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Wong" , linux-xfs@vger.kernel.org References: <20230907174705.2976191-1-willy@infradead.org> <20230907174705.2976191-2-willy@infradead.org> <2cd975ec-f868-f180-350f-b1b704118777@redhat.com> From: Waiman Long In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 X-Rspamd-Queue-Id: 5FFC912001B X-Rspam-User: X-Stat-Signature: qzn93uf7g4jdbuot6mhqp8sd3pahby4m X-Rspamd-Server: rspam01 X-HE-Tag: 1694120807-681544 X-HE-Meta: U2FsdGVkX1+E4eVXadK0KbFjYccfbUo8KzXmqYQyG00PoNFdu9r2PgjMiCtf2k9LfLhhaGYInZ+3gYQDvEZpuwyFWncCPWdnSed+fehi55y+nQ2DMSn9qwc1amtMFSsiK7b+tN1ak95j5sNGMmuDygEbzIYdEvkwDtesVQFuym1VdIVmLJHav7k1GNqxXQzjOcAufso0KDxYIzShP6CSmYP1LEtTmB5NANJK9XX5UGv98Ww/w4mpFub50ohEJk7j2xYYgj8ILBA2e2B/6dozY0NsxkeTXxnk9qoSbkzOFWF/pXNzxIrlcZlS7nzU46nHT/pTjPhAVt72PFk12kZDFe6LHBRnqOqnSExsXb/YOqY41KDWnvL4p6TjSREAs5G3yMpEdQDBV1mqVuYzytP5azs/42ZVRZflSmdpO9sp8cXWv3cqNxpM+kz380TQ8NoR9iXcyyNaei4JNzYHEyYpj9V4OYIYmRnYOX7iKhVa87MjHvbZXW3giRlEriYRdsaIXNdE5+0b+bQyeUEXLiRBDLvr48h5tkzFgM6XEL3CjYaIBcsMARU1pgCz8UouMfVMaBSNa3SG+XDAhSzf8IUfvmHDW15iKsmE/i9Uwk+1lqaxBMsA7SMgco3T2EcUPbGxrf4QJJod5S+wquQQsZXWcV8E7ycy/8JbTlPOBVLWC5qFbKerEZ34/JOmHJ+7ifnlxaSo+rnh7oTfyhLGm+/GXciv7M2UVK/y4YYjPTmukTmirbMupRPG2lPZDtAMhJjWvzrduqQ2MABdAgtRT5Me99v7k/R6jAOy4B2lB9UN8CRXuT/tg4wLN09ZcUaUAHy3kP/UAKlkl589gTiJN8ho2DedmzUfNT3PbWbkKb88gU1mGKpRe3ZXyNetf+nTj9VQXJn/KxZuouy2KtEK6l6ibdbTHwRQKEoaWVNugkrAWUXIWGjrgZHLxPpCu2qM/vAxhOHP7LZD6fsb6yAmFJc Q133cxql xkrKjBNl/w60S6Xfgd2KLi3zLivGI2owAbEn7Uezwk5QGgWo5m6fzvhdvCoO20h0G7Hti7ThC6oSAve8aqN+WJjU6ZnkvWIjqPUYh/kjYfs3/QKEbohAAXsD4nIYAePra+jSyY8UhREyL542AOIeurOH9+w8Sm5Rw9nBnkLFlzSWfRYOgPkPC8bHmAbbDENspP4JqhCfI2S4tT1c= 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: On 9/7/23 15:33, Matthew Wilcox wrote: > On Thu, Sep 07, 2023 at 02:05:54PM -0400, Waiman Long wrote: >> On 9/7/23 13:47, Matthew Wilcox (Oracle) wrote: >>> +static inline int rwsem_is_write_locked(struct rw_semaphore *sem) >>> +{ >>> + return atomic_long_read(&sem->count) & 1 /* RWSEM_WRITER_LOCKED */; >>> +} >> I would prefer you move the various RWSEM_* count bit macros from >> kernel/locking/rwsem.c to under the !PREEMPT_RT block and directly use >> RWSEM_WRITER_LOCKED instead of hardcoding a value of 1. > Just to be clear, you want the ~50 lines from: > > /* > * On 64-bit architectures, the bit definitions of the count are: > ... > #define RWSEM_READ_FAILED_MASK (RWSEM_WRITER_MASK|RWSEM_FLAG_WAITERS|\ > RWSEM_FLAG_HANDOFF|RWSEM_FLAG_READFAIL) > > moved from rwsem.c to rwsem.h? > > Or just these four lines: > > #define RWSEM_WRITER_LOCKED (1UL << 0) > #define RWSEM_FLAG_WAITERS (1UL << 1) > #define RWSEM_FLAG_HANDOFF (1UL << 2) > #define RWSEM_FLAG_READFAIL (1UL << (BITS_PER_LONG - 1)) I think just the first 3 lines will be enough. Maybe a bit of comment about these bit flags in the count atomic_long value. Cheers, Longman