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AJvYcCVtavCm1fQlk9x1w+2QsGKXctFJ6Zxb14U4MrwzwUmwpMKNLChQ58TpfilFYuQkcNY3RjHjFnONgDkL+G07zA02SFNzn88lCt8= X-Gm-Message-State: AOJu0Ywwh5pYglsj4C86QmxMKdb7yKaWmADHo4RTwAnb42RcwueKSnfE zNoU7vvgiuqPBoF5+xZYuosn27rTd29hw39o56Y1M8my6g3AovjNBgYXvrVWAYY= X-Google-Smtp-Source: AGHT+IE/r+6kGQWQgTrRuvZsXt5Jk/7zTOFdGOX/gMa9HL2erOx+JLXrmh+ZxfohkV9kQ/nVsaSU0A== X-Received: by 2002:a05:6a00:6013:b0:6ed:6944:b170 with SMTP id fo19-20020a056a00601300b006ed6944b170mr3128716pfb.1.1713450616403; Thu, 18 Apr 2024 07:30:16 -0700 (PDT) Received: from [192.168.1.150] ([198.8.77.194]) by smtp.gmail.com with ESMTPSA id v10-20020a62ac0a000000b006eadf879a30sm1578618pfe.179.2024.04.18.07.30.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 18 Apr 2024 07:30:15 -0700 (PDT) Message-ID: <5f3d434b-e05c-445f-bee5-2bb1f11a5946@kernel.dk> Date: Thu, 18 Apr 2024 08:30:14 -0600 Precedence: bulk X-Mailing-List: dm-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] completion: move blk_wait_io to kernel/sched/completion.c To: Christoph Hellwig , Mikulas Patocka Cc: Peter Zijlstra , Mike Snitzer , Damien Le Moal , Ingo Molnar , Will Deacon , Waiman Long , Guangwu Zhang , dm-devel@lists.linux.dev, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: <31b118f3-bc8d-b18b-c4b9-e57d74a73f@redhat.com> <20240417175538.GP40213@noisy.programming.kicks-ass.net> <546473fd-ca4b-3c64-349d-cc739088b748@redhat.com> Content-Language: en-US From: Jens Axboe In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/17/24 10:57 PM, Christoph Hellwig wrote: > On Wed, Apr 17, 2024 at 08:00:22PM +0200, Mikulas Patocka wrote: >>>> +EXPORT_SYMBOL(wait_for_completion_long_io); >>> >>> Urgh, why is it a sane thing to circumvent the hang check timer? >> >> The block layer already does it - the bios can have arbitrary size, so >> waiting for them takes arbitrary time. > > And as mentioned the last few times around, I think we want a task > state to say that task can sleep long or even forever and not propagate > this hack even further. It certainly is a hack/work-around, but unless there are a lot more that should be using something like this, I don't think adding extra core complexity in terms of a special task state (or per-task flag, at least that would be easier) is really warranted. -- Jens Axboe