From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: [PATCH v2 08/13] tracing: Do not use per CPU array_buffer.data->disabled for cpumask
Date: Mon, 05 May 2025 17:21:12 -0400 [thread overview]
Message-ID: <20250505212235.885452497@goodmis.org> (raw)
In-Reply-To: <20250505212104.986494754@goodmis.org>
From: Steven Rostedt <rostedt@goodmis.org>
The per CPU "disabled" value was the original way to disable tracing when
the tracing subsystem was first created. Today, the ring buffer
infrastructure has its own way to disable tracing. In fact, things have
changed so much since 2008 that many things ignore the disable flag.
Do not bother setting the per CPU disabled flag of the array_buffer data
to use to determine what CPUs can write to the buffer and only rely on the
ring buffer code itself to disabled it.
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/trace.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 490c24271a3d..395d1229da77 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5081,7 +5081,6 @@ int tracing_set_cpumask(struct trace_array *tr,
*/
if (cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
!cpumask_test_cpu(cpu, tracing_cpumask_new)) {
- atomic_inc(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled);
ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu);
#ifdef CONFIG_TRACER_MAX_TRACE
ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu);
@@ -5089,7 +5088,6 @@ int tracing_set_cpumask(struct trace_array *tr,
}
if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
cpumask_test_cpu(cpu, tracing_cpumask_new)) {
- atomic_dec(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled);
ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu);
#ifdef CONFIG_TRACER_MAX_TRACE
ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu);
--
2.47.2
next prev parent reply other threads:[~2025-05-05 21:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-05 21:21 [PATCH v2 00/13] tracing: Remove most uses of "disabled" field Steven Rostedt
2025-05-05 21:21 ` [PATCH v2 01/13] tracing/mmiotrace: Remove reference to unused per CPU data pointer Steven Rostedt
2025-05-05 21:21 ` [PATCH v2 02/13] ftrace: Do not bother checking per CPU "disabled" flag Steven Rostedt
2025-05-05 21:21 ` [PATCH v2 03/13] tracing: Just use this_cpu_read() to access ignore_pid Steven Rostedt
2025-05-05 21:21 ` [PATCH v2 04/13] tracing: Add tracer_tracing_disable/enable() functions Steven Rostedt
2025-05-05 21:21 ` [PATCH v2 05/13] tracing: Use tracer_tracing_disable() instead of "disabled" field for ftrace_dump_one() Steven Rostedt
2025-05-05 21:21 ` [PATCH v2 06/13] tracing: kdb: Use tracer_tracing_on/off() instead of setting per CPU disabled Steven Rostedt
2025-05-05 21:21 ` [PATCH v2 07/13] ftrace: Do not disabled function graph based on "disabled" field Steven Rostedt
2025-05-05 21:21 ` Steven Rostedt [this message]
2025-05-05 21:21 ` [PATCH v2 09/13] ring-buffer: Add ring_buffer_record_is_on_cpu() Steven Rostedt
2025-05-05 21:21 ` [PATCH v2 10/13] tracing: branch: Use trace_tracing_is_on_cpu() instead of "disabled" field Steven Rostedt
2025-05-05 21:21 ` [PATCH v2 11/13] tracing: Convert the per CPU "disabled" counter to local from atomic Steven Rostedt
2025-05-05 21:21 ` [PATCH v2 12/13] tracing: Use atomic_inc_return() for updating "disabled" counter in irqsoff tracer Steven Rostedt
2025-05-05 21:21 ` [PATCH v2 13/13] tracing: Remove unused buffer_page field from trace_array_cpu structure Steven Rostedt
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