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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shakeel Butt , Jann Horn , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, Ingo Molnar , Will Deacon , Boqun Feng , Waiman Long , Sebastian Andrzej Siewior , Clark Williams , Steven Rostedt Subject: Re: [PATCH RESEND 1/3] locking: add rwsem_is_write_locked(), update non-lockdep asserts Message-ID: <20260116151215.GH831050@noisy.programming.kicks-ass.net> References: <8e343ccb9319433364f5949a69519f1bb521fc8a.1768569863.git.lorenzo.stoakes@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8e343ccb9319433364f5949a69519f1bb521fc8a.1768569863.git.lorenzo.stoakes@oracle.com> X-Stat-Signature: uekftwpm37wqndkgoo7oqmy9dzmdj6jh X-Rspam-User: X-Rspamd-Queue-Id: C20E8140008 X-Rspamd-Server: rspam08 X-HE-Tag: 1768576341-147552 X-HE-Meta: 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 iJpmRoYy UwPS6MlaSfy1fOdGsCooJ2UZfAnbi3VpfZm8PtzSkBKk3cVnG6W4kukDV5uuXvQg1kykDZjX4ea4HK87+jJHq2CZU8/MNFIzAJNz9JcLcgZ6Ukkfp6owsUSqI+Eyk2NZVthugFH8rj8TKbR87UB3SGFnT03pmbLxJ15oea/73xdxCKM9hPkkF/Q7S8kI/FwliNSBCParFBSMVTI7BVlg7cu1JZaIKCzwfHjihNIyNX10LbUY/jBb2CiRl7zePqw+syCMt0fD1FHrO3p6L/O9MgHJBsoJjHbeEE7YVoeBg/RjaTA4BV+9i2mDhSH4bbF/Oww7QQs2ufzY7vDH/sE6Mx/T7epVU6KL6f/Sg X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, 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 Fri, Jan 16, 2026 at 01:36:45PM +0000, Lorenzo Stoakes wrote: > As part of adding some additional lock asserts in mm, we wish to be able to > determine if a read/write semaphore is write-locked, so add > rwsem_is_write_locked() to do the write-lock equivalent of > rwsem_is_locked(). > > While we're here, update rwsem_assert_[write_]held_nolockdep() to utilise > the rwsem_is_[write_]locked() helpers directly to reduce code duplication, > and also update rwsem_is_locked() to take a const rwsem and return a > boolean. There is a long history of abuse of _is_locked() primitives. I don't suppose you read the email thread that led to rwsem_assert_held_*_nolockdep() by any chance?