Skip to content

planner: LRUPlanCache memory trace#38069

Merged
ti-chi-bot merged 43 commits intopingcap:masterfrom
fzzf678:planCacheValue_memTrace
Oct 21, 2022
Merged

planner: LRUPlanCache memory trace#38069
ti-chi-bot merged 43 commits intopingcap:masterfrom
fzzf678:planCacheValue_memTrace

Conversation

@fzzf678
Copy link
Contributor

@fzzf678 fzzf678 commented Sep 22, 2022

What problem does this PR solve?

Issue Number: ref #37632

Problem Summary:
Count the memory usage of LRUPlanCache

What is changed and how it works?

Implement MemoryUsage() for

  • planCacheKey
  • PlanCacheValue
  • LRUPlanCache

Check List

Tests

  • Unit test
  • Integration test
  • Manual test (add detailed scripts or steps below)
  • No code

Side effects

  • Performance regression: Consumes more CPU
  • Performance regression: Consumes more Memory
  • Breaking backward compatibility

Documentation

  • Affects user behaviors
  • Contains syntax changes
  • Contains variable changes
  • Contains experimental features
  • Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

@ti-chi-bot
Copy link
Member

ti-chi-bot commented Sep 22, 2022

[REVIEW NOTIFICATION]

This pull request has been approved by:

  • Reminiscent
  • qw4990

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

The full list of commands accepted by this bot can be found here.

Details

Reviewer can indicate their review by submitting an approval review.
Reviewer can cancel approval by submitting a request changes review.

@ti-chi-bot ti-chi-bot added release-note-none Denotes a PR that doesn't merit a release note. size/M Denotes a PR that changes 30-99 lines, ignoring generated files. labels Sep 22, 2022
@fzzf678 fzzf678 marked this pull request as draft September 22, 2022 00:59
@ti-chi-bot ti-chi-bot added the do-not-merge/work-in-progress Indicates that a PR should not merge because it is a work in progress. label Sep 22, 2022
@fzzf678 fzzf678 marked this pull request as ready for review September 28, 2022 09:09
@ti-chi-bot ti-chi-bot removed the do-not-merge/work-in-progress Indicates that a PR should not merge because it is a work in progress. label Sep 28, 2022
const emptyLRUPlanCacheSize = int64(unsafe.Sizeof(LRUPlanCache{}))

// MemoryUsage return the memory usage of LRUPlanCache
func (l *LRUPlanCache) MemoryUsage() (sum int64) {
Copy link
Contributor

Choose a reason for hiding this comment

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

It seems like we should maintain its memory usage dynamically in l.Put.

@ti-chi-bot ti-chi-bot added size/L Denotes a PR that changes 100-499 lines, ignoring generated files. and removed size/M Denotes a PR that changes 30-99 lines, ignoring generated files. labels Oct 11, 2022
@ti-chi-bot ti-chi-bot added the status/LGT1 Indicates that a PR has LGTM 1. label Oct 19, 2022

// unKnownMemoryUsage represent the memory usage of uncounted structure, maybe need implement later
// 7 has no special meaning
const unKnownMemoryUsage = 7
Copy link
Contributor

Choose a reason for hiding this comment

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

Seems too small. Actually, I have tested it before and got an empirical value 100KB, you can see it in our doc https://docs.pingcap.com/tidb/dev/sql-prepared-plan-cache#memory-management-of-prepared-plan-cache

// todo: pass label when track general plan cache memory
func newTrackerForLRUPC() *memory.Tracker {
m := memory.NewTracker(memory.LabelForPreparedPlanCache, -1)
m.Consume(emptyLRUPlanCacheSize)
Copy link
Contributor

Choose a reason for hiding this comment

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

How about ignoring this part of memory usage?

Comment on lines +252 to +259
func elementMemoryUsage(e *list.Element) (sum int64) {
pVal, ok1 := e.Value.(*planCacheEntry).PlanValue.(*PlanCacheValue)
pKey, ok2 := e.Value.(*planCacheEntry).PlanValue.(*planCacheKey)
if !ok1 || !ok2 {
return
}
return pKey.MemoryUsage() + pVal.MemoryUsage()
}
Copy link
Contributor

Choose a reason for hiding this comment

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

Please implement this function as planCacheEntry.MemoryUsage

@fzzf678
Copy link
Contributor Author

fzzf678 commented Oct 20, 2022

/run-build

v := &PlanCacheValue{Plan: p}
lru.Put(k, v, pTypes)
res += k.MemoryUsage() + v.MemoryUsage()
fmt.Println(lru.MemoryUsage(), res)
Copy link
Contributor

Choose a reason for hiding this comment

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

Should remove this line.

@ti-chi-bot ti-chi-bot added size/XL Denotes a PR that changes 500-999 lines, ignoring generated files. and removed size/L Denotes a PR that changes 100-499 lines, ignoring generated files. labels Oct 21, 2022
@ti-chi-bot ti-chi-bot added status/LGT2 Indicates that a PR has LGTM 2. and removed status/LGT1 Indicates that a PR has LGTM 1. labels Oct 21, 2022
@qw4990
Copy link
Contributor

qw4990 commented Oct 21, 2022

/merge

@ti-chi-bot
Copy link
Member

This pull request has been accepted and is ready to merge.

DetailsCommit hash: 0445583

@ti-chi-bot ti-chi-bot added the status/can-merge Indicates a PR has been approved by a committer. label Oct 21, 2022
@ti-chi-bot
Copy link
Member

@fzzf678: Your PR was out of date, I have automatically updated it for you.

At the same time I will also trigger all tests for you:

/run-all-tests

If the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

@ti-chi-bot ti-chi-bot merged commit f65f4ba into pingcap:master Oct 21, 2022
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

epic/plan-cache release-note-none Denotes a PR that doesn't merit a release note. sig/planner SIG: Planner size/XL Denotes a PR that changes 500-999 lines, ignoring generated files. status/can-merge Indicates a PR has been approved by a committer. status/LGT2 Indicates that a PR has LGTM 2.

Projects

None yet

Development

Successfully merging this pull request may close these issues.

4 participants