Messages in this thread | | | Date | Mon, 5 Feb 2024 11:09:37 +0000 | From | Jonathan Cameron <> | Subject | Re: [PATCH 1/2] cleanup: Add cond_guard() to conditional guards |
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On Sun, 4 Feb 2024 18:31:04 +0100 "Fabio M. De Francesco" <fabio.maria.de.francesco@linux.intel.com> wrote:
> Add cond_guard() macro to conditional guards. > > cond_guard() is a guard to be used with the conditional variants of locks, > like down_read_trylock() or mutex_lock_interruptible(). > > It takes a statement (or more statements in a block) that is passed to its > second argument. That statement (or block) is executed if waiting for a > lock is interrupted or if a _trylock() fails in case of contention. > > Usage example: > > cond_guard(rwsem_read_try, { printk(...); return 0; }, &semaphore); > > Consistenly with the other guards, locks are unlocked at the exit of the Spell check.
> scope where cond_guard() is called. > > Cc: Peter Zijlstra <peterz@infradead.org> > Suggested-by: Dan Williams <dan.j.williams@intel.com> > Suggested-by: Ira Weiny <ira.weiny@intel.com> > Signed-off-by: Fabio M. De Francesco <fabio.maria.de.francesco@linux.intel.com> > --- > include/linux/cleanup.h | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h > index c2d09bc4f976..3826e8ed4e09 100644 > --- a/include/linux/cleanup.h > +++ b/include/linux/cleanup.h > @@ -134,6 +134,16 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ > * an anonymous instance of the (guard) class, not recommended for > * conditional locks. > * > + * cond_guard(name, fail, args...): > + * a guard to be used with the conditional variants of locks, like > + * down_read_trylock() or mutex_lock_interruptible. 'fail' are one or more > + * statements that are executed if waiting for a lock is interrupted or > + * if a _trylock() fails in case of contention. > + * > + * Example: > + * > + * cond_guard(rwsem_read_try, { printk(...); return 0; }, &semaphore); > + * > * scoped_guard (name, args...) { }: > * similar to CLASS(name, scope)(args), except the variable (with the > * explicit name 'scope') is declard in a for-loop such that its scope is > @@ -165,6 +175,10 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ > > #define __guard_ptr(_name) class_##_name##_lock_ptr > > +#define cond_guard(_name, _ret, args...) \ > + CLASS(_name, scope)(args); \ > + if (!__guard_ptr(_name)(&scope)) _ret
Use the naming that scoped_cond_guard() uses: _fail rather than _ret
> + > #define scoped_guard(_name, args...) \ > for (CLASS(_name, scope)(args), \ > *done = NULL; __guard_ptr(_name)(&scope) && !done; done = (void *)1)
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