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charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.1 (3.56.1-1.fc42) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Wed, 2025-04-23 at 08:50 +0200, Nam Cao wrote: > Add a monitor for checking that real-time tasks do not go to sleep in > a > manner that may cause undesirable latency. >=20 > Also change > RV depends on TRACING > to > RV select TRACING > to avoid the following recursive dependency: >=20 > =C2=A0error: recursive dependency detected! > symbol TRACING is selected by PREEMPTIRQ_TRACEPOINTS > symbol PREEMPTIRQ_TRACEPOINTS depends on TRACE_IRQFLAGS > symbol TRACE_IRQFLAGS is selected by RV_MON_SLEEP > symbol RV_MON_SLEEP depends on RV > symbol RV depends on TRACING >=20 > Signed-off-by: Nam Cao > --- >=20 I've been playing with these monitors, code-wise they look good. I tested a bit and they seem to work without many surprises by doing something as simple as: perf stat -e rv:error_sleep stress-ng --cpu-sched 1 -t 10s -- shows several errors -- perf stat -e rv:error_sleep stress-ng --prio-inv 1 --prio-inv-policy rr -- shows only 1 error (normal while starting the program?) -- Not quite sound, but does it look a reasonable test to you? I quickly tried the same with the other monitor comparing the number of errors with the page_faults generated by perf, but that didn't make too much sense. Perhaps I'm doing something wrong here though (the number reported by perf for page faults feels a bit too high). perf stat -e page-faults -e rv:error_pagefault stress-ng --cyclic 1 Anyway, the monitor looks good to me Reviewed-by: Gabriele Monaco but it'd be nice if you have tips to share how to quickly test it (e.g. without writing a custom workload). Thanks, Gabriele