On Tue, 22 Sep 2026 04:41:53 +0000 [email protected] wrote: > Thank you for your contribution! Sashiko AI review found 2 potential issue(s) > to consider: > - [Low] kselftest: trace buffer not cleared before verifying offline wprobe > triggers > - [Low] kselftest: missing set_wprobe dependency check in requires lines > -- > > commit 0d531760cdf15ae449a5bc0545ea39a43134b990 > Author: Masami Hiramatsu (Google) <[email protected]> > > selftests: tracing: Add wprobe trigger testcases > > This commit adds several test scripts for wprobe triggers in the ftrace > selftests. The test scripts verify setting and clearing wprobe triggers, > CPU hotplug behavior for wprobes, and syntax error logging. > > Link: > https://lore.kernel.org/all/59637b96946653393a7ad3c7de094094796b39c2.1785067572.git.wangjinchao...@gmail.com/ > > > diff --git > > a/tools/testing/selftests/ftrace/test.d/trigger/trigger-wprobe-hotplug.tc > > b/tools/testing/selftests/ftrace/test.d/trigger/trigger-wprobe-hotplug.tc > > --- /dev/null > > +++ > > b/tools/testing/selftests/ftrace/test.d/trigger/trigger-wprobe-hotplug.tc > > @@ -0,0 +1,150 @@ > > +#!/bin/sh > > +# SPDX-License-Identifier: GPL-2.0 > > +# description: event trigger - test wprobe trigger across cpu hotplug > > +# requires: dynamic_events "w[:[<group>/][<event>]] > > [r|w|rw]@<addr>[:<len>]":README "f[:[<group>/][<event>]] > > <func-name>[%return] [<args>]":README > > events/sched/sched_process_fork/trigger > > "[(structname[,field])]<argname>[->field[->field|.field...]]":README > > [Severity: Low] > Should we check for set_wprobe in the README in this requires line? If a > kernel > has CONFIG_WPROBE_EVENTS=y but CONFIG_WPROBE_TRIGGERS=n, it seems this test > will execute and fail unexpectedly with "Failed to set set_wprobe trigger" > instead of being gracefully skipped as UNRESOLVED.
Ah, good catch! OK, let me add that in the requires line. > > [ ... ] > > > +:;: "Take target CPU offline" ;: > > +echo 0 > $cpu/online > > +sleep 1 > > + > > +# Wait for sample_timer_cb to fire and set_wprobe trigger to activate > > while CPU is offline > > +sleep 2 > > + > > +:;: "Check set_wprobe trigger activated the watchpoint" ;: > > +if ! grep -q watch trace; then > > + fail "Failed to trigger watchpoint while CPU is offline" > > +fi > > [Severity: Low] > Does this grep falsely match events generated while the CPU was still online? > Because the target fprobe (sample_timer_cb) fires continuously, the trace > buffer could log a watch event before the offlining process actually > completes. > Should we add a clear_trace call either before or right after taking the CPU > offline? OK, let me add it. Thanks! -- Masami Hiramatsu (Google) <[email protected]>
