(stack_size < ZEND_VM_STACK_FREE_PAGE_SIZE) ? - ZEND_VM_STACK_PAGE_SIZE : - ZEND_VM_STACK_PAGE_ALIGNED_SIZE(stack_size), + EXPECTED(stack_size < ZEND_VM_STACK_FREE_PAGE_SIZE(1)) ? + ZEND_VM_STACK_PAGE_SIZE(1) : + ZEND_VM_STACK_PAGE_ALIGNED_SIZE(1, stack_size), NULL); EG(vm_stack_top) = EG(vm_stack)->top; EG(vm_stack_end) = EG(vm_stack)->end; -- 2.40.0