From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A50EED7976B for ; Sat, 31 Jan 2026 13:29:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=AZUIc60w8aDIxM9yUNkpf1enaQr7Rd+FSbamqcyyReA=; b=fq0l8IWZ4/oKfbK76bqSh2tFe/ s3p21YX40MtDOt2Frv/89ME45/45dh/+DKb6OH6g2Fiblwu5whlXZyQFIyivNb6tOWaRfezbsmCc9 s3sz+eYiX70ie6ju5HiJ92NnzYIPXI4R+0t4Ter5EoZo40SJfX2RB0m8asNHryF6QyxuCawq3ES1G 1XQISYaKTNfAAaoYpNSxOuPktmayMzXUUyiAofA+MkGeYF7VtgR+PKM9cV0IblBHIpia3E7ZGRvxw fJxCzykBwVJF/T8UI7dVTidZ/MATYBpswLYM+4xfG3RPifWukSWnSYUkyuKwnWBCRQHV3iMx12djQ v2dy2pFA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vmB2V-00000002bpz-0xMK; Sat, 31 Jan 2026 13:29:27 +0000 Received: from mail-wm1-x34a.google.com ([2a00:1450:4864:20::34a]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vmB2S-00000002bop-3bcz for linux-arm-kernel@lists.infradead.org; Sat, 31 Jan 2026 13:29:26 +0000 Received: by mail-wm1-x34a.google.com with SMTP id 5b1f17b1804b1-477c49f273fso27862305e9.3 for ; Sat, 31 Jan 2026 05:29:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1769866163; x=1770470963; darn=lists.infradead.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=IL3p45rqNrSMdizQBHiW4VW5aCywdc0WJqh2fV8PShH3phbKXtTrrpvJA/nlLxuCd+ f5zblwDjOTGbfjosTIbTn0t3f1tGgRHb8knbx9TIqU1N4lMJovCrj0WhQsLwZmYFtmeQ ebHMwpDViMDuuY2bsQSYmo1dlzTSkG7bmlDP8aYB68eJgNaRJpqa1u0Vn20AaR2ZHa7z C/Pakl32My+4fh5Cvgd0ryXnHqWoZEsdJfOxi2LxT4r5KpaOj28dHHp6GPCZFeb34AHo 5UqoBRm3REgHlUB3bQyCHv74MXoWCNnfpwE4ABES1TEcwwtverdawybMhUdEAs5jodfV W57Q== 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=HclK3L3jLc55jsybjJbJ0MUPpUYpr2EGrL1tE6Xl3ojAZqklAmu2SfQK/Owixa8mQk wpxCblC66jU4/5aUH0WrYZ/VGPRRiAkv0xT08LK3uW19yjFtMamnHf3wjxUnD9KB65Ca iAc2FTpVw84BQHT9ud9Qz9mtcm0AILRzcUki3xGRG8u6NoWohSkZzWrbfPgrJHmaav8U efy5ABWwgSukuJYof9x5aJLVouT9XGVrtGYJ1WEiXuDXeaZbPieuenJKZQFzKs3gJfHI S5vGuByRXWW8lc9owhathzrXRh8mP/+eclz2jJ76XdqMAmSlerj2LD+CMBk7cQNXr8Y+ GrDw== X-Forwarded-Encrypted: i=1; AJvYcCXXcmF/xvVYtMSnGOtckGCRb0ECa+rAI1Nl2YC/6yO8clX/0Ceab+bRwcFhrvSclRJSqFcXdk1kKleb1y7b6BnD@lists.infradead.org X-Gm-Message-State: AOJu0YxVA8+zvlKTR7A7qvoxttkRgpTBUtwF0aeEoiXw+8ehI8/Hf6xt mYdHEN1Pg1ZHWjCrax5EWkDCbq9hySvfnZrMUqh7nYMsihmUoRYmM/IausEB6ky/U2ACEANBWgK zTc5Znm3gP5VgraJfMn8S5A== 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> 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" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260131_052924_903647_964A11B9 X-CRM114-Status: UNSURE ( 9.06 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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