From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 275763D3CED for ; Sat, 17 Oct 2026 06:03:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792217000; cv=none; b=boRq3pOXgFBXk/UAjC776lOIjF+Z9pel+9QmSODyyzkS35oTO7rQOZiZnELMcyoKV4YI4I/tDCxW3YyhGo412T5LHAD0hYj9K8N9lCVinu+iq3T9NoOEWE1n8oecWpZPTWCB3junQ8fz6CV2MkSvJ3sbu37d6GLfbqrb8ai9REU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792217000; c=relaxed/simple; bh=dZUqDySn7SZyfiq8NEXHCjPhMYKMYywJqsKsmUiTP00=; h=Message-ID:From:Subject:To:Cc:In-Reply-To:References:Content-Type: Date; b=r1F22KCx32Ur32HnaXhlijnW4Hp6FRvuD34FqXwQL0Rz8wOEvlFxWdCCQEpVs7+3eRRYMj/bX0JKLmvTjYS6bBlNr3HJdodzt5GRu7fX+uswDUSm6HvnDu0xrOcUMZ1bdiUaXqqCAS4RTVP7r25xM+ISwwmmqc8BfqB9X5gkE9M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a2SpCFBl; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="a2SpCFBl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95B721F000C4; Sat, 17 Oct 2026 06:03:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792216998; bh=dZUqDySn7SZyfiq8NEXHCjPhMYKMYywJqsKsmUiTP00=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=a2SpCFBlf93vpsPNWb5VSAy+YlofAO96ezDZtPvF+P4fvqGkPCTBllAe5Cd0N6LkY HDur4ZkQ/k/869uXMZGKJcZCG2QtTe7qj0PmIo6BetLepfjVZvZ1wfJOOpcGx+aFYK 3qdnoDaI8J9mWW7fX9mYA0au6w1WQJmlxSHrKAxQKcOcQ5/Hq6H/0mHEMTNsdih18D N6CsT8szAF7i+eDMDWF+HFsX7Ad7UqhcO/ROpy2tVyIwhuikmkpAbadKTxO9zw+T62 wAs3iBt4oNXCpruN8FQLEueR35kjNoh0KzUA/+3iI0hXDuZoSV3XgzTDJJ3jZpjQCm MLutqjweViCeQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [RFC PATCH 2/2] ALSA: virtio: prioritize staged capture period work Reply-To: sashiko-reviews@lists.linux.dev To: "Joonho Lee" Cc: virtualization@lists.linux.dev, "Michael S. Tsirkin" , "Eugenio Perez" In-Reply-To: References: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sat, 17 Oct 2026 06:03:18 +0000 Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: > CPU contention can delay staged capture period notifications while RX > completions continue filling the unread ring. In a two-vCPU VZ guest with > 16 nice-0 CPU workers, the ACK-fixed baseline stopped with ring_capacity > and EPIPE in three runs, after 11.74, 30.77 and 30.33 seconds of audio. >=20 > Route staged capture period work through system_highpri_wq with a common > helper at all ten producers, including ACK errors and self-requeue. Keep > playback and non-staged streams on the normal workqueue. Initialization, > cancellation, buffer geometry and capture accounting remain unchanged. >=20 > With the same kernel, input, geometry and userspace priority, the candida= te > completed three 70-second captures and immediate reopens. Its maximum > matched queue-to-start delay was 20.366 ms, versus 108.112 ms in the first > baseline failure. The other baseline failures had pending work without > matching execution, so matched-only statistics do not bound that delay. >=20 > Reader scheduling delays were also present. Both arms passed a separate > nice -10 reader control, and host load varied between runs. These results > support the change for the tested workload without isolating a kernel-only > cause or guaranteeing lossless capture under arbitrary CPU load. > KASAN/lockdep QEMU regressions passed with the unchanged candidate source. >=20 > This follows the staged ACK fix and pending VZ capture support. The > introducing staged-capture patch has no upstream Fixes commit ID yet. >=20 > Link: https://lore.kernel.org/all/rfc-v2-vz-capture-compat-1.b9ab4c1540dc= 4691@gmail.com/ > Assisted-by: LLM > Signed-off-by: Joonho Lee Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/rfc-virtio-snd-capt= ure-followups-0.f2737c95c12e45b4@gmail.com?part=3D2