[Merged by Bors] - Avoid cloning snapshots during sync #3271
Conversation
This file contains 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
michaelsproul
added
ready-for-review
michaelsproul
force-pushed
the
reduce-sync-clones
branch
from
71e9ab0
to
54d72d6
Compare
macladson
approved these changes
Jun 20, 2022
| @@ -253,7 +253,8 @@ impl<T: EthSpec> SnapshotCache<T> { | |||
| .position(|snapshot| snapshot.beacon_block_root == block_root) | |||
| .map(|i| { | |||
| if let Some(cache) = self.snapshots.get(i) { | |||
| if block_slot > cache.beacon_block.slot() + 1 { | |||
| // Avoid cloning the block during sync (when the `block_delay` is `None`). | |||
| if block_slot > cache.beacon_block.slot() + 1 && block_delay.is_some() { | |||
There was a problem hiding this comment.
Very very minor point in the case where block_delay is None:
If we nest this if block below into the if let Some block would it avoid us checking block_delay twice (assuming block_slot > cache.beacon_block.slot() + 1 == true)?
There was a problem hiding this comment.
yeah good call, that's simpler
michaelsproul
added
waiting-on-author
michaelsproul
force-pushed
the
reduce-sync-clones
branch
from
54d72d6
to
d68b1d3
Compare
michaelsproul
added
ready-for-merge
|
bors r+ |
bors bot
pushed a commit
that referenced
this pull request
Jun 20, 2022
## Issue Addressed Closes #2944 ## Proposed Changes Remove snapshots from the cache during sync rather than cloning them. This reduces unnecessary cloning and memory fragmentation during sync. ## Additional Info This PR relies on the fact that the `block_delay` cache is not populated for blocks from sync. Relying on block delay may have the side effect that a change in `block_delay` calculation could lead to: a) more clones, if block delays are added for syncing blocks or b) less clones, if blocks near the head are erroneously provided without a `block_delay`. Case (a) would be a regression to the current status quo, and (b) is low-risk given we know that the snapshot cache is current susceptible to misses (hence `tree-states`).
bors
bot
changed the title
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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.
Issue Addressed
Closes #2944
Proposed Changes
Remove snapshots from the cache during sync rather than cloning them. This reduces unnecessary cloning and memory fragmentation during sync.
Additional Info
This PR relies on the fact that the
block_delaycache is not populated for blocks from sync. Relying on block delay may have the side effect that a change inblock_delaycalculation could lead to: a) more clones, if block delays are added for syncing blocks or b) less clones, if blocks near the head are erroneously provided without ablock_delay. Case (a) would be a regression to the current status quo, and (b) is low-risk given we know that the snapshot cache is current susceptible to misses (hencetree-states).