Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Remove sharding for VecCache #123556

Merged
merged 1 commit into from
Apr 7, 2024
Merged

Remove sharding for VecCache #123556

merged 1 commit into from
Apr 7, 2024

Conversation

Mark-Simulacrum
Copy link
Member

This sharding is never used (per the comment in code). If we re-add sharding at some point in the future this is cheap to restore, but for now no need for the extra complexity.

@Mark-Simulacrum
Remove sharding for VecCache
668b318 
This sharding is never used (per the comment in code). If we re-add
sharding at some point in the future this is cheap to restore, but for
now no need for the extra complexity.
@rustbot
Copy link
Collaborator

rustbot commented Apr 6, 2024

r? @Nadrieril

rustbot has assigned @Nadrieril.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

@rustbot rustbot added A-query-system Area: The rustc query system (https://rustc-dev-guide.rust-lang.org/query.html) S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Apr 6, 2024
@Nadrieril
Copy link
Member

@bors try @rust-timer queue

@rust-timer

This comment has been minimized.

Sign in to view
@rustbot rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Apr 6, 2024
@bors
Copy link
Contributor

bors commented Apr 6, 2024

⌛ Trying commit 668b318 with merge 2266f0b...

bors added a commit to rust-lang-ci/rust that referenced this pull request Apr 6, 2024
@bors
Auto merge of rust-lang#123556 - Mark-Simulacrum:drop-unused-sharding…
2266f0b 
…, r=<try>

Remove sharding for VecCache

This sharding is never used (per the comment in code). If we re-add sharding at some point in the future this is cheap to restore, but for now no need for the extra complexity.
Nadrieril
Nadrieril reviewed Apr 6, 2024
View reviewed changes
compiler/rustc_query_system/src/query/caches.rs
Comment on lines -125 to 124
let lock = self.cache.lock_shard_by_hash(key.index() as u64);
let lock = self.cache.lock();
if let Some(Some(value)) = lock.get(*key) { Some(*value) } else { None }
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

IndexVec is contiguous, right? Did the old implementation make much sense? From a quick glance, it seems to me that if the indices were in fact high enough to shard we'd end up with largely empty IndexVecs in each shard

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yes, that sounds plausible. In any case IIRC the sharding uses the high bits and we'd almost certainly run out of memory first.

@bors
Copy link
Contributor

bors commented Apr 6, 2024

☀️ Try build successful - checks-actions
Build commit: 2266f0b (2266f0b25da94ef800559d741b4aad9e7cdfc889)

@rust-timer

This comment has been minimized.

Sign in to view
@rust-timer
Copy link
Collaborator

Finished benchmarking commit (2266f0b): comparison URL.

Overall result: ❌✅ regressions and improvements - ACTION NEEDED

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

mean range count
Regressions ❌
(primary)		 - - 0
Regressions ❌
(secondary)		 0.5% [0.4%, 1.0%] 7
Improvements ✅
(primary)		 - - 0
Improvements ✅
(secondary)		 -0.9% [-1.0%, -0.7%] 4
All ❌✅ (primary) - - 0

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

mean range count
Regressions ❌
(primary)		 0.7% [0.7%, 0.7%] 1
Regressions ❌
(secondary)		 - - 0
Improvements ✅
(primary)		 -5.1% [-5.1%, -5.1%] 1
Improvements ✅
(secondary)		 - - 0
All ❌✅ (primary) -2.2% [-5.1%, 0.7%] 2

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

mean range count
Regressions ❌
(primary)		 - - 0
Regressions ❌
(secondary)		 - - 0
Improvements ✅
(primary)		 - - 0
Improvements ✅
(secondary)		 -2.2% [-2.2%, -2.2%] 1
All ❌✅ (primary) - - 0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 666.761s -> 667.971s (0.18%)
Artifact size: 318.27 MiB -> 318.14 MiB (-0.04%)

@rustbot rustbot added perf-regression Performance regression. and removed S-waiting-on-perf Status: Waiting on a perf run to be completed. labels Apr 6, 2024
@Nadrieril
Copy link
Member

Looks good!

@bors r+

@bors
Copy link
Contributor

bors commented Apr 6, 2024

📌 Commit 668b318 has been approved by Nadrieril

It is now in the queue for this repository.

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Apr 6, 2024
@Mark-Simulacrum Mark-Simulacrum added the perf-regression-triaged The performance regression has been triaged. label Apr 6, 2024
@bors
Copy link
Contributor

bors commented Apr 7, 2024

⌛ Testing commit 668b318 with merge af25253...

@bors
Copy link
Contributor

bors commented Apr 7, 2024

☀️ Test successful - checks-actions
Approved by: Nadrieril
Pushing af25253 to master...

@bors bors added the merged-by-bors This PR was explicitly merged by bors. label Apr 7, 2024
@bors bors merged commit af25253 into rust-lang:master Apr 7, 2024
12 checks passed
@rustbot rustbot added this to the 1.79.0 milestone Apr 7, 2024
@rust-timer
Copy link
Collaborator

Finished benchmarking commit (af25253): comparison URL.

Overall result: ❌✅ regressions and improvements - ACTION NEEDED

Next Steps: If you can justify the regressions found in this perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please open an issue or create a new PR that fixes the regressions, add a comment linking to the newly created issue or PR, and then add the perf-regression-triaged label to this PR.

@rustbot label: +perf-regression
cc @rust-lang/wg-compiler-performance

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

mean range count
Regressions ❌
(primary)		 0.4% [0.4%, 0.4%] 1
Regressions ❌
(secondary)		 0.5% [0.2%, 1.0%] 5
Improvements ✅
(primary)		 - - 0
Improvements ✅
(secondary)		 -0.9% [-1.1%, -0.7%] 4
All ❌✅ (primary) 0.4% [0.4%, 0.4%] 1

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

mean range count
Regressions ❌
(primary)		 - - 0
Regressions ❌
(secondary)		 - - 0
Improvements ✅
(primary)		 -4.7% [-5.7%, -3.7%] 2
Improvements ✅
(secondary)		 - - 0
All ❌✅ (primary) -4.7% [-5.7%, -3.7%] 2

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 668.846s -> 668.633s (-0.03%)
Artifact size: 318.48 MiB -> 318.20 MiB (-0.09%)

@Mark-Simulacrum Mark-Simulacrum deleted the drop-unused-sharding branch April 11, 2024 15:01
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Reviewers

@Nadrieril Nadrieril Nadrieril left review comments

Assignees

@Nadrieril Nadrieril

Labels
A-query-system Area: The rustc query system (https://rustc-dev-guide.rust-lang.org/query.html) merged-by-bors This PR was explicitly merged by bors. perf-regression Performance regression. perf-regression-triaged The performance regression has been triaged. S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.
Projects
None yet
Milestone
1.79.0
Development

Successfully merging this pull request may close these issues.

None yet
5 participants
@Mark-Simulacrum @rustbot @Nadrieril @rust-timer @bors