From: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
The wait_event_timeout macro already tests the condition as its first
action, so there is no reason to open code another version of this, all
that does is skip the might_sleep() debugging in common cases, which is
not helpful.
Further, based on prior patches, we can no simplify the required condition
test:
- If range is valid memory then so is range->hmm
- If hmm_release() has run then range->valid is set to false
at the same time as dead, so no reason to check both.
- A valid hmm has a valid hmm->mm.
Also, add the READ_ONCE for range->valid as there is no lock held here.
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
---
include/linux/hmm.h | 12 ++----------
1 file changed, 2 insertions(+), 10 deletions(-)
diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index 2a7346384ead13..7f3b751fcab1ce 100644
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -216,17 +216,9 @@ static inline unsigned long hmm_range_page_size(const struct hmm_range *range)
static inline bool hmm_range_wait_until_valid(struct hmm_range *range,
unsigned long timeout)
{
- /* Check if mm is dead ? */
- if (range->hmm == NULL || range->hmm->dead || range->hmm->mm == NULL) {
- range->valid = false;
- return false;
- }
- if (range->valid)
- return true;
- wait_event_timeout(range->hmm->wq, range->valid || range->hmm->dead,
+ wait_event_timeout(range->hmm->wq, range->valid,
msecs_to_jiffies(timeout));
- /* Return current valid status just in case we get lucky */
- return range->valid;
+ return READ_ONCE(range->valid);
}
/*
--
2.21.0
