Always profile switches in interpreter profiler - #20342
Merged
Merged
Conversation
Before this commit, the interpreter profiler was not collecting data on switches during 'classLoadPhase'. This was done to reduce the overhead of interpreter profiler. However, we have seen cases where, for some methods compiled during 'classLoadPhase' there is no profiling data for some hot switches, making the compiler to infer the wrong block frequencies. This commit always collects information for switches. We can afford to do so because: 1. Typically switches are not that frequently executed compared to branches 2. When using the shared class cache (SCC), IProfiler is turned off during start-up, relying on profiling info stored in SCC in the cold run. Signed-off-by: Marius Pirvu <mpirvu@ca.ibm.com>
Contributor
Author
|
@dsouzai Could you please review/merge this simple PR? Thanks |
Contributor
Author
|
jenkins test sanity xlinux jdk17 |
dsouzai
approved these changes
Oct 15, 2024
Contributor
Author
|
Tests have passed |
This file contains hidden or 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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Before this commit, the interpreter profiler was not collecting data on switches during 'classLoadPhase'. This was done to reduce the overhead of interpreter profiler. However, we have seen cases where, for some methods compiled during 'classLoadPhase' there is no profiling data for some hot switches, making the compiler to infer the wrong block frequencies.
This commit always collects information for switches. We can afford to do so because: