From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4F3E2449B11 for ; Mon, 7 Sep 2026 09:43:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788774184; cv=none; b=ZZooIqiYfqclrXQ267NidJSdT8woj1lWqYF/M/dbaZYs8Uwn0wR8YF6PaaA12VklUwnL+IPI80q7tPiq/Q8jx+ul/JyNpKqKO3mgqVtKH1lrcM2ixW57S2gy6A48d4c3gYS1uB3V7ZBJHkvougnAOjtKx3gsqrQNkCwTN8Zhy2U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788774184; c=relaxed/simple; bh=uDq11k/rXkHA+TsuM739e/4WFoKrhhA393kZJdFyy3c=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=TjTpcvkcA2dLaz5IlCILint4PivpvRm2uWSjpr9lLxDxbo4avkrtFhpTthEbSfMCVBH0dmfVuYdl0Y7PCZwfJjByKD6GloA3K+U029oMk8pWzvafYUOw8Y7BPCjrLPu0d62h6hvT3Z6xyHxp5uwfxcvdoaQBOE6AGqGFjJq8WPI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=fQXeqzh1; arc=none smtp.client-ip=209.85.128.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="fQXeqzh1" Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-49b7c1dcc82so19672985e9.0 for ; Mon, 07 Sep 2026 02:43:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1788774180; x=1789378980; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:mime-version:date:from :to:cc:subject:date:message-id:reply-to:content-type; bh=9lZ6K3arAX2g5RNC4qtLfEijgSqmPC4MVV8qXWFmH9w=; b=fQXeqzh1Co9BTpkqWbBfJvT4iDpZuU0G2JVB0wRFNzjs0S0UTGaxiNsUXbn7vKqkIY EVR9/gRlB8tsJwAF/hvyUYBP2uJXde1+ZZNTc4JMp+uJlz0JSTeU3PZg59a7iJZkf1G4 BujJLSVGZ5L+JYSUdCSYqcKtPxRtVkpUPbbxItVF1+pUltQR7VtGya3Q+7/Ya7qtuj9r FZc0JrxpvsKcd4ukn/RhtRbnqI79aNHCbr1aB6RsOOuQiL+jFEouH2iBoAV4sHaY80tM sIsl2feXKrgWuPrNskbMNpQDnCPhyowd9I0JPk70ULa/SpNYAr50jbMku/Y8ENFUAFQq Rvtg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788774180; x=1789378980; h=content-type:cc:to:from:subject:message-id:mime-version:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=9lZ6K3arAX2g5RNC4qtLfEijgSqmPC4MVV8qXWFmH9w=; b=oHWK4jxsX3FI8T2OptsuTo6psNSuKkxYV6qtoGR18ouVQN88X/apucNTDmKvxD7kS0 q1xDdCVtOmTLnaK3DqYzqslpXrjRpKck1L98Y4fRZN23yDCLZxwW7D6E94FqNWNYVKWU /vStPc4jhFIZKkl3MtOgH/FlhXvjZsDvo1xRQS/LiCnoD8+AmfPoLWiTdNLL4FLKqKqQ TGWykMTtbQHrTqec5C4JT/8PpwGmKOH/1X2KozrTV1Lr3ZTbYGcFCnaYSvwiVYgAHvoH YaBu1m3XstpZkzddoNsGx6y68jp1FKu1p19/mnIcLOHRwTJ6XKVi5f9bvg25m8G/UQZt tkuw== X-Forwarded-Encrypted: i=1; AKwUvByOMzeAkWsuagrLuTivFFXQq+RPBwnhmjxhT2Q0WUpHoKi90OO1YkgMl1np+Sgl+ekVSM68UJAY6QdVPZBuFKIARtU=@vger.kernel.org X-Gm-Message-State: AFuF++npyRUsE0nV3y49V1SyqdjxFXPYnV5GF6cvk1pJxOcqAykfXLdL ZULwW9drnvXWruV6YGYIhFliAi/8b/2IQQ0MMtznG02TBmSfxyWVkLhpWSi3Jzz2sm08fVmwqFh bIbvALBb+9+u5EJS39+NmKA== X-Received: from wmfq3.prod.google.com ([2002:a05:600c:2e43:b0:49d:fcd:8a44]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:8711:b0:49c:fc6e:a3dd with SMTP id 5b1f17b1804b1-49cfc6ea7bfmr219193155e9.28.1788774180154; Mon, 07 Sep 2026 02:43:00 -0700 (PDT) Date: Mon, 7 Sep 2026 10:42:38 +0100 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.55.0.979.g7e5102b832-goog Message-ID: <20260907094238.3624013-1-vdonnefort@google.com> Subject: [PATCH v1] ring-buffer: Rename ring_buffer_size() to ring_buffer_capacity() From: Vincent Donnefort To: rostedt@goodmis.org, mhiramat@kernel.org, linux-trace-kernel@vger.kernel.org Cc: mathieu.desnoyers@efficios.com, kernel-team@android.com, linux-kernel@vger.kernel.org, Vincent Donnefort Content-Type: text/plain; charset="UTF-8" Since commit 8a5f63637890 ("ring-buffer: Fix subbuf resize race with ring buffer readers"), "capacity" refers to the memory available for events (excluding subbuffer headers) while "size" refers to the raw allocation. ring_buffer_size() actually calculates this event capacity. Rename it to ring_buffer_capacity() to align with this convention. Signed-off-by: Vincent Donnefort diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index afc7daa6ee7d..9e23ab66176b 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -165,7 +165,7 @@ void ring_buffer_iter_reset(struct ring_buffer_iter *iter); int ring_buffer_iter_empty(struct ring_buffer_iter *iter); bool ring_buffer_iter_dropped(struct ring_buffer_iter *iter); -unsigned long ring_buffer_size(struct trace_buffer *buffer, int cpu); +unsigned long ring_buffer_capacity(struct trace_buffer *buffer, int cpu); unsigned long ring_buffer_max_event_size(struct trace_buffer *buffer); void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu); diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 9c03a555a6ba..2940ff763354 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -6547,18 +6547,23 @@ void ring_buffer_iter_advance(struct ring_buffer_iter *iter) EXPORT_SYMBOL_GPL(ring_buffer_iter_advance); /** - * ring_buffer_size - return the size of the ring buffer (in bytes) + * ring_buffer_capacity - return the capacity of the ring buffer (in bytes) * @buffer: The ring buffer. - * @cpu: The CPU to get ring buffer size from. + * @cpu: The CPU to get ring buffer capacity from. + * + * Capacity is the total memory available for recording event data in the + * ring buffer. It excludes subbufer headers. + * + * Returns the capacity in bytes, or 0 if the CPU is not set in the buffer mask. */ -unsigned long ring_buffer_size(struct trace_buffer *buffer, int cpu) +unsigned long ring_buffer_capacity(struct trace_buffer *buffer, int cpu) { if (!cpumask_test_cpu(cpu, buffer->cpumask)) return 0; return rb_subbuf_capacity(buffer) * buffer->buffers[cpu]->nr_pages; } -EXPORT_SYMBOL_GPL(ring_buffer_size); +EXPORT_SYMBOL_GPL(ring_buffer_capacity); /** * ring_buffer_max_event_size - return the max data size of an event diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8658cad53cb5..f0251788ec75 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4712,9 +4712,9 @@ void trace_set_buffer_entries(struct array_buffer *buf, unsigned long val) static void update_buffer_entries(struct array_buffer *buf, int cpu) { if (cpu == RING_BUFFER_ALL_CPUS) { - trace_set_buffer_entries(buf, ring_buffer_size(buf->buffer, 0)); + trace_set_buffer_entries(buf, ring_buffer_capacity(buf->buffer, 0)); } else { - per_cpu_ptr(buf->data, cpu)->entries = ring_buffer_size(buf->buffer, cpu); + per_cpu_ptr(buf->data, cpu)->entries = ring_buffer_capacity(buf->buffer, cpu); } } @@ -8476,7 +8476,7 @@ int allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, int /* Allocate the first page for all buffers */ trace_set_buffer_entries(&tr->array_buffer, - ring_buffer_size(tr->array_buffer.buffer, 0)); + ring_buffer_capacity(tr->array_buffer.buffer, 0)); return 0; } base-commit: df2908090cda368b01ff43709f51890076c56157 -- 2.55.0.979.g7e5102b832-goog