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x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 953CB160004 X-Stat-Signature: adyudwjcqnupxiay191k7u6kntqgkkmw X-Rspam-User: X-Rspamd-Server: rspam01 X-HE-Tag: 1740015691-180185 X-HE-Meta: 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 13jVbzrl q16HEjwYLHR9ogI+TC7l5um2y404fvjNDeogYBNL9F7UWP+My4k/FqgBGw1aPjM/hWEP74Qu/E7lMEHBJZAD7HpgH0sXLgvLShlCqMP/hQcDcZ5beRORquTpzfSpNIRzX4Lf1zhcRRw8/vhPLpOBbZq0xa5yuU2Rz8gPBGXLY6S4Zi6esa7LxGw8QwC4pObwcJNGTksO6ignB0B0v/hg7YhtZvsOp2rv+HZ8UvDA74SZI2iPCK88sZHtMFGCfKJ8mvRI74qLFa0tiLhlp6Ww0wVa2an2rpv6XYpy1ukjwErulhSywTHxzNcKPDyJjwRuPC9Pegw8xBl2LxiVVpM8YnAmNULn8Pj9NISEzUjzz46YTwkNMIbda2e4EB7sUQ0FIk3QE/W+v6A4XYDw= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000002, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, 19 Feb 2025 20:36:13 -0500 Waiman Long wrote: > >>>> this field, we don't need to take lock, though taking the wait_lock may > >>>> still be needed to examine other information inside the mutex. > > Do we need to take it just for accessing owner, which is in an atomic? > > Right. I forgot it is an atomic_long_t. In that case, no lock should be > needed. Now if we have a two fields to read: block_flags (for the type of lock) and blocked_on (for the lock) We need a way to synchronize the two. What happens if we read the type, and the task wakes up and and then blocks on a different type of lock? Then the lock read from blocked_on could be a different type of lock than what is expected. -- Steve