From: Martin Karsten <mkarsten@xxxxxxxxxxxx>
Setting prefer_busy_poll now leads to an effectively nonblocking
iteration though napi_busy_loop, even when busy_poll_usecs is 0.
Signed-off-by: Martin Karsten <mkarsten@xxxxxxxxxxxx>
Co-developed-by: Joe Damato <jdamato@xxxxxxxxxx>
Signed-off-by: Joe Damato <jdamato@xxxxxxxxxx>
Tested-by: Joe Damato <jdamato@xxxxxxxxxx>
Tested-by: Martin Karsten <mkarsten@xxxxxxxxxxxx>
Acked-by: Stanislav Fomichev <sdf@xxxxxxxxxxx>
Reviewed-by: Sridhar Samudrala <sridhar.samudrala@xxxxxxxxx>
---
v1 -> v2:
- Rebased to apply now that commit b9ca079dd6b0 ("eventpoll: Annotate
data-race of busy_poll_usecs") has been picked up from VFS.
fs/eventpoll.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 1ae4542f0bd8..f9e0d9307dad 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -420,7 +420,9 @@ static bool busy_loop_ep_timeout(unsigned long start_time,
static bool ep_busy_loop_on(struct eventpoll *ep)
{
- return !!READ_ONCE(ep->busy_poll_usecs) || net_busy_loop_on();
+ return !!READ_ONCE(ep->busy_poll_usecs) ||
+ READ_ONCE(ep->prefer_busy_poll) ||
+ net_busy_loop_on();
}
static bool ep_busy_loop_end(void *p, unsigned long start_time)
--
2.25.1
