Implement rosalloc page trimming without suspending threads.
Also, making it more efficient by not going through the chunks smaller
than the page size by not using InspectAll().
Change-Id: I79ceb0374cb8aba5f6b8dde1afbace9af98b6cff
diff --git a/runtime/gc/allocator/rosalloc.cc b/runtime/gc/allocator/rosalloc.cc
index 920741f..cbefa6a 100644
--- a/runtime/gc/allocator/rosalloc.cc
+++ b/runtime/gc/allocator/rosalloc.cc
@@ -2005,6 +2005,61 @@
}
}
+size_t RosAlloc::ReleasePages() {
+ VLOG(heap) << "RosAlloc::ReleasePages()";
+ DCHECK(!DoesReleaseAllPages());
+ Thread* self = Thread::Current();
+ size_t reclaimed_bytes = 0;
+ size_t i = 0;
+ while (true) {
+ MutexLock mu(self, lock_);
+ // Check the page map size which might have changed due to grow/shrink.
+ size_t pm_end = page_map_size_;
+ if (i >= pm_end) {
+ // Reached the end.
+ break;
+ }
+ byte pm = page_map_[i];
+ switch (pm) {
+ case kPageMapEmpty: {
+ // The start of a free page run. Release pages.
+ FreePageRun* fpr = reinterpret_cast<FreePageRun*>(base_ + i * kPageSize);
+ DCHECK(free_page_runs_.find(fpr) != free_page_runs_.end());
+ size_t fpr_size = fpr->ByteSize(this);
+ DCHECK(IsAligned<kPageSize>(fpr_size));
+ byte* start = reinterpret_cast<byte*>(fpr);
+ if (kIsDebugBuild) {
+ // In the debug build, the first page of a free page run
+ // contains a magic number for debugging. Exclude it.
+ start = reinterpret_cast<byte*>(fpr) + kPageSize;
+ }
+ byte* end = reinterpret_cast<byte*>(fpr) + fpr_size;
+ CHECK_EQ(madvise(start, end - start, MADV_DONTNEED), 0);
+ reclaimed_bytes += fpr_size;
+ size_t num_pages = fpr_size / kPageSize;
+ if (kIsDebugBuild) {
+ for (size_t j = i + 1; j < i + num_pages; ++j) {
+ DCHECK_EQ(page_map_[j], kPageMapEmpty);
+ }
+ }
+ i += num_pages;
+ DCHECK_LE(i, pm_end);
+ break;
+ }
+ case kPageMapLargeObject: // Fall through.
+ case kPageMapLargeObjectPart: // Fall through.
+ case kPageMapRun: // Fall through.
+ case kPageMapRunPart: // Fall through.
+ ++i;
+ break; // Skip.
+ default:
+ LOG(FATAL) << "Unreachable - page map type: " << pm;
+ break;
+ }
+ }
+ return reclaimed_bytes;
+}
+
} // namespace allocator
} // namespace gc
} // namespace art
diff --git a/runtime/gc/allocator/rosalloc.h b/runtime/gc/allocator/rosalloc.h
index 0b4b189..5d9d75c 100644
--- a/runtime/gc/allocator/rosalloc.h
+++ b/runtime/gc/allocator/rosalloc.h
@@ -539,6 +539,8 @@
void InspectAll(void (*handler)(void* start, void* end, size_t used_bytes, void* callback_arg),
void* arg)
LOCKS_EXCLUDED(lock_);
+ // Release empty pages.
+ size_t ReleasePages() LOCKS_EXCLUDED(lock_);
// Returns the current footprint.
size_t Footprint() LOCKS_EXCLUDED(lock_);
// Returns the current capacity, maximum footprint.
diff --git a/runtime/gc/space/rosalloc_space.cc b/runtime/gc/space/rosalloc_space.cc
index 012267b..5c5e7f8 100644
--- a/runtime/gc/space/rosalloc_space.cc
+++ b/runtime/gc/space/rosalloc_space.cc
@@ -222,6 +222,7 @@
}
size_t RosAllocSpace::Trim() {
+ VLOG(heap) << "RosAllocSpace::Trim() ";
{
MutexLock mu(Thread::Current(), lock_);
// Trim to release memory at the end of the space.
@@ -229,10 +230,7 @@
}
// Attempt to release pages if it does not release all empty pages.
if (!rosalloc_->DoesReleaseAllPages()) {
- VLOG(heap) << "RosAllocSpace::Trim() ";
- size_t reclaimed = 0;
- InspectAllRosAlloc(DlmallocMadviseCallback, &reclaimed, false);
- return reclaimed;
+ return rosalloc_->ReleasePages();
}
return 0;
}