From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) (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 7C35C364022 for ; Wed, 12 Aug 2026 15:33:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.71 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786548816; cv=none; b=lKgHzehH2p1YN6nDrqRhMDN7mKrgOIzNWFeo85Zi/tkz3YrzuTe3oHG1jfGqK+IRG6zFvXAPwblzZ1P2FZ2W6XGV0+JjLG3MouYPjSrFgeC2P89aCax4mizYTsrNJf0uA1WVJXRD5tPj8O9UTPNvtyx0gL2AGVAQ0YKVr1sNWu0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786548816; c=relaxed/simple; bh=Awl+ndncPDlBmPyWWPeCQSoUZ9lGBiDJC0aJU7naMXU=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=iTPv1o6whvQ4yUIIQ3U76wpzkVE7O9gq/c2ILC2YofCNkHfU2dmH7Sotqjq58Zkt8POdNXjur5pF6ZICVZLY1CqRmdYveSqAi2BAKyJuLJF94AsCl1SyxgVuiazIKTG20kxJ6kyPs3W33a1CpmFcxHDfIQpaiAdOF10OYyET87Q= 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=GLBQ+PXx; arc=none smtp.client-ip=209.85.128.71 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="GLBQ+PXx" Received: by mail-wm1-f71.google.com with SMTP id 5b1f17b1804b1-49554715277so8701465e9.1 for ; Wed, 12 Aug 2026 08:33:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1786548808; x=1787153608; 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=NW7wNIHYXgex6crNczote3UzTjVr5ceZuwNtR9niSYY=; b=GLBQ+PXxcwCiE6CS4/ydj91Onc8VRo+I7VW4zO/HL3y9iyJp1HF/0MByS+9Ome1CNw QJcFvaSyBxbDqi/xaLJGp1PAwmieMvO+UWpJ7e+xUhc50GdHn/mhIeYedbSnXNx378HP EznGWfqS5m/1TYMb/OWHC3S6LcBv+FBE0YIHNz6H8IFyYcYnoqdbooW8FuNdq4vS/7e+ gqmJTG9hBMhHPuWbgUKOPY/WxW6kqnf9NDscwQdP0z0SEIoAC5BP2WD38vICH2LiDRK2 E9Tv4FvHuCji9XcSYru/Hn2IuQxvHfVhN9Gvc4s6XYRFQAg5+9uMxBIgLrHPT4brQduf gayA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786548808; x=1787153608; 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=NW7wNIHYXgex6crNczote3UzTjVr5ceZuwNtR9niSYY=; b=Y++zqWLnI79yc6IiNx7heNKjEEi+q8LWXSAqnh4uDcCCz0erZP7RfJI1kJn2I2bHtP oUeykNTDJqUeoZKqAy+/OekEyJp5myHPJbaR1EURGju0JVmwXQgE8N0yFX30hwkwzxex JFjdwfhrnEe0hmoO1SaaOKTn+o0eEzpDc+iOiNtWtI3NQNMeu+cFJpuHOCFCCl+ffjYP R15X6akM0IaiKNplL5sXleCgzDbqbiUHVWuV+hft1ciq7xWZyk2nqSBtuFwI9pYFhrX7 t0TprZIXsGHmkvjEzVS+GqF0ML1I2G7Jtp14eo1cPXn6bE2T0s9zlaBUSZ3zxw01BU8F 7Zkg== X-Forwarded-Encrypted: i=1; AHgh+RrVSrenWuCQAXMYcIwBIUw8MqqFckPeqzqUTvA8QExpj/6ZxRg2oNbMkFXZH+PMb98OtxT13jzZthrvP6PxmbyZpGU=@vger.kernel.org X-Gm-Message-State: AOJu0Yy+FYt5+0oysAktlqjpoRwNngpPcTBnyhv6Vjow+KKyGkzCdDJ2 Y4mFOK8gBihOvy6G3+M/SDxvcHK8ShpiIzeuAEsLXfBpAZItJlWx9+h01Mbjn7HE3uszFYqD5GP deYhSbRKHgLnvOAL8Xn1WOg== X-Received: from wmfx5.prod.google.com ([2002:a05:600c:2d05:b0:495:4926:42d6]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:468e:b0:499:7a15:fcec with SMTP id 5b1f17b1804b1-4997c127e00mr73513055e9.13.1786548806794; Wed, 12 Aug 2026 08:33:26 -0700 (PDT) Date: Wed, 12 Aug 2026 16:33:01 +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 2.55.0.691.gc56d675ccc-goog Message-ID: <20260812153311.2328812-1-vdonnefort@google.com> Subject: [PATCH v4 0/9] ring-buffer: Fixes for subbuf resizing and persistent buffers 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" This series addresses multiple issues discovered with the dynamic ring buffer resizing. Changelog: v4: - Add rb_subbuf_start() helper (Steven) - kerneldoc additions - Fix races in trace_pipe_raw readers - Use rb_subbuf_capacity() in ring_buffer_subbuf_order_set() - use rb_page_capacity() in ring_buffer_map_get_reader (Sashiko) - Fix 32-bit overflow in ring_buffer_subbuf_order_set() (Sashiko) - Hold cpu_buffer::lock when modifying cpu_buffer->free_page in ring_buffer_subbuf_order_set (Sashiko) v3 (https://lore.kernel.org/all/20260810125633.3344684-1-vdonnefort@google.com/): - Drop first 3 patches (Rebased on 7.2-rc7) - Add a patch to align "nr_pages" to unsigned int - Add a patch to remove useless trace_buffer::cpus - Add unsigned long cast for rb_subbuf_size() - subbuf_order fix for rb_free_cpu_buffer() (Sashiko) - Use __always_inline just like the other accessors for the hot-path. v2 (https://lore.kernel.org/all/20260806211306.3704194-1-vdonnefort@google.com/): - Prevent resizing of the persistent ring buffer - Add missing bpage::order init - Rework subbuf_size/subbuf_order (Sashiko) - Remove ring_buffer_per_cpu::mapped - Dynamically calculate trace_buffer::max_data_size v1 (https://lore.kernel.org/all/20260805153225.2096152-1-vdonnefort@google.com/) Vincent Donnefort (9): ring-buffer: Free cpu_buffer->free_page with subbuf_order ring-buffer: Hold cpu_buffer::lock when resizing a subbuf ring-buffer: Fix subbuf resize race with ring buffer readers ring-buffer: Fix subbuf resize race in ring_buffer_alloc_read_page() tracing: Fix subbuf resize races in trace_pipe_raw readers ring-buffer: Dynamically calculate max_data_size ring-buffer: Remove trace_buffer::cpus ring-buffer: Remove ring_buffer_per_cpu::mapped ring-buffer: Make nr_pages unsigned int include/linux/ring_buffer.h | 4 +- kernel/trace/ring_buffer.c | 354 +++++++++++++++++---------- kernel/trace/ring_buffer_benchmark.c | 2 +- kernel/trace/trace.c | 92 +++---- kernel/trace/trace.h | 1 - 5 files changed, 269 insertions(+), 184 deletions(-) base-commit: db2ddb87143519e20a95aa36c60b36107b736a58 -- 2.55.0.691.gc56d675ccc-goog