From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-111.freemail.mail.aliyun.com (out30-111.freemail.mail.aliyun.com [115.124.30.111]) (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 B94C013CFB7; Wed, 14 Aug 2024 07:49:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.111 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723621801; cv=none; b=ToBMFPVhLEqEhN/X6u7D8i4Jh1cZqj6wLexOBo0DbsBoanyglQRowfLGWK99l3/7XzXhGulAwLaQDxpg8cMd2gZyay/jIEfeDxTFNuphP6xf0I7CDSsnPQGL32ez0YbVNGPmgpQkAMCddrl2MEo68QlwltEVvgwOz8/OTNJhWD0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723621801; c=relaxed/simple; bh=qjFyWqGVssj1+G9jgMuIQV67hYnTfCZUr57iNzX3JuA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tCju+7nnO45rW9QM9BKUqZ33GOyIPrJh0QXp4KKFBlk9byKoiYyRZPicGbs2UlK+OcVWvE1TUzceoTyi3j1F6pGvAnXk8b3WKXITVGYopzuLOMoNbfGR97sECTuYWKhci4+H+0p7R/1egUa2d8xDENEfNH4W5WEpyjPy9OB3j+M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=pJtdTcKX; arc=none smtp.client-ip=115.124.30.111 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="pJtdTcKX" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1723621795; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=I5pDPKJB+T80C8NVQjfj99TTYk+U6Sl12RWOlJDvLPA=; b=pJtdTcKXQktMWSUiqFrK3/tsPOkJnnPvBTD8wWT4DbuOqxXQ2K0alJbKgkV2PEg+imA5YJ3wEsE0tsiDXad5GfgPASbi6e+ZDTwiG2wKfG0SZwGhQU3pj8jR+bK5BtbkivVNwi9LK3urj1kwqVxu6RSLQV+J3wWoMSLCx4VHndU= Received: from 30.221.146.67(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0WCraOrA_1723621793) by smtp.aliyun-inc.com; Wed, 14 Aug 2024 15:49:54 +0800 Message-ID: <7444ba50-20ba-4908-9f46-0fda488f905b@linux.alibaba.com> Date: Wed, 14 Aug 2024 15:49:52 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 0/2] virtiofs: fix the warning for kernel direct IO To: Hou Tao , linux-fsdevel@vger.kernel.org Cc: Miklos Szeredi , Vivek Goyal , Stefan Hajnoczi , Bernd Schubert , "Michael S . Tsirkin" , Matthew Wilcox , Benjamin Coddington , linux-kernel@vger.kernel.org, virtualization@lists.linux.dev, houtao1@huawei.com References: <20240426143903.1305919-1-houtao@huaweicloud.com> <5d809485-7e29-41ce-b683-7d19b829f86c@linux.alibaba.com> Content-Language: en-US From: Jingbo Xu In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/14/24 3:46 PM, Hou Tao wrote: > Hi, > > On 8/14/2024 2:34 PM, Jingbo Xu wrote: >> Hi, Tao, >> >> On 4/26/24 10:39 PM, Hou Tao wrote: >>> From: Hou Tao >>> >>> Hi, >>> >>> The patch set aims to fix the warning related to an abnormal size >>> parameter of kmalloc() in virtiofs. Patch #1 fixes it by introducing >>> use_pages_for_kvec_io option in fuse_conn and enabling it in virtiofs. >>> Beside the abnormal size parameter for kmalloc, the gfp parameter is >>> also questionable: GFP_ATOMIC is used even when the allocation occurs >>> in a kworker context. Patch #2 fixes it by using GFP_NOFS when the >>> allocation is initiated by the kworker. For more details, please check >>> the individual patches. >>> >>> As usual, comments are always welcome. >>> >>> Change Log: >>> >>> v3: >>> * introduce use_pages_for_kvec_io for virtiofs. When the option is >>> enabled, fuse will use iov_iter_extract_pages() to construct a page >>> array and pass the pages array instead of a pointer to virtiofs. >>> The benefit is twofold: the length of the data passed to virtiofs is >>> limited by max_pages, and there is no memory copy compared with v2. >>> >>> v2: https://lore.kernel.org/linux-fsdevel/20240228144126.2864064-1-houtao@huaweicloud.com/ >>> * limit the length of ITER_KVEC dio by max_pages instead of the >>> newly-introduced max_nopage_rw. Using max_pages make the ITER_KVEC >>> dio being consistent with other rw operations. >>> * replace kmalloc-allocated bounce buffer by using a bounce buffer >>> backed by scattered pages when the length of the bounce buffer for >>> KVEC_ITER dio is larger than PAG_SIZE, so even on hosts with >>> fragmented memory, the KVEC_ITER dio can be handled normally by >>> virtiofs. (Bernd Schubert) >>> * merge the GFP_NOFS patch [1] into this patch-set and use >>> memalloc_nofs_{save|restore}+GFP_KERNEL instead of GFP_NOFS >>> (Benjamin Coddington) >>> >>> v1: https://lore.kernel.org/linux-fsdevel/20240103105929.1902658-1-houtao@huaweicloud.com/ >>> >>> [1]: https://lore.kernel.org/linux-fsdevel/20240105105305.4052672-1-houtao@huaweicloud.com/ >>> >>> Hou Tao (2): >>> virtiofs: use pages instead of pointer for kernel direct IO >>> virtiofs: use GFP_NOFS when enqueuing request through kworker >>> >>> fs/fuse/file.c | 12 ++++++++---- >>> fs/fuse/fuse_i.h | 3 +++ >>> fs/fuse/virtio_fs.c | 25 ++++++++++++++++--------- >>> 3 files changed, 27 insertions(+), 13 deletions(-) >>> >> We also encountered the same issue as [1] these days when attempting to >> insmod a module with ~6MB size, which is upon a virtiofs filesystem. >> >> It would be much helpful if this issue has a standard fix in the >> upstream. I see there will be v4 when reading through the mailing >> thread. Glad to know if there's any update to this series. > > Being busy with other stuff these days. I hope to send v4 before next > weekend. Many thanks, Tao. -- Thanks, Jingbo