archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-08-27 06:45:07 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

7121547: G1: High number mispredicted branches while iterating over the marking bitmap

Browse source 
There is a high number of mispredicted branches associated with calling BitMap::iteratate() from within CMBitMapRO::iterate(). Implement a version of CMBitMapRO::iterate() directly using inline-able routines.

Reviewed-by: tonyp, iveresov
This commit is contained in:
John Cuthbertson 2012-01-13 13:27:48 -08:00
parent 1b06646e3f
commit dac656c955
4 changed files with 56 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

29
hotspot/src/share/vm/gc_implementation/g1/concurrentMark.inline.hpp
View file

@ -28,6 +28,35 @@
#include "gc_implementation/g1/concurrentMark.hpp"
#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
inline bool CMBitMapRO::iterate(BitMapClosure* cl, MemRegion mr) {
HeapWord* start_addr = MAX2(startWord(), mr.start());
HeapWord* end_addr = MIN2(endWord(), mr.end());
if (end_addr > start_addr) {
// Right-open interval [start-offset, end-offset).
BitMap::idx_t start_offset = heapWordToOffset(start_addr);
BitMap::idx_t end_offset = heapWordToOffset(end_addr);
start_offset = _bm.get_next_one_offset(start_offset, end_offset);
while (start_offset < end_offset) {
HeapWord* obj_addr = offsetToHeapWord(start_offset);
oop obj = (oop) obj_addr;
if (!cl->do_bit(start_offset)) {
return false;
}
HeapWord* next_addr = MIN2(obj_addr + obj->size(), end_addr);
BitMap::idx_t next_offset = heapWordToOffset(next_addr);
start_offset = _bm.get_next_one_offset(next_offset, end_offset);
}
}
return true;
}
inline bool CMBitMapRO::iterate(BitMapClosure* cl) {
MemRegion mr(startWord(), sizeInWords());
return iterate(cl, mr);
}
inline void CMTask::push(oop obj) {
HeapWord* objAddr = (HeapWord*) obj;
assert(_g1h->is_in_g1_reserved(objAddr), "invariant");