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 A4553376EC for ; Tue, 9 Jul 2024 06:06:06 +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=1720505170; cv=none; b=hyTT9I4bzLgxuNxfNngyWn1xRsO0v3QUrCeA6VwI3pIh/ECT8jgwQSwr67jGx5d4cQBWKqOsNFS1qqfTlfINEKQUNZan6nb0ZvkDh2h3QegkCUjxfO6Ki5kWpxnXKyUNGWWLxuMujJGedCUYitpLv0vGImeKNwJbro0CoqxafIo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720505170; c=relaxed/simple; bh=8uqzKNrEmauOSfYirU/dvF7EwDXkY5CZ2AQ+hUMtF4k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rdh+SxJrbGUG8LQNz/Jqk9G1dILDie/jIVm/Py3kICq0QRTo54Zpr5jVDT1+cbo53XXC+NRzaR2ikYkj8fwaveuP4ZoT+C3NYGQci5bL2g2RUpiEuiPay2R7cvZ1aS3KvjaCP+6n/3RItJFXiJCUnZ6BU8ZqXeJLqdZmAJTfmEY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (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=oW1Uh8lJ; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (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="oW1Uh8lJ" 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=bYAPwkpALhSjE+Lm99uuIRIa04hDCAnZYqCSZkNAuD8=; b=oW1Uh8lJoq80RFTLL/QPY2npb5 Whw6b2Ubrl85jNE7Iu0xVEpzKajw/SOMXVPOzxEAwWbbKtIq3JHscRs0xhzU9idrgDkb7kvoanscT BKj207STfXUBdxpgJC1Oj9UT3/y7JzS6kRTHhMS1/CG2M+3rXVkWRbjT0DadrJWrvZL5Bv7KGaYDd 2oDb99OJjkO1t7Gguvs504cSXIdE/DOThCQl/aGjOSRtSpOIXcvGG/ZpCFa7wTDCVRBzvP1ixWmoQ xTFDvS58VhqipzyEkiqYlNBLIg5qGcvZ4IRgvmBwiUX0CD2ak/ntu8KD3BjwTIOITZgPu4PU3Ey44 AwtTCu8g==; Received: from hch by bombadil.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1sR3zK-000000060om-0zYj; Tue, 09 Jul 2024 06:06:06 +0000 Date: Mon, 8 Jul 2024 23:06:06 -0700 From: Christoph Hellwig To: Dan Williams Cc: Yee Li , linux-cxl@vger.kernel.org Subject: Re: Is there any plan to support CXL GPF in Linux Message-ID: References: <668c877f86daf_102cc2941b@dwillia2-xfh.jf.intel.com.notmuch> Precedence: bulk X-Mailing-List: linux-cxl@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: <668c877f86daf_102cc2941b@dwillia2-xfh.jf.intel.com.notmuch> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Mon, Jul 08, 2024 at 05:42:39PM -0700, Dan Williams wrote: > One thing that guide does not cover is what should OS software do with a > dirty shutdown failure. To my knowledge there is no specific plumbing > for handling NVME device write-cache failures beyond: "hope filesystem > logging and metadata checksums can recover a consistent filesystem". > > I do agree that the driver has a responsibility to set switch timeout > values, but that is more an unfortunate complexity imposed by the spec. > Just set the max and rely on devices to minimize GPF response times to > avoid the worst case wait times that those timeouts imply. In any event, > enabling that is "up for grabs." Why would anyone specifically care about a (presumably non-volatile) write cache failure? A non-volatile write cache is simply part of the device and it's failure rate guarantee. So any data lost from it will be recovered the same way as a media failure, SOC failure, interconnect failure, etc.