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Thu, 18 Jun 2020 08:20:42 -0700 (PDT) To: linux-mm From: Jens Axboe Subject: schedule/sleep over mmget() Message-ID: <398032e7-7cbf-3a28-75a7-f6586465f0c6@kernel.dk> Date: Thu, 18 Jun 2020 09:20:40 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 84B2E180873CF X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 X-Bogosity: Ham, tests=bogofilter, spamicity=0.011888, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi, Got a question that I couldn't immediately find an answer to. io_uring currently jumps through a few hoops to avoid holding a process mm over schedule, and it doesn't look like that's necessary. Is it fine for a kthread to do mmget/kthread_use_mm at the start, and only put/unuse when it exits? Or is it more prudent to drop/re-acquire over schedule for potential longer periods of idleness? Thanks, -- Jens Axboe