From 88b71cd0aa39e7c97990a9e9213a360076927610 Mon Sep 17 00:00:00 2001 From: Tomas Glozar Date: Mon, 6 Oct 2025 16:31:00 +0200 Subject: [PATCH] rtla/timerlat_bpf: Stop tracing on user latency commit e4240db9336c25826a2d6634adcca86d5ee01bde upstream. rtla-timerlat allows a *thread* latency threshold to be set via the -T/--thread option. However, the timerlat tracer calls this *total* latency (stop_tracing_total_us), and stops tracing also when the return-to-user latency is over the threshold. Change the behavior of the timerlat BPF program to reflect what the timerlat tracer is doing, to avoid discrepancy between stopping collecting data in the BPF program and stopping tracing in the timerlat tracer. Cc: stable@vger.kernel.org Fixes: e34293ddcebd ("rtla/timerlat: Add BPF skeleton to collect samples") Reviewed-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20251006143100.137255-1-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Greg Kroah-Hartman --- tools/tracing/rtla/src/timerlat.bpf.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/tracing/rtla/src/timerlat.bpf.c b/tools/tracing/rtla/src/timerlat.bpf.c index 084cd10c21fc..e2265b5d6491 100644 --- a/tools/tracing/rtla/src/timerlat.bpf.c +++ b/tools/tracing/rtla/src/timerlat.bpf.c @@ -148,6 +148,9 @@ int handle_timerlat_sample(struct trace_event_raw_timerlat_sample *tp_args) } else { update_main_hist(&hist_user, bucket); update_summary(&summary_user, latency, bucket); + + if (thread_threshold != 0 && latency_us >= thread_threshold) + set_stop_tracing(); } return 0;