8087339: The code heap might use different alignment for committed size and reserved size
Summary: InitialCodeCacheSize should not constrain code cache memory alignment.
Reviewed-by: kvn
--- a/src/hotspot/share/code/codeCache.cpp Mon Nov 27 11:39:21 2017 +0100
+++ b/src/hotspot/share/code/codeCache.cpp Mon Nov 27 11:41:00 2017 +0100
@@ -282,10 +282,11 @@
FLAG_SET_ERGO(uintx, ProfiledCodeHeapSize, profiled_size);
FLAG_SET_ERGO(uintx, NonProfiledCodeHeapSize, non_profiled_size);
- // Align CodeHeaps
- size_t alignment = heap_alignment();
+ // If large page support is enabled, align code heaps according to large
+ // page size to make sure that code cache is covered by large pages.
+ const size_t alignment = MAX2(page_size(false), (size_t) os::vm_allocation_granularity());
non_nmethod_size = align_up(non_nmethod_size, alignment);
- profiled_size = align_down(profiled_size, alignment);
+ profiled_size = align_down(profiled_size, alignment);
// Reserve one continuous chunk of memory for CodeHeaps and split it into
// parts for the individual heaps. The memory layout looks like this:
@@ -308,38 +309,29 @@
add_heap(non_profiled_space, "CodeHeap 'non-profiled nmethods'", CodeBlobType::MethodNonProfiled);
}
-size_t CodeCache::heap_alignment() {
- // If large page support is enabled, align code heaps according to large
- // page size to make sure that code cache is covered by large pages.
- const size_t page_size = os::can_execute_large_page_memory() ?
- os::page_size_for_region_unaligned(ReservedCodeCacheSize, 8) :
- os::vm_page_size();
- return MAX2(page_size, (size_t) os::vm_allocation_granularity());
+size_t CodeCache::page_size(bool aligned) {
+ if (os::can_execute_large_page_memory()) {
+ return aligned ? os::page_size_for_region_aligned(ReservedCodeCacheSize, 8) :
+ os::page_size_for_region_unaligned(ReservedCodeCacheSize, 8);
+ } else {
+ return os::vm_page_size();
+ }
}
ReservedCodeSpace CodeCache::reserve_heap_memory(size_t size) {
- // Determine alignment
- const size_t page_size = os::can_execute_large_page_memory() ?
- MIN2(os::page_size_for_region_aligned(InitialCodeCacheSize, 8),
- os::page_size_for_region_aligned(size, 8)) :
- os::vm_page_size();
- const size_t granularity = os::vm_allocation_granularity();
- const size_t r_align = MAX2(page_size, granularity);
- const size_t r_size = align_up(size, r_align);
- const size_t rs_align = page_size == (size_t) os::vm_page_size() ? 0 :
- MAX2(page_size, granularity);
-
- ReservedCodeSpace rs(r_size, rs_align, rs_align > 0);
-
+ // Align and reserve space for code cache
+ const size_t rs_ps = page_size();
+ const size_t rs_align = MAX2(rs_ps, (size_t) os::vm_allocation_granularity());
+ const size_t rs_size = align_up(size, rs_align);
+ ReservedCodeSpace rs(rs_size, rs_align, rs_ps > (size_t) os::vm_page_size());
if (!rs.is_reserved()) {
vm_exit_during_initialization(err_msg("Could not reserve enough space for code cache (" SIZE_FORMAT "K)",
- r_size/K));
+ rs_size/K));
}
// Initialize bounds
_low_bound = (address)rs.base();
_high_bound = _low_bound + rs.size();
-
return rs;
}
--- a/src/hotspot/share/code/codeCache.hpp Mon Nov 27 11:39:21 2017 +0100
+++ b/src/hotspot/share/code/codeCache.hpp Mon Nov 27 11:41:00 2017 +0100
@@ -107,7 +107,7 @@
static CodeHeap* get_code_heap(int code_blob_type); // Returns the CodeHeap for the given CodeBlobType
// Returns the name of the VM option to set the size of the corresponding CodeHeap
static const char* get_code_heap_flag_name(int code_blob_type);
- static size_t heap_alignment(); // Returns the alignment of the CodeHeaps in bytes
+ static size_t page_size(bool aligned = true); // Returns the page size used by the CodeCache
static ReservedCodeSpace reserve_heap_memory(size_t size); // Reserves one continuous chunk of memory for the CodeHeaps
// Iteration