From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- io_uring/wait.h | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 io_uring/wait.h (limited to 'io_uring/wait.h') diff --git a/io_uring/wait.h b/io_uring/wait.h new file mode 100644 index 000000000..b7b9c46b1 --- /dev/null +++ b/io_uring/wait.h @@ -0,0 +1,55 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef IOU_WAIT_H +#define IOU_WAIT_H + +#include + +/* + * ->cq_wait_nr is armed with the number of lazy task_work adds the waiter + * still needs, and counted down by the add side, with the add reaching zero + * issuing the (single) wake up for this wait cycle. Zero and below means no + * wake up is to be issued: IO_CQ_WAKE_INIT when no task is waiting (also + * what a forced wake up resets it to when claiming one), zero once the + * countdown has fired. + */ +#define IO_CQ_WAKE_INIT (-1) + +struct ext_arg { + size_t argsz; + struct timespec64 ts; + const sigset_t __user *sig; + ktime_t min_time; + bool ts_set; + bool iowait; +}; + +int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, u32 flags, + struct ext_arg *ext_arg); +int io_run_task_work_sig(struct io_ring_ctx *ctx); +void io_cqring_do_overflow_flush(struct io_ring_ctx *ctx); +void io_cqring_overflow_flush_locked(struct io_ring_ctx *ctx); + +static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx) +{ + struct io_rings *rings = io_get_rings(ctx); + return ctx->cached_cq_tail - READ_ONCE(rings->cq.head); +} + +static inline unsigned int __io_cqring_events_user(struct io_ring_ctx *ctx) +{ + struct io_rings *rings = io_get_rings(ctx); + + return READ_ONCE(rings->cq.tail) - READ_ONCE(rings->cq.head); +} + +/* + * Reads the tail/head of the CQ ring while providing an acquire ordering, + * see comment at top of io_uring.c. + */ +static inline unsigned io_cqring_events(struct io_ring_ctx *ctx) +{ + smp_rmb(); + return __io_cqring_events(ctx); +} + +#endif -- cgit v1.3.1