Mercurial > hg > graal-jvmci-8
changeset 1750:c7004d700b49
6978641: Fix for 6929067 introduces additional overhead in thread creation/termination paths
Summary: Disable stack bounds checks in product mode other than for the initial thread
Reviewed-by: coleenp, jcoomes, aph
author | dholmes |
---|---|
date | Wed, 25 Aug 2010 21:29:05 -0400 |
parents | ebfb7c68865e |
children | 2528b5bd749c |
files | src/os/linux/vm/os_linux.cpp |
diffstat | 1 files changed, 13 insertions(+), 4 deletions(-) [+] |
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--- a/src/os/linux/vm/os_linux.cpp Mon Aug 23 08:44:03 2010 -0700 +++ b/src/os/linux/vm/os_linux.cpp Wed Aug 25 21:29:05 2010 -0400 @@ -2597,10 +2597,14 @@ // where we're going to put our guard pages, truncate the mapping at // that point by munmap()ping it. This ensures that when we later // munmap() the guard pages we don't leave a hole in the stack -// mapping. +// mapping. This only affects the main/initial thread, but guard +// against future OS changes bool os::create_stack_guard_pages(char* addr, size_t size) { uintptr_t stack_extent, stack_base; - if (get_stack_bounds(&stack_extent, &stack_base)) { + bool chk_bounds = NOT_DEBUG(os::Linux::is_initial_thread()) DEBUG_ONLY(true); + if (chk_bounds && get_stack_bounds(&stack_extent, &stack_base)) { + assert(os::Linux::is_initial_thread(), + "growable stack in non-initial thread"); if (stack_extent < (uintptr_t)addr) ::munmap((void*)stack_extent, (uintptr_t)addr - stack_extent); } @@ -2609,10 +2613,15 @@ } // If this is a growable mapping, remove the guard pages entirely by -// munmap()ping them. If not, just call uncommit_memory(). +// munmap()ping them. If not, just call uncommit_memory(). This only +// affects the main/initial thread, but guard against future OS changes bool os::remove_stack_guard_pages(char* addr, size_t size) { uintptr_t stack_extent, stack_base; - if (get_stack_bounds(&stack_extent, &stack_base)) { + bool chk_bounds = NOT_DEBUG(os::Linux::is_initial_thread()) DEBUG_ONLY(true); + if (chk_bounds && get_stack_bounds(&stack_extent, &stack_base)) { + assert(os::Linux::is_initial_thread(), + "growable stack in non-initial thread"); + return ::munmap(addr, size) == 0; }