Remove ackable_work; ack immediately instead
#1552
Merged
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
leftwo
approved these changes
Nov 6, 2024
mkeeter
force-pushed
the
mkeeter/immediate-ack
branch
2 times, most recently
from
25abe34 to
3329865
Compare
mkeeter
force-pushed
the
mkeeter/immediate-ack
branch
from
3329865 to
2005e76
Compare
jmpesp
approved these changes
Nov 15, 2024
mkeeter
force-pushed
the
mkeeter/immediate-ack
branch
from
4b0a34e to
a33bee3
Compare
mkeeter
added a commit
that referenced
this pull request
Nov 18, 2024
There are a bunch of places where we check to see if jobs should be acked and/or retired: - `Downstairs::enqueue` (if skipped on all three Downstairs) - `Downstairs::skip_all_jobs` (for skipped jobs only) - `DownstairsClient::process_io_completion` (lots of conditionals to decide if we're ready to ack; returns a flag to `Downstairs::process_io_completion_inner`) This PR consolidates ack and retire checks into a single place: `Downstairs::ack_check`. This new function is responsible for deciding when to ack and retire jobs; it's called in all of the places where you'd expect. `DownstairsClient::process_io_completion` is reorganized, with one minor logical change: non-fatal read errors now increment the `downstairs_errors` counter. It's no longer responsible for deciding when to ack a job; that's now in `Downstairs::ack_check`. The `up-to-ds-*-done` DTrace probes are removed, because (after #1552) they fire immediately before the equivalent `gw-*-done` probes; there's no delay waiting for ackable jobs to be acked.
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Outdated suggestions cannot be applied.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.
A long time ago, one task accumulated ackable jobs into
Downstairs::ackable_workand a different task periodically read out that set and sent acks back to the guest.The tasks have long since been consolidated, but the
ackable_workset remained.This PR removes the
ackable_workset, acking jobs immediately when they are ready. It's a significant LOC simplification, because it's removing intermediate state (which previously had to be checked in unit tests).There's one subtlety in handling live-repair: previously, the live-repair check would look in
ackable_workto see if the next job was ackable, which indicates that live-repair can continue. Now, we update theLiveRepairStatedirectly inDownstairs::ack, storing a result for the pending live-repair job.