Reduce critical section in findEviction (for heterogenous memory cache) #73
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
igchor
force-pushed
the
optimize_mmcontainer_locking_hetero
branch
3 times, most recently
from
c6e0fd2 to
ec20142
Compare
Remove the item from mmContainer and drop the lock before attempting eviction. Use moving bit for synchronization in findEviction moving bit is used to give exclusive right to evict the item to a particular thread. Originially, there was an assumption that whoever marked the item as moving will try to free it until he succeeds. Since we don't want to do that in findEviction (potentially can take a long time) we need to make sure that unmarking is safe. This patch checks the flags after unmarking (atomically) and if ref is zero it also recyles the item. This is needed as there might be some concurrent thread releasing the item (and decrementing ref count). If moving bit is set, that thread would not free the memory back to allocator, resulting in memory leak on unmarkMoving().
igchor
force-pushed
the
optimize_mmcontainer_locking_hetero
branch
2 times, most recently
from
8938190 to
0f2fe81
Compare
igchor
force-pushed
the
optimize_mmcontainer_locking_hetero
branch
from
ebff039 to
ed2af50
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This change is