From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (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 5539535294E for ; Sat, 31 Jan 2026 13:29:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769866168; cv=none; b=BUzWJgvmH9qZAGF0R2G3JITLjoEnZtWmSu+AgGcWPXZ1dhq9hFO4WKBe/S61u9IUxrDLroSLUdG5R7CoZWCSMBtl2U0OyjiASvDGAMMnxIeNrAjfmzjzvW2I9Jye9DoqKBe2VJlzIzmdBW0SChNMjSsYEn909BAJNK1V8PayQSg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769866168; c=relaxed/simple; bh=YpT43noux36Qb8SPRAxAVRkhFfy4HwaeXM5l7XWGGkw=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=AE/iAAwz/MEFaY4UeJ2jc7Aq+URk5m8c9VtB6aDQpzjCKfS3r/WtNpPFsF3KP+0hw7VEbnLBnRvfADYUxttr3d68a5Ms6kl3WUF/hycin3mxITJeOL31dxFWRqP123kxY7Z7Ie1bnhesTWX62uPOd0u29qSs1WVCDypcX01IZlQ= 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=VI7q487C; arc=none smtp.client-ip=209.85.128.74 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="VI7q487C" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-4802bb29400so37325575e9.0 for ; Sat, 31 Jan 2026 05:29:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1769866163; x=1770470963; 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=AZUIc60w8aDIxM9yUNkpf1enaQr7Rd+FSbamqcyyReA=; b=VI7q487CmZOIo+01B4R9MgNl5VKEa6WkOnkToDmYxHeSqH4Qejfj662WMwJKMENhWm HuQI5h4Bq83fZQ/P9c9z45V2LqvLAqDbB+bd7n7Yzt9ui6kTv9PzU3vvw6T8/8Mllg6d acRTPjJGjtZuTV5Qi2C6/erZfErlv9q2A+/4ItbM9AG5e5BD2HAkMG+yk1GdXEgbe8Ef OuAUtMWdrRVovAFIrvqhYTOpTDDsNnJ6h3kp0jB/xX8xwyB4B6E4rHWuJnHl8DLoE56S tDOT3ggKgFcIM/PzOfbQFNmKi4GjQctkjSogCpmp6exKhwtCM3fQ/jb7wtWOh9KyLg9s A5vw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769866163; x=1770470963; 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=AZUIc60w8aDIxM9yUNkpf1enaQr7Rd+FSbamqcyyReA=; b=ZglZNZd2JVzA8rWAMpb6fAik36qKd7dpYKvEB08TBxk/8Zfe+0+71J9RZbFZvS9lst 8jVoSjALr3dvordj6si/udmXx3sRojkwxWxVtlTKNj15eKp36P+00Af3gHCSs+Zey5+z SSfayI2yglU4WXkc9PtbpzzfrjeDKF7K/J+RHSQzZWI2mENXi65aPfaGc6D7DOJt/OvC gd4MM6Y4aM4x7LwHJX6GMAONaHdrf10mVSuJHkUTWmzMh93CR4G1y8jDQ1HCn/90H55S w2PkdKw6uUY/fAzDaSLoeL+hBc6yaWjLG8SihxU90suRrN9GLMIMQgAMEYO/Z3F4nz1U 3RLg== X-Forwarded-Encrypted: i=1; AJvYcCUyYUFy/b5aqRQuPoyqsxsleD+ACYiDO95b5I0IF7QX4ytS7parrHR5XPYec5uU27DVGDt+oiz5XmTY7Qw2L6P4CTM=@vger.kernel.org X-Gm-Message-State: AOJu0YxdYD/BdapoaeOrMMlLZQmSkDSBtugbTjOHaxzGelxn+ep8LAXr dnBuRgdQ+75LPtKAhc6DToNCtTVavY3D0B/TjXau5fL/qyCWUCz1VDaFzQLn8dHL1q1TVJKzVTU 2EFoN+vlBbA10VtPcOfhRBg== X-Received: from wrfi9.prod.google.com ([2002:a5d:5849:0:b0:435:a2c9:8c02]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:4ec7:b0:47b:da85:b9ef with SMTP id 5b1f17b1804b1-482db463c13mr79331465e9.16.1769866162768; Sat, 31 Jan 2026 05:29:22 -0800 (PST) Date: Sat, 31 Jan 2026 13:28:19 +0000 In-Reply-To: <20260131132848.254084-1-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: <20260131132848.254084-1-vdonnefort@google.com> X-Mailer: git-send-email 2.53.0.rc1.225.gd81095ad13-goog Message-ID: <20260131132848.254084-2-vdonnefort@google.com> Subject: [PATCH v11 01/30] 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. Reviewed-by: Steven Rostedt (Google) 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 630221b00838..1187d632dd5d 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -6131,6 +6131,8 @@ 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); -- 2.53.0.rc1.225.gd81095ad13-goog