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[99.254.144.39]) by smtp.gmail.com with ESMTPSA id i2-20020a37c202000000b007682af2c8aasm4396938qkm.126.2023.09.05.14.42.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 05 Sep 2023 14:42:41 -0700 (PDT) From: Peter Xu To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Anish Moorthy , Axel Rasmussen , Alexander Viro , Mike Kravetz , Peter Zijlstra , Andrew Morton , Mike Rapoport , Christian Brauner , peterx@redhat.com, linux-fsdevel@vger.kernel.org, Andrea Arcangeli , Ingo Molnar , James Houghton , Nadav Amit Subject: [PATCH 3/7] poll: POLL_ENQUEUE_EXCLUSIVE Date: Tue, 5 Sep 2023 17:42:31 -0400 Message-ID: <20230905214235.320571-4-peterx@redhat.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230905214235.320571-1-peterx@redhat.com> References: <20230905214235.320571-1-peterx@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a flag for poll_wait() showing that the caller wants the enqueue to be exclusive. It is similar to EPOLLEXCLUSIVE for epoll() but grants kernel poll users to opt-in with more efficient exclusive queuing where applicable. Signed-off-by: Peter Xu --- fs/select.c | 5 ++++- include/linux/poll.h | 20 ++++++++++++++++++-- 2 files changed, 22 insertions(+), 3 deletions(-) diff --git a/fs/select.c b/fs/select.c index 0433448481e9..a3c9088e8d76 100644 --- a/fs/select.c +++ b/fs/select.c @@ -231,7 +231,10 @@ static void __pollwait(struct file *filp, wait_queue_head_t *wait_address, entry->key = p->_key; init_waitqueue_func_entry(&entry->wait, pollwake); entry->wait.private = pwq; - add_wait_queue(wait_address, &entry->wait); + if (flags & POLL_ENQUEUE_EXCLUSIVE) + add_wait_queue_exclusive(wait_address, &entry->wait); + else + add_wait_queue(wait_address, &entry->wait); } static int poll_schedule_timeout(struct poll_wqueues *pwq, int state, diff --git a/include/linux/poll.h b/include/linux/poll.h index cbad520fc65c..11af98ae579c 100644 --- a/include/linux/poll.h +++ b/include/linux/poll.h @@ -29,6 +29,8 @@ typedef unsigned int poll_flags; +#define POLL_ENQUEUE_EXCLUSIVE BIT(0) + struct poll_table_struct; /* @@ -46,10 +48,24 @@ typedef struct poll_table_struct { __poll_t _key; } poll_table; -static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p) +static inline void __poll_wait(struct file *filp, wait_queue_head_t *wait_address, + poll_table *p, poll_flags flags) { if (p && p->_qproc && wait_address) - p->_qproc(filp, wait_address, p, 0); + p->_qproc(filp, wait_address, p, flags); +} + +static inline void poll_wait(struct file *filp, wait_queue_head_t *wait_address, + poll_table *p) +{ + __poll_wait(filp, wait_address, p, 0); +} + +static inline void poll_wait_exclusive(struct file *filp, + wait_queue_head_t *wait_address, + poll_table *p) +{ + __poll_wait(filp, wait_address, p, POLL_ENQUEUE_EXCLUSIVE); } /* -- 2.41.0