| Message ID | 20220822114648.989212021@infradead.org (mailing list archive) |
|---|---|
| State | Handled Elsewhere, archived |
| Headers | show |
| Series | Freezer Rewrite | expand |
* Peter Zijlstra <peterz@infradead.org> wrote: > Allows waiting with a custom @state. > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > --- > include/linux/wait.h | 28 ++++++++++++++++++++++++++++ > 1 file changed, 28 insertions(+) > > --- a/include/linux/wait.h > +++ b/include/linux/wait.h > @@ -931,6 +931,34 @@ extern int do_wait_intr_irq(wait_queue_h > __ret; \ > }) > > +#define __wait_event_state(wq, condition, state) \ > + ___wait_event(wq, condition, state, 0, 0, schedule()) > + > +/** > + * wait_event_state - sleep until a condition gets true > + * @wq_head: the waitqueue to wait on > + * @condition: a C expression for the event to wait for > + * @state: state to sleep in > + * > + * The process is put to sleep (@state) until the @condition evaluates to true > + * or a signal is received. The @condition is checked each time the waitqueue > + * @wq_head is woken up. Documentation inconsistency nit: if TASK_INTERRUPTIBLE isn't in @state then we won't wake up when a signal is received. This probably got copy-pasted from a signal variant. > + * > + * wake_up() has to be called after changing any variable that could > + * change the result of the wait condition. > + * > + * The function will return -ERESTARTSYS if it was interrupted by a > + * signal and 0 if @condition evaluated to true. That's not unconditionally true either if !TASK_INTERRUPTIBLE. > +#define wait_event_state(wq_head, condition, state) \ > +({ \ > + int __ret = 0; \ > + might_sleep(); \ Very small style consistency nit, the above should have a newline after local variables: > +#define wait_event_state(wq_head, condition, state) \ > +({ \ > + int __ret = 0; \ > + \ > + might_sleep(); \ Like most (but not all ... :-/ ) of the existing primitives have. Thanks, Ingo
On Sun, Sep 04, 2022 at 11:54:57AM +0200, Ingo Molnar wrote: > > +/** > > + * wait_event_state - sleep until a condition gets true > > + * @wq_head: the waitqueue to wait on > > + * @condition: a C expression for the event to wait for > > + * @state: state to sleep in > > + * > > + * The process is put to sleep (@state) until the @condition evaluates to true > > + * or a signal is received. The @condition is checked each time the waitqueue > > + * @wq_head is woken up. > > Documentation inconsistency nit: if TASK_INTERRUPTIBLE isn't in @state then > we won't wake up when a signal is received. This probably got copy-pasted > from a signal variant. > > > + * > > + * wake_up() has to be called after changing any variable that could > > + * change the result of the wait condition. > > + * > > + * The function will return -ERESTARTSYS if it was interrupted by a > > + * signal and 0 if @condition evaluated to true. > > That's not unconditionally true either if !TASK_INTERRUPTIBLE. --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -942,14 +942,14 @@ extern int do_wait_intr_irq(wait_queue_h * @state: state to sleep in * * The process is put to sleep (@state) until the @condition evaluates to true - * or a signal is received. The @condition is checked each time the waitqueue - * @wq_head is woken up. + * or a signal is received (when allowed by @state). The @condition is checked + * each time the waitqueue @wq_head is woken up. * * wake_up() has to be called after changing any variable that could * change the result of the wait condition. * - * The function will return -ERESTARTSYS if it was interrupted by a - * signal and 0 if @condition evaluated to true. + * The function will return -ERESTARTSYS if it was interrupted by a signal + * (when allowed by @state) and 0 if @condition evaluated to true. */ #define wait_event_state(wq_head, condition, state) \ ({ \ > > +#define wait_event_state(wq_head, condition, state) \ > > +({ \ > > + int __ret = 0; \ > > + might_sleep(); \ > > Very small style consistency nit, the above should have a newline after > local variables: > > > +#define wait_event_state(wq_head, condition, state) \ > > +({ \ > > + int __ret = 0; \ > > + \ > > + might_sleep(); \ > > Like most (but not all ... :-/ ) of the existing primitives have. Yeah, I'm going to leave it as is.
* Peter Zijlstra <peterz@infradead.org> wrote: > On Sun, Sep 04, 2022 at 11:54:57AM +0200, Ingo Molnar wrote: > > > +/** > > > + * wait_event_state - sleep until a condition gets true > > > + * @wq_head: the waitqueue to wait on > > > + * @condition: a C expression for the event to wait for > > > + * @state: state to sleep in > > > + * > > > + * The process is put to sleep (@state) until the @condition evaluates to true > > > + * or a signal is received. The @condition is checked each time the waitqueue > > > + * @wq_head is woken up. > > > > Documentation inconsistency nit: if TASK_INTERRUPTIBLE isn't in @state then > > we won't wake up when a signal is received. This probably got copy-pasted > > from a signal variant. > > > > > + * > > > + * wake_up() has to be called after changing any variable that could > > > + * change the result of the wait condition. > > > + * > > > + * The function will return -ERESTARTSYS if it was interrupted by a > > > + * signal and 0 if @condition evaluated to true. > > > > That's not unconditionally true either if !TASK_INTERRUPTIBLE. > > > --- a/include/linux/wait.h > +++ b/include/linux/wait.h > @@ -942,14 +942,14 @@ extern int do_wait_intr_irq(wait_queue_h > * @state: state to sleep in > * > * The process is put to sleep (@state) until the @condition evaluates to true > - * or a signal is received. The @condition is checked each time the waitqueue > - * @wq_head is woken up. > + * or a signal is received (when allowed by @state). The @condition is checked > + * each time the waitqueue @wq_head is woken up. > * > * wake_up() has to be called after changing any variable that could > * change the result of the wait condition. > * > - * The function will return -ERESTARTSYS if it was interrupted by a > - * signal and 0 if @condition evaluated to true. > + * The function will return -ERESTARTSYS if it was interrupted by a signal > + * (when allowed by @state) and 0 if @condition evaluated to true. > */ Reviewed-by: Ingo Molnar <mingo@kernel.org> > > > +#define wait_event_state(wq_head, condition, state) \ > > > +({ \ > > > + int __ret = 0; \ > > > + \ > > > + might_sleep(); \ > > > > Like most (but not all ... :-/ ) of the existing primitives have. > > Yeah, I'm going to leave it as is. Will queue up a cleanup patch, should I ever notice this detail again ... :-) Thanks, Ingo
--- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -931,6 +931,34 @@ extern int do_wait_intr_irq(wait_queue_h __ret; \ }) +#define __wait_event_state(wq, condition, state) \ + ___wait_event(wq, condition, state, 0, 0, schedule()) + +/** + * wait_event_state - sleep until a condition gets true + * @wq_head: the waitqueue to wait on + * @condition: a C expression for the event to wait for + * @state: state to sleep in + * + * The process is put to sleep (@state) until the @condition evaluates to true + * or a signal is received. The @condition is checked each time the waitqueue + * @wq_head is woken up. + * + * wake_up() has to be called after changing any variable that could + * change the result of the wait condition. + * + * The function will return -ERESTARTSYS if it was interrupted by a + * signal and 0 if @condition evaluated to true. + */ +#define wait_event_state(wq_head, condition, state) \ +({ \ + int __ret = 0; \ + might_sleep(); \ + if (!(condition)) \ + __ret = __wait_event_state(wq_head, condition, state); \ + __ret; \ +}) + #define __wait_event_killable_timeout(wq_head, condition, timeout) \ ___wait_event(wq_head, ___wait_cond_timeout(condition), \ TASK_KILLABLE, 0, timeout, \
Allows waiting with a custom @state. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> --- include/linux/wait.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)