From nobody Mon Feb 9 23:04:15 2026 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 1110776410 for ; Fri, 16 May 2025 13:40:37 +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=1747402840; cv=none; b=Sp2TVjkLLcdDTdaUqLVZxmWLM5ZU19Qi2Ccf/IHGm0OmuBCUutheb5LTHzaTNaClhGC7Ygcq6xqoD9xcRzzoGkNHoVnffFAnS4sDLwPWZS9sGjBNGWQmp8Iq29MptitDhXzfQAETybCHE4U1YLpPXcZcE6CVrF+mJKLNqwQVSlo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747402840; c=relaxed/simple; bh=jW2FQ7nR3yq5w2QPtsWE3vTL5Z5sb0QhuRmmVZzGC8M=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ZWsH8RGPRVFvnB/x5fPNJhNw23kluHHdN2+kG32U10vO/2zbkvyuzaqU8CdzedjLKWj5wdJlObEpYjczNwriO5hq3dKQccdh62w3khhFoomKuKH7xGWZEzXcDViqoc2//zY4/K3uRyGo7LRB8fRnR1TVejFATBsoaIYhAnlAsFU= 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=ZOm98nBs; 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="ZOm98nBs" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-43d5ca7c86aso12202875e9.0 for ; Fri, 16 May 2025 06:40:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1747402836; x=1748007636; 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=pTgve1xWELrcXmzWf6SXpdMIqoD+DsmzRfBMgyMmWFg=; b=ZOm98nBsY3qZlhFlc7IAvKR+wifU3V5GBiiXKLJVfJ3R/KGcEgZ+KVP7L0gZjpVxCY cW6qr//FWj+zFgEXTNlANcvUA0j9j9ByzgAMK3NYh9w39p6e49UUiS67vLIwxRARDaZ0 bf9mM0EKfCfr/rr+JyxXMoxegt/+aMudrq1L6EqSiq82WFwnPvdpqgE0VgyjkrbGXd35 OdLsparZsL5qOtDTg2nbuAlgp2iIPxp0DFkK1B33RZr8ckJMVGkZ0IFT6HK/gkifpk1S 2eDMrDFuTeW6atE2AJebiVGxWo+mVtMWBXDLPYnN1DTCfV+9i6LL7kKWdDqjPMy42Jn4 q+VA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1747402836; x=1748007636; 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=pTgve1xWELrcXmzWf6SXpdMIqoD+DsmzRfBMgyMmWFg=; b=l/izAe2HCDaNny/S6m/PUsPTYAFHcZWRxEGMWSy7aF5Tmqp5K3LRPaqjUa0uWVXwlx YDgsfJ8gAsPIGIn4KzKqov9LwLKDmx+5efnzuGCXgZIcathjF9S+KLx9bSBrH8umCZNV 4KJ+B3gPJicplYZsq9Cdrbj8sPqaggNOOueDNHk0O3rZ6gKAUakJVbpnh0O7f8tCIufv NNxujQiQNiMSaEZ3OgYXwzYmnW6HBzxcFqTUQQcUPuFuAT0Th6pU9BZHH+TH32kltDa8 vTBEUZNVMhHJliasVCWgcAOdIJo7J/0qoOqrykLH812TJadoXUNjV9FjhKxs8zb5UI2Y y60w== X-Forwarded-Encrypted: i=1; AJvYcCWEk/KCKhpRgZJVvGXU6GunlsznNgiJJhTr1ni/PPLSfnwMtxRvx/Lfm0RPhQsrvwH0vJHp67RwH3ZK4jk=@vger.kernel.org X-Gm-Message-State: AOJu0YwTBWOLjBSx90Tye+FeethgJN7NHazdxYp6ZtNuP5tHFq17+dVG J2eYqcieTXJFPQLRYnyTdotoMI6bwADFafdRxKS6JUYW15NMEnonjVcB1x6MLqj86kYppudQ2dP +0b7Yu284bGIoplY6kszEig== X-Google-Smtp-Source: AGHT+IFL0LVuDvqNNVcVOoiBdDx5TazIXVwWBCNVMeYAJMsyUHLfmYM0SukSyOsyeQgmX+rhBkYVWkj0+YJRRVQg X-Received: from wmbfl14.prod.google.com ([2002:a05:600c:b8e:b0:43d:4ba5:b5d6]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:609a:b0:43c:fbba:41ba with SMTP id 5b1f17b1804b1-442fd6785acmr28243685e9.28.1747402836485; Fri, 16 May 2025 06:40:36 -0700 (PDT) Date: Fri, 16 May 2025 14:40:07 +0100 In-Reply-To: <20250516134031.661124-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250516134031.661124-1-vdonnefort@google.com> X-Mailer: git-send-email 2.49.0.1101.gccaa498523-goog Message-ID: <20250516134031.661124-2-vdonnefort@google.com> Subject: [PATCH v5 01/25] 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, kernel-team@android.com, linux-kernel@vger.kernel.org, Vincent Donnefort Content-Transfer-Encoding: quoted-printable 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_mma= p.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; =20 - __u64 Reserved1; - __u64 Reserved2; + __u64 pages_lost; + __u64 pages_touched; }; =20 #define TRACE_MMAP_IOCTL_GET_READER _IO('R', 0x20) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 3f9bf562beea..06214588c05a 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -6016,6 +6016,8 @@ static void rb_update_meta_page(struct ring_buffer_pe= r_cpu *cpu_buffer) meta->entries =3D local_read(&cpu_buffer->entries); meta->overrun =3D local_read(&cpu_buffer->overrun); meta->read =3D cpu_buffer->read; + meta->pages_lost =3D local_read(&cpu_buffer->pages_lost); + meta->pages_touched =3D local_read(&cpu_buffer->pages_touched); =20 /* Some archs do not have data cache coherency between kernel and user-sp= ace */ flush_kernel_vmap_range(cpu_buffer->meta_page, PAGE_SIZE); --=20 2.49.0.1101.gccaa498523-goog