xfsslower: Fix compilation error due to rewriter update #1767
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
|
I'm concerned that we have other tools with the same issue. Any thoughts on this:
|
|
@bobrik I'm answering in the original issue. Give me a minute to track the appropriate commits I need to reference. Could you double check that this does fix the issue for you too in the meantime? |
bobrik
reviewed
May 17, 2018
tools/xfsslower.py
Outdated
| bpf_probe_read(&de, sizeof(de), &valp->fp->f_path.dentry); | ||
| bpf_probe_read(&qs, sizeof(qs), (void *)&de->d_name); | ||
| struct dentry *de = valp->fp->f_path.dentry; | ||
| struct qstr qs = de->d_name; |
There was a problem hiding this comment.
You can do just this:
struct qstr qs = valp->fp->f_path.dentry->d_name;
There was a problem hiding this comment.
Oh, yes. Looks like we can :-)
That addresses the above comment too. Thanks!
bobrik
approved these changes
May 17, 2018
Since ad2d0d9, the bcc rewriter is able to track more external pointers going through maps. xfsslower and zfsslower were relying on the rewriter not being able to replace some dereferences. This commit takes this into account and removes two unnecessary calls to bpf_probe_read.
|
Looks like zfsslower has the exact same issue (could have guessed :/). Other tools look fine. I'll try to improve the smoke_tool tests to catch this kind of issues tomorrow. |
bobrik
approved these changes
May 17, 2018
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Outdated suggestions cannot be applied.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.
Since #1737, the bcc rewriter is able to track more external pointers going through maps. xfsslower was relying on the rewriter not being able to replace some dereferences. This commit takes this
into account and removes two unnecessary calls to
bpf_probe_read.Fixes #1766.
/cc @bobrik