From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2E7362253F0 for ; Fri, 24 Jan 2025 18:48:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737744527; cv=none; b=V5QZybiHwg/nCtsWKW6ylsVy1bDE/Iix0KwAkObsOdAXouYWSXZcU4CcPsBuL5V3/rsBhVep0eV4/KBk7GABz+uenjbhaLRrdr4zcEqdGo6v9Y57G3T87G9uLBdZLTMPubKY9iQYzFozSTpPkB8LERZzRn8r3cSs3YqFHnNi6xI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737744527; c=relaxed/simple; bh=Qoh8kZsK0gfvB6VLSuOCtYL1/6voSOS2wQ8Xee5J7H0=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=aeuOOz7d7+6dPOGJb+YQd48iiXkVCW5uJJLVRx3TgoKzCcapfRPw6kKfob91TF5wEfiNBcXULjOT0b26znJXkqauyxkgQuxoYvqr8V8MykJmLtEB6Hocs7fUPdwmcKqM7vb8mIMJgeVsBt2aG+zAMkEGSeZpWmjRfwjZaBUA0pg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 180BDC4CEE6; Fri, 24 Jan 2025 18:48:47 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98) (envelope-from ) id 1tbOji-00000001FE9-0ueG; Fri, 24 Jan 2025 13:48:58 -0500 Message-ID: <20250124184858.068142598@goodmis.org> User-Agent: quilt/0.68 Date: Fri, 24 Jan 2025 13:48:46 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Tomas Glozar , John Kacur , Luis Goncalves , Gabriele Monaco Subject: [for-next][PATCH 11/14] rtla: Count missed trace events References: <20250124184835.052017152@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: Tomas Glozar Add function collect_missed_events to trace.c to act as a callback for tracefs_follow_missed_events, summing the number of total missed events into a new field missing_events of struct trace_instance. In case record->missed_events is negative, trace->missed_events is set to UINT64_MAX to signify an unknown number of events was missed. The callback is activated on initialization of the trace instance. Cc: John Kacur Cc: Luis Goncalves Cc: Gabriele Monaco Link: https://lore.kernel.org/20250123142339.990300-2-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google) --- tools/tracing/rtla/src/trace.c | 34 ++++++++++++++++++++++++++++++++++ tools/tracing/rtla/src/trace.h | 1 + 2 files changed, 35 insertions(+) diff --git a/tools/tracing/rtla/src/trace.c b/tools/tracing/rtla/src/trace.c index 80b14b8a3c2e..94e490782f14 100644 --- a/tools/tracing/rtla/src/trace.c +++ b/tools/tracing/rtla/src/trace.c @@ -126,6 +126,31 @@ collect_registered_events(struct tep_event *event, struct tep_record *record, return 0; } +/* + * collect_missed_events - record number of missed events + * + * If rtla cannot keep up with events generated by tracer, events are going + * to fall out of the ring buffer. + * Collect how many events were missed so it can be reported to the user. + */ +static int +collect_missed_events(struct tep_event *event, struct tep_record *record, + int cpu, void *context) +{ + struct trace_instance *trace = context; + + if (trace->missed_events == UINT64_MAX) + return 0; + + if (record->missed_events > 0) + trace->missed_events += record->missed_events; + else + /* Events missed but no data on how many */ + trace->missed_events = UINT64_MAX; + + return 0; +} + /* * trace_instance_destroy - destroy and free a rtla trace instance */ @@ -181,6 +206,15 @@ int trace_instance_init(struct trace_instance *trace, char *tool_name) */ tracefs_trace_off(trace->inst); + /* + * Collect the number of events missed due to tracefs buffer + * overflow. + */ + trace->missed_events = 0; + tracefs_follow_missed_events(trace->inst, + collect_missed_events, + trace); + return 0; out_err: diff --git a/tools/tracing/rtla/src/trace.h b/tools/tracing/rtla/src/trace.h index c3e03f7df770..a6e88709604b 100644 --- a/tools/tracing/rtla/src/trace.h +++ b/tools/tracing/rtla/src/trace.h @@ -17,6 +17,7 @@ struct trace_instance { struct tracefs_instance *inst; struct tep_handle *tep; struct trace_seq *seq; + unsigned long long missed_events; }; int trace_instance_init(struct trace_instance *trace, char *tool_name); -- 2.45.2