hbt/bperf: Let per thread reader handle lead exit event. #317
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
Summary: When the leader process exits, the per thread readers will not be able to read data. This is by design. The readers need to detect such event and renable the reader after the leader process comes back. An enabled_ flag is added to the reader. We need a heuristic algorithm to detect when the leader exits. Currently, the algorithm is simple: if we read same value for the first hardware counter twice, the leader is most likely gone. We may need to revisit this later. A unit test is added to cover this. We also need to adjust close() function of BPerfEventsGroup to make it easier for the reader to detect leader exit events. Differential Revision: D64486001
facebook-github-bot
added
the
CLA Signed
|
This pull request was exported from Phabricator. Differential Revision: D64486001 |
|
This pull request has been merged in bc3362d. |
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Outdated suggestions cannot be applied.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.
Summary:
When the leader process exits, the per thread readers will not be able to
read data. This is by design. The readers need to detect such event and
renable the reader after the leader process comes back.
An enabled_ flag is added to the reader. We need a heuristic algorithm to
detect when the leader exits. Currently, the algorithm is simple: if we
read same value for the first hardware counter twice, the leader is most
likely gone. We may need to revisit this later.
A unit test is added to cover this. We also need to adjust close()
function of BPerfEventsGroup to make it easier for the reader to detect
leader exit events.
Differential Revision: D64486001