| Message ID | 20190317122258.21760-2-ntsironis@arrikto.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Mike Snitzer |
| Headers | show |
| Series | dm snapshot: Improve performance using a more fine-grained locking scheme | expand |
On Sun, Mar 17, 2019 at 02:22:53PM +0200, Nikos Tsironis wrote: > Commit 1c97be677f72b3 ("list: Use WRITE_ONCE() when adding to lists and > hlists") introduced the use of WRITE_ONCE() to atomically write the list > head's ->next pointer. > > hlist_add_behind() doesn't touch the hlist head's ->first pointer so > there is no reason to use WRITE_ONCE() in this case. > > Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> > Signed-off-by: Ilias Tsitsimpis <iliastsi@arrikto.com> Reviewed-by: Paul E. McKenney <paulmck@linux.ibm.com> > --- > include/linux/list.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/list.h b/include/linux/list.h > index edb7628e46ed..b68d2a85859b 100644 > --- a/include/linux/list.h > +++ b/include/linux/list.h > @@ -743,7 +743,7 @@ static inline void hlist_add_behind(struct hlist_node *n, > struct hlist_node *prev) > { > n->next = prev->next; > - WRITE_ONCE(prev->next, n); > + prev->next = n; > n->pprev = &prev->next; > > if (n->next) > -- > 2.11.0 > -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
diff --git a/include/linux/list.h b/include/linux/list.h index edb7628e46ed..b68d2a85859b 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -743,7 +743,7 @@ static inline void hlist_add_behind(struct hlist_node *n, struct hlist_node *prev) { n->next = prev->next; - WRITE_ONCE(prev->next, n); + prev->next = n; n->pprev = &prev->next; if (n->next)
Commit 1c97be677f72b3 ("list: Use WRITE_ONCE() when adding to lists and hlists") introduced the use of WRITE_ONCE() to atomically write the list head's ->next pointer. hlist_add_behind() doesn't touch the hlist head's ->first pointer so there is no reason to use WRITE_ONCE() in this case. Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Ilias Tsitsimpis <iliastsi@arrikto.com> --- include/linux/list.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)