diff options
| author |   NeilBrown <neilb@suse.de> | 2024-09-25 15:31:43 +1000 |
|---|---|---|
| committer |   Peter Zijlstra <peterz@infradead.org> | 2024-10-07 09:28:39 +0200 |
| commit | 80681c04c5e8e4297b9ebf201ca3ce6242aa16c3 (patch) | |
| tree | 65bb141151c5b3d9c4c640a515b23d45b885f6bc | |
| parent | sched: Add wait/wake interface for variable updated under a lock. (diff) | |
| download | wireguard-linux-80681c04c5e8e4297b9ebf201ca3ce6242aa16c3.tar.xz wireguard-linux-80681c04c5e8e4297b9ebf201ca3ce6242aa16c3.zip | |
sched: add wait_var_event_io()
It is not currently possible to wait wait_var_event for an io_schedule()
style wait. This patch adds wait_var_event_io() for that purpose.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240925053405.3960701-7-neilb@suse.de
Diffstat (limited to '')
| -rw-r--r-- | include/linux/wait_bit.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/include/linux/wait_bit.h b/include/linux/wait_bit.h index 6aea10efca3d..6346e26fbfd1 100644 --- a/include/linux/wait_bit.h +++ b/include/linux/wait_bit.h @@ -281,6 +281,9 @@ __out: __ret; \ #define __wait_var_event(var, condition) \ ___wait_var_event(var, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ schedule()) +#define __wait_var_event_io(var, condition) \ + ___wait_var_event(var, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ + io_schedule()) /** * wait_var_event - wait for a variable to be updated and notified @@ -306,6 +309,34 @@ do { \ __wait_var_event(var, condition); \ } while (0) +/** + * wait_var_event_io - wait for a variable to be updated and notified + * @var: the address of variable being waited on + * @condition: the condition to wait for + * + * Wait for an IO related @condition to be true, only re-checking when a + * wake up is received for the given @var (an arbitrary kernel address + * which need not be directly related to the given condition, but + * usually is). + * + * The process will wait on a waitqueue selected by hash from a shared + * pool. It will only be woken on a wake_up for the given address. + * + * This is similar to wait_var_event(), but calls io_schedule() instead + * of schedule(). + * + * The condition should normally use smp_load_acquire() or a similarly + * ordered access to ensure that any changes to memory made before the + * condition became true will be visible after the wait completes. + */ +#define wait_var_event_io(var, condition) \ +do { \ + might_sleep(); \ + if (condition) \ + break; \ + __wait_var_event_io(var, condition); \ +} while (0) + #define __wait_var_event_killable(var, condition) \ ___wait_var_event(var, condition, TASK_KILLABLE, 0, 0, \ schedule()) |