fix(disksnoop): register to blk_mq_complete_request #5118
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saiintbrisson
requested review from
brendangregg,
goldshtn,
davemarchevsky,
drzaeus77,
yonghong-song and
4ast
as code owners
| 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") |
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Why the above change?
| 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") |
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Let us just use tracepoint block:block_rq_complete here. It is more stable.
|
for
Let us just use tracepoint. It should be fine. It would be good that example can represent reasonable recent kernel internals. |
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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.