From mboxrd@z Thu Jan 1 00:00:00 1970 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.subspace.kernel.org (Postfix) with ESMTPS id CF9B238B7DE; Fri, 27 Mar 2026 06:27:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774592846; cv=none; b=BkJDm88pMrqw5ZVHmfpwKJ4LzPmdMV/5rHoWofVmnHFUrtx9QCd39uWs9Cv/qBpjc7Zr07ydij+uj7oIGNTpRLt/nGZyw2r+tjZjIIOMSqO4yglOtW/47uMW4OLNzx9h8OHHqrkRkilZ/gs/8Ty1y+sh5MKxbuBpH55ksE4Plp4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774592846; c=relaxed/simple; bh=HC+Bdkwl7K6LiIyuxB7VtyPJr1cnDQ3hdaukOnUHjfo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=lKzuO4Pt8MOOPvfS/jwvZG2TUT8nOvjtyaPCQv+IYxBDcoDX8o0W/zquAcs5EUjYR9PAEGaETdHRDxXpesc00U8prDGilxIoU1TJt8K3c1XMLWiRAtsK5FRCE5dPdI0+EonvBxXiZEeZ/m86LBl9G3fwbLcVlEUHk9OelZNeC4g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=3ozzZMNI; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="3ozzZMNI" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=G7w/DjtHh6UU1dKA9LsKeKfhy2A9T6huT5mWVhBMMqQ=; b=3ozzZMNIwG7iBmBHIggRh8/DLu 8x+FlaRDvryUNTt7u7s70BsPfBhzLzqJcly52Sj8EZXyBrLhdpCOCL8iuerychQUTJuHQGPkibYdX GS2ScIm0cdDILYGgjoitivuR6YBcB0QRpTlt6rYa7PHKjqDsmyqNbCO0YC3wdURLu5RXaTEPQc5c1 Gk+hNp2DXUh+QSndqK8RULVt5f1o2qqnQA2d73cN673EvDHwModjWdMqCjgfM4BPlkCcKKq5jhfRz 4gGaPd7jnOf2B9gVXAEIbxNgQMKIY9VTlhJmAk3gYl/596taDXr+MU4G1eZOZijYf73mgUF8AiCC8 1lq7qTxw==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1w60fA-00000006p8d-1NCq; Fri, 27 Mar 2026 06:27:20 +0000 Date: Thu, 26 Mar 2026 23:27:20 -0700 From: Christoph Hellwig To: Gao Xiang Cc: Christoph Hellwig , Dave Chinner , Tal Zussman , Jens Axboe , "Matthew Wilcox (Oracle)" , Christian Brauner , "Darrick J. Wong" , Carlos Maiolino , Alexander Viro , Jan Kara , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH RFC v4 2/3] iomap: use BIO_COMPLETE_IN_TASK for dropbehind writeback Message-ID: References: <20260325-blk-dontcache-v4-0-c4b56db43f64@columbia.edu> <20260325-blk-dontcache-v4-2-c4b56db43f64@columbia.edu> <9e8061a5-980e-4e6a-a349-8a89f9eb1ba6@linux.alibaba.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9e8061a5-980e-4e6a-a349-8a89f9eb1ba6@linux.alibaba.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Fri, Mar 27, 2026 at 02:24:02PM +0800, Gao Xiang wrote: > - use EROFS directly, in that case, we still need process > contexts to decompress, but due to Android latency > requirements, they really need per-cpu RT threads instead, > otherwise it will cause serious regression too; but I'm not > sure that case can be replaced by this work since workqueues > don't support RT threads and I guess generic block layer > won't be bothered with that too. All of the I/O completions should be latency sensitive. So I think it would be great if you could help out here with the requirements and implementation.