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[67.48.91.116]) by smtp.gmail.com with ESMTPSA id 586e51a60fabf-24fe0a85880sm2040128fac.4.2024.05.28.20.35.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 28 May 2024 20:35:33 -0700 (PDT) Message-ID: Date: Tue, 28 May 2024 22:35:27 -0500 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 v6 3/4] driver core: shut down devices asynchronously To: Christoph Hellwig Cc: linux-kernel@vger.kernel.org, Greg Kroah-Hartman , "Rafael J . Wysocki" , Tanjore Suresh , Martin Belanger , Oliver O'Halloran , Daniel Wagner , Keith Busch , Lukas Wunner , David Jeffery , Jeremy Allison , Jens Axboe , Sagi Grimberg , linux-nvme@lists.infradead.org References: <20240516154920.221445-1-stuart.w.hayes@gmail.com> <20240516154920.221445-4-stuart.w.hayes@gmail.com> <20240528063109.GA29965@lst.de> Content-Language: en-US From: stuart hayes In-Reply-To: <20240528063109.GA29965@lst.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 5/28/2024 1:31 AM, Christoph Hellwig wrote: > On Thu, May 16, 2024 at 10:49:19AM -0500, Stuart Hayes wrote: >> Add /sys/kernel/async_shutdown to allow user control of this feature: >> >> safe: shut down all devices synchronously, unless driver prefers async >> shutdown (driver opt-in) (default) >> on: shut down all devices asynchronously, unless disabled by the driver >> (driver opt-out) >> off: shut down all devices synchronously > > The on option seems very odd. IMHO safe is the only really sensible > option, and maybe we have to support off as a bandaid due to userspace > behavior dependent on synchronous shutdown, but I'd rather try even > without that first. > I added the option because of comments from Greg K-H on the v4 submission of this patch--see https://lore.kernel.org/lkml/2023102151-rejoicing-studio-6126@gregkh/T/#m5d0459480bc0fda4563040cab2036839bcbb79a8). I thought it would be nice to have the option for testing, even if it gets removed later, but I'll certainly remove it now if necessary.