From ebdfefc09c6de7897962769bd3e63a2ff443ebf5 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sun, 13 Aug 2023 11:05:36 -0600 Subject: io_uring/sqpoll: fix io-wq affinity when IORING_SETUP_SQPOLL is used If we setup the ring with SQPOLL, then that polling thread has its own io-wq setup. This means that if the application uses IORING_REGISTER_IOWQ_AFF to set the io-wq affinity, we should not be setting it for the invoking task, but rather the sqpoll task. Add an sqpoll helper that parks the thread and updates the affinity, and use that one if we're using SQPOLL. Fixes: fe76421d1da1 ("io_uring: allow user configurable IO thread CPU affinity") Cc: stable@vger.kernel.org # 5.10+ Link: https://github.com/axboe/liburing/discussions/884 Signed-off-by: Jens Axboe --- io_uring/io-wq.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'io_uring/io-wq.c') diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c index 2da0b1ba6a56..62f345587df5 100644 --- a/io_uring/io-wq.c +++ b/io_uring/io-wq.c @@ -1306,13 +1306,16 @@ static int io_wq_cpu_offline(unsigned int cpu, struct hlist_node *node) return __io_wq_cpu_online(wq, cpu, false); } -int io_wq_cpu_affinity(struct io_wq *wq, cpumask_var_t mask) +int io_wq_cpu_affinity(struct io_uring_task *tctx, cpumask_var_t mask) { + if (!tctx || !tctx->io_wq) + return -EINVAL; + rcu_read_lock(); if (mask) - cpumask_copy(wq->cpu_mask, mask); + cpumask_copy(tctx->io_wq->cpu_mask, mask); else - cpumask_copy(wq->cpu_mask, cpu_possible_mask); + cpumask_copy(tctx->io_wq->cpu_mask, cpu_possible_mask); rcu_read_unlock(); return 0; -- cgit v1.2.3-70-g09d2