From: Linkui Xiao <[email protected]>
ixgbe_devlink_reload_empr_finish() is the .reload_up devlink operation,
so it always runs in process context with the devlink instance lock held.
Its polling loop delays with mdelay(500), i.e. it spins the CPU for half
a second per iteration and, because the loop bound is 20 iterations, for
up to ten seconds. That keeps a CPU fully occupied while the firmware
performs the EMP reset, and on CONFIG_PREEMPT_NONE it also makes the
loop non-preemptible for that whole window. The loop does not need to be
atomic and holds no spinlock.
Use msleep() instead.
Fixes: c9e563cae19e ("ixgbe: add support for devlink reload")
Reviewed-by: Przemek Kitszel <[email protected]>
Signed-off-by: Linkui Xiao <[email protected]>
---
v1:https://lore.kernel.org/all/[email protected]/
v2:
- Reworded the commit message: mdelay() does not mask interrupts or
disable preemption, and the ~10 s window is below the soft lockup /
RCU stall thresholds. State the actual rationale instead.
- Split the macro rename into a separate patch.
- The mdelay() -> msleep() change itself is unchanged, so the
Reviewed-by tag is kept.
drivers/net/ethernet/intel/ixgbe/devlink/devlink.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/ixgbe/devlink/devlink.c
b/drivers/net/ethernet/intel/ixgbe/devlink/devlink.c
index cf8908b82f8a..781f13240a0d 100644
--- a/drivers/net/ethernet/intel/ixgbe/devlink/devlink.c
+++ b/drivers/net/ethernet/intel/ixgbe/devlink/devlink.c
@@ -460,7 +460,7 @@ static int ixgbe_devlink_reload_empr_finish(struct devlink
*devlink,
* may be not cleared yet, so begin the loop with the delay
* in order to not check the not updated register.
*/
- mdelay(500);
+ msleep(500);
fwsm = IXGBE_READ_REG(hw, IXGBE_FWSM(hw));
--
2.25.1
