Currently the code enqueues the reset work items on system_long_wq: the
ibmvnic_delayed_reset delayed work using queue_delayed_work(), and the
ibmvnic_reset work using queue_work(). This workqueue should be used when
long works are expected and it is a per-cpu workqueue.
queue_delayed_work() ends up calling __queue_delayed_work(), which, since
IBMVNIC_RESET_DELAY is non-zero, sets a global timer that could fire
anywhere, enqueuing the work where the timer fired. queue_work(), instead,
enqueues the work on the local CPU, i.e. the CPU that requested the reset.
Unbound works could benefit from scheduler task placement, to optimize
performance and power consumption. Long work shouldn't stick to a single
CPU.
Recently, a new unbound workqueue specific for long running work has
been added:
c116737e972e ("workqueue: Add system_dfl_long_wq for long unbound works")
Since the reset work doesn't rely on per-cpu variables, there is no
obvious reason that justify the use of a per-cpu workqueue. So change
system_long_wq with system_dfl_long_wq so that the work may benefit from
scheduler task placement.
Both work items run the same handler, __ibmvnic_reset(), and every reset
request is scheduled through the queue_work() call in ibmvnic_reset().
So convert this call site too, so that all the reset work runs on an
unbound workqueue instead of the CPU that submitted the request.
Cc: Haren Myneni <haren@linux.ibm.com>
Cc: Rick Lindsley <ricklind@linux.ibm.com>
Cc: Nick Child <nnac123@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Cc: <redacted>
Signed-off-by: Marco Crivellari <redacted>
Acked-by: Mingming Cao <redacted>
---
drivers/net/ethernet/ibm/ibmvnic.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 5a510eed335e..d4c284c8ef43 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -3229,7 +3229,7 @@ static void __ibmvnic_reset(struct work_struct *work)
if (adapter->state == VNIC_PROBING &&
!wait_for_completion_timeout(&adapter->probe_done, timeout)) {
dev_err(dev, "Reset thread timed out on probe");
- queue_delayed_work(system_long_wq,
+ queue_delayed_work(system_dfl_long_wq,
&adapter->ibmvnic_delayed_reset,
IBMVNIC_RESET_DELAY);
return;@@ -3267,7 +3267,7 @@ static void __ibmvnic_reset(struct work_struct *work)
spin_lock(&adapter->rwi_lock);
if (!list_empty(&adapter->rwi_list)) {
if (test_and_set_bit_lock(0, &adapter->resetting)) {
- queue_delayed_work(system_long_wq,
+ queue_delayed_work(system_dfl_long_wq,
&adapter->ibmvnic_delayed_reset,
IBMVNIC_RESET_DELAY);
} else {@@ -3454,7 +3454,7 @@ static int ibmvnic_reset(struct ibmvnic_adapter *adapter,
list_add_tail(&rwi->list, &adapter->rwi_list);
netdev_dbg(adapter->netdev, "Scheduling reset (reason %s)\n",
reset_reason_to_string(reason));
- queue_work(system_long_wq, &adapter->ibmvnic_reset);
+ queue_work(system_dfl_long_wq, &adapter->ibmvnic_reset);
ret = 0;
err:
--
2.56.0