Patch 0c52310f2600 ("hrtimer: Ignore slack time for RT tasks in schedule_hrtimeout_range()")
effectivelly shortens a sleep in a polling function in the driver.
That is causing a perfomance regression as the new value
of just 2us is too low. In certain test the perf drop is ~30%.
Fix this by adjusting the sleep to 20us (close to the previous value).
Reported-by: Jan Jurca <jjurca@xxxxxxxxxx>
Signed-off-by: Tomas Henzl <thenzl@xxxxxxxxxx>
---
drivers/scsi/mpi3mr/mpi3mr.h | 2 +-
drivers/scsi/mpi3mr/mpi3mr_fw.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/mpi3mr/mpi3mr.h b/drivers/scsi/mpi3mr/mpi3mr.h
index dc2cdd5f0311..249c1a7285d6 100644
--- a/drivers/scsi/mpi3mr/mpi3mr.h
+++ b/drivers/scsi/mpi3mr/mpi3mr.h
@@ -178,7 +178,7 @@ extern atomic64_t event_counter;
#define MPI3MR_DEFAULT_SDEV_QD 32
/* Definitions for Threaded IRQ poll*/
-#define MPI3MR_IRQ_POLL_SLEEP 2
+#define MPI3MR_IRQ_POLL_SLEEP 20
#define MPI3MR_IRQ_POLL_TRIGGER_IOCOUNT 8
/* Definitions for the controller security status*/
diff --git a/drivers/scsi/mpi3mr/mpi3mr_fw.c b/drivers/scsi/mpi3mr/mpi3mr_fw.c
index c196dc14ad20..5695c95fca15 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_fw.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_fw.c
@@ -710,7 +710,7 @@ static irqreturn_t mpi3mr_isr_poll(int irq, void *privdata)
mpi3mr_process_op_reply_q(mrioc,
intr_info->op_reply_q);
- usleep_range(MPI3MR_IRQ_POLL_SLEEP, 10 * MPI3MR_IRQ_POLL_SLEEP);
+ usleep_range(MPI3MR_IRQ_POLL_SLEEP, MPI3MR_IRQ_POLL_SLEEP);
} while (atomic_read(&intr_info->op_reply_q->pend_ios) &&
(num_op_reply < mrioc->max_host_ios));
--
2.45.2
