fix(disksnoop): register to blk_mq_complete_request #5118
Conversation
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
saiintbrisson
requested review from
4ast,
brendangregg,
davemarchevsky,
drzaeus77,
goldshtn and
yonghong-song
as code owners
| b.attach_kprobe(event="blk_start_request", fn_name="trace_start") | ||
| b.attach_kprobe(event="blk_mq_start_request", fn_name="trace_start") | ||
| if BPF.get_kprobe_functions(b'blk_start_request'): | ||
| b.attach_kprobe(event="blk_start_request", fn_name="trace_start") |
Collaborator
There was a problem hiding this comment.
Why the above change?
| elif BPF.get_kprobe_functions(b'blk_account_io_done'): | ||
| b.attach_kprobe(event="blk_account_io_done", fn_name="trace_completion") | ||
| elif BPF.get_kprobe_functions(b'blk_mq_complete_request'): | ||
| b.attach_kprobe(event="blk_mq_complete_request", fn_name="trace_completion") |
Collaborator
There was a problem hiding this comment.
Let us just use tracepoint block:block_rq_complete here. It is more stable.
Collaborator
|
for
Let us just use tracepoint. It should be fine. It would be good that example can represent reasonable recent kernel internals. |
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Outdated suggestions cannot be applied.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.
As mentioned in #4691,
disksnoop, likebiosnoop, rely on functions that can be inlined, likeblk_account_io_done. This change adds a new functionblk_mq_complete_requestas a fallback in case that the others were inlined. I haven't changed this to support tracepoint because the tutorial guide would have to be considerably rearranged to make it follow a logical order, as the first mention of tracepoint is on lesson 12.