From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f74.google.com (mail-ej1-f74.google.com [209.85.218.74]) (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 465EF15E8B for ; Fri, 3 Oct 2025 13:38:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759498741; cv=none; b=FE0fEfX7MhE868DO2eJKHWuim0ZqgjyGQqe1iprMPBQ6P/egh5gzeEsKM0/Ew7h4AFWtKp+sLwBmOKdNDivqiT8obXNijMdKFQTfM5pBp21BqD3+dPcYFA8wtNDLgIZVoyWohXMHdFO+kWjTZ7aMUaDYeyZqlXAPh+LpKNpLoZs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759498741; c=relaxed/simple; bh=jCel6UdKVBBhusHDhXdBf4Elma0H22ACWTajZaCTXDg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=aXA0+SeTjnqbEUERkKPl+C4QSOnIgvoZ2x0LMJ1vp36fT354OJVGEyh+mQoWCLPkvEOlNH4bA4UQWFynQPtNXb2AzMVLWmY4awWKcfnYFkQ1HWF3p8XdYoBDKxfI2+0eTQ9q8BaN2VNFFXJb+y3D69W7D2t2mn149q9A3ZR6ft0= 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=t/YDCCkA; arc=none smtp.client-ip=209.85.218.74 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="t/YDCCkA" Received: by mail-ej1-f74.google.com with SMTP id a640c23a62f3a-b3cd833e7b5so299917366b.3 for ; Fri, 03 Oct 2025 06:38:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1759498737; x=1760103537; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=5yvbWhTiB0g5MKRQJDvE9eSL8LzKl9DcqfgxeSAHNnQ=; b=t/YDCCkAt6bBKBq2apsZePUb82LPhp2j6GYjExpfWlG3jXufyRdiscoUhK4Gax+jAK o45gcLgyDpUIoFN73rmLySc3Qe7klnUNGh7i/3cNXUFJd68NFastGv70e1MmN9hYZfDy 5D2bPODUiyTwc8xYIiwpo/nZBbWhMhfnVibxWMRYOB+zbLKIhp8AHeM9bawC9y/y8oKF bOozd5fhet0897aStGfzgiqTTgPz2Bs0E+FeoNo6TA1L9JYYoIj2RHAkFzGOqdx8xd05 qDh2XydiB0pPoxpvzgei8vD8YGFDvQ9AAeiHTAKDf6YPG8kSXUVcGVis7wlX3vHWf+Wx +p0g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1759498737; x=1760103537; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=5yvbWhTiB0g5MKRQJDvE9eSL8LzKl9DcqfgxeSAHNnQ=; b=JZh3mmbDUV+wc/IOL9QqjT5iMURMljleq5eYHwdCXsC4xIGiECKavSCGYzWJ9ndbBz AntPVRwkc+qYFe9eKcym/e/Dvk7SDNw5D8iC3jz3EQxr0BV5+l259NvP8f+qz6fLi19S 8qOYLxUOWlTPAdmM5GJYsKxYpcB+9S/W+zeZXHGddWPpqtKBCuEFY1EnatRI8+fWL+H9 +sNnvddwLILZXWykRdv2A/I+HHaSl6XnekTkLubeeAZjvYp0xUye1f/w5rAOhUfpElZz s5yetiw0QKYuR9NJHQ+moDMm48wJpMjSI1DDgc3IOSDwf4uxpfjh5rdybMYqcmKichuJ k6aw== X-Forwarded-Encrypted: i=1; AJvYcCVPWq7xtyrPq/TzvHgWQyVxTIhej3LjIvwK6IXYlESv6oEB2c/uU7PzNi2kmE7oWGUpzcKQjnRbF1hluQ+djF7Gu1U=@vger.kernel.org X-Gm-Message-State: AOJu0Yz4bsyMeDI+ame4UkoktD1HL8LElhQBOhDXYBE7w1GL/ZN5pxCL 2cruhLgUy2zXnQl6Wrf5cL+aJqOTrAp/A3Xk+iPEL3vOSKiUsrnOEgVZq3KRGLrpfnyMawmEKy/ DXPkF8QrAeg329ElCdU1tQA== X-Google-Smtp-Source: AGHT+IEDmCVx4kHhiREAX0skvRTb6ED4U7OtfqA8ZOw1gh/kLPh63qYxbg7uCqtcVIZm2PCNUon2JI3FP9RVn5iq X-Received: from ejcsa18.prod.google.com ([2002:a17:907:6d12:b0:b3b:b79e:764]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a17:906:4789:b0:b04:1249:2b24 with SMTP id a640c23a62f3a-b49c3933062mr408664166b.37.1759498737576; Fri, 03 Oct 2025 06:38:57 -0700 (PDT) Date: Fri, 3 Oct 2025 14:37:58 +0100 In-Reply-To: <20251003133825.2068970-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251003133825.2068970-1-vdonnefort@google.com> X-Mailer: git-send-email 2.51.0.618.g983fd99d29-goog Message-ID: <20251003133825.2068970-2-vdonnefort@google.com> Subject: [PATCH v7 01/28] ring-buffer: Add page statistics to the meta-page From: Vincent Donnefort To: rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-trace-kernel@vger.kernel.org, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, jstultz@google.com, qperret@google.com, will@kernel.org, aneesh.kumar@kernel.org, kernel-team@android.com, linux-kernel@vger.kernel.org, Vincent Donnefort Content-Type: text/plain; charset="UTF-8" Add two fields pages_touched and pages_lost to the ring-buffer meta-page. Those fields are useful to get the number of used pages in the ring-buffer. Signed-off-by: Vincent Donnefort diff --git a/include/uapi/linux/trace_mmap.h b/include/uapi/linux/trace_mmap.h index c102ef35d11e..e8185889a1c8 100644 --- a/include/uapi/linux/trace_mmap.h +++ b/include/uapi/linux/trace_mmap.h @@ -17,8 +17,8 @@ * @entries: Number of entries in the ring-buffer. * @overrun: Number of entries lost in the ring-buffer. * @read: Number of entries that have been read. - * @Reserved1: Internal use only. - * @Reserved2: Internal use only. + * @pages_lost: Number of pages overwritten by the writer. + * @pages_touched: Number of pages written by the writer. */ struct trace_buffer_meta { __u32 meta_page_size; @@ -39,8 +39,8 @@ struct trace_buffer_meta { __u64 overrun; __u64 read; - __u64 Reserved1; - __u64 Reserved2; + __u64 pages_lost; + __u64 pages_touched; }; #define TRACE_MMAP_IOCTL_GET_READER _IO('R', 0x20) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 43460949ad3f..2c157cb86989 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -6113,6 +6113,8 @@ static void rb_update_meta_page(struct ring_buffer_per_cpu *cpu_buffer) meta->entries = local_read(&cpu_buffer->entries); meta->overrun = local_read(&cpu_buffer->overrun); meta->read = cpu_buffer->read; + meta->pages_lost = local_read(&cpu_buffer->pages_lost); + meta->pages_touched = local_read(&cpu_buffer->pages_touched); /* Some archs do not have data cache coherency between kernel and user-space */ flush_kernel_vmap_range(cpu_buffer->meta_page, PAGE_SIZE); -- 2.51.0.618.g983fd99d29-goog