8076614: Add comment to ClearNoncleanCardWrapper::do_MemRegion()

Reviewed-by: kbarrett, stefank
This commit is contained in:
Bengt Rutisson 2015-04-08 09:35:25 +02:00
parent 7ec8aadd33
commit d86a561fe4

View file

@ -180,6 +180,10 @@ bool ClearNoncleanCardWrapper::is_word_aligned(jbyte* entry) {
return (((intptr_t)entry) & (BytesPerWord-1)) == 0;
}
// The regions are visited in *decreasing* address order.
// This order aids with imprecise card marking, where a dirty
// card may cause scanning, and summarization marking, of objects
// that extend onto subsequent cards.
void ClearNoncleanCardWrapper::do_MemRegion(MemRegion mr) {
assert(mr.word_size() > 0, "Error");
assert(_ct->is_aligned(mr.start()), "mr.start() should be card aligned");