From nobody Tue Dec 16 14:06:29 2025 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 C9B6A27510B; Mon, 5 May 2025 21:22:29 +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=1746480149; cv=none; b=lKOSHQbpBmF9BSzr+BdwDqN281WGl8szNhWqzDEnPnCeCNI364xMqioJZxVq6O8pl750QPXZj1AO8K6EYpuyb2xgreQLriqQNvBDgg9r3jhsmQU9NAOqL6yd9+xdQfSP8CPEC8pAAbFNczxoC36MjFKQyUALScO2lpI+RM741wc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746480149; c=relaxed/simple; bh=3SGqRucYvzm4r1ZRppD5xh4448hzq4HUOiq6525cB54=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=B3YYkLUNy9aRxMpTlDZUNjEJt9bsadMRXrxRaMloYkxaRXvAoS8Bg+WLDrmjrfQ4Sm1YMhLtqGvgfxCpV3kFflMhcjUPfyhdu4Z47YKdYLyS/Ucp5YGPLBSA+ZRiHfCje0CLRlSFtJfmW/w5rj4yAp7ei3pSgRqR6++ws1rP25w= 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 4FFD8C4CEF1; Mon, 5 May 2025 21:22:29 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uC3Gm-00000000yFE-0r8E; Mon, 05 May 2025 17:22:36 -0400 Message-ID: <20250505212236.059853898@goodmis.org> User-Agent: quilt/0.68 Date: Mon, 05 May 2025 17:21:13 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton Subject: [PATCH v2 09/13] ring-buffer: Add ring_buffer_record_is_on_cpu() References: <20250505212104.986494754@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Steven Rostedt Add the function ring_buffer_record_is_on_cpu() that returns true if the ring buffer for a give CPU is writable and false otherwise. Also add tracer_tracing_is_on_cpu() to return if the ring buffer for a given CPU is writeable for a given trace_array. Signed-off-by: Steven Rostedt (Google) --- include/linux/ring_buffer.h | 1 + kernel/trace/ring_buffer.c | 18 ++++++++++++++++++ kernel/trace/trace.h | 15 +++++++++++++++ 3 files changed, 34 insertions(+) diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index 56e27263acf8..cd7f0ae26615 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -192,6 +192,7 @@ void ring_buffer_record_off(struct trace_buffer *buffer= ); void ring_buffer_record_on(struct trace_buffer *buffer); bool ring_buffer_record_is_on(struct trace_buffer *buffer); bool ring_buffer_record_is_set_on(struct trace_buffer *buffer); +bool ring_buffer_record_is_on_cpu(struct trace_buffer *buffer, int cpu); void ring_buffer_record_disable_cpu(struct trace_buffer *buffer, int cpu); void ring_buffer_record_enable_cpu(struct trace_buffer *buffer, int cpu); =20 diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index c0f877d39a24..1ca482955dae 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -4882,6 +4882,24 @@ bool ring_buffer_record_is_set_on(struct trace_buffe= r *buffer) return !(atomic_read(&buffer->record_disabled) & RB_BUFFER_OFF); } =20 +/** + * ring_buffer_record_is_on_cpu - return true if the ring buffer can write + * @buffer: The ring buffer to see if write is enabled + * @cpu: The CPU to test if the ring buffer can write too + * + * Returns true if the ring buffer is in a state that it accepts writes + * for a particular CPU. + */ +bool ring_buffer_record_is_on_cpu(struct trace_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + cpu_buffer =3D buffer->buffers[cpu]; + + return ring_buffer_record_is_set_on(buffer) && + !atomic_read(&cpu_buffer->record_disabled); +} + /** * ring_buffer_record_disable_cpu - stop all writes into the cpu_buffer * @buffer: The ring buffer to stop writes to. diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 74f1fe5788d4..69c1ecfb2290 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -673,6 +673,21 @@ struct dentry *trace_create_file(const char *name, void *data, const struct file_operations *fops); =20 + +/** + * tracer_tracing_is_on_cpu - show real state of ring buffer enabled on fo= r a cpu + * @tr : the trace array to know if ring buffer is enabled + * @cpu: The cpu buffer to check if enabled + * + * Shows real state of the per CPU buffer if it is enabled or not. + */ +static inline bool tracer_tracing_is_on_cpu(struct trace_array *tr, int cp= u) +{ + if (tr->array_buffer.buffer) + return ring_buffer_record_is_on_cpu(tr->array_buffer.buffer, cpu); + return false; +} + int tracing_init_dentry(void); =20 struct ring_buffer_event; --=20 2.47.2