RDMA/nes: Fix interrupt moderation low threshold
Interrupt moderation low threshold value was incorrectly triggering,
indicating that the threshold should be lowered.
The impact was the timer was likely to become 40usecs and get stuck
there. The biggest side effect was too many interrupts and nonoptimal
performance.
Signed-off-by: John Lacombe <jlacombe@neteffect.com>
Signed-off-by: Glenn Streiff <gstreiff@neteffect.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/nes/nes_hw.c b/drivers/infiniband/hw/nes/nes_hw.c
index 7c4c0fb..49e53e4 100644
--- a/drivers/infiniband/hw/nes/nes_hw.c
+++ b/drivers/infiniband/hw/nes/nes_hw.c
@@ -156,15 +156,14 @@
spin_lock_irqsave(&nesadapter->periodic_timer_lock, flags);
- if (shared_timer->cq_count_old < cq_count) {
- if (cq_count > shared_timer->threshold_low)
- shared_timer->cq_direction_downward=0;
- }
- if (shared_timer->cq_count_old >= cq_count)
+ if (shared_timer->cq_count_old <= cq_count)
+ shared_timer->cq_direction_downward = 0;
+ else
shared_timer->cq_direction_downward++;
shared_timer->cq_count_old = cq_count;
if (shared_timer->cq_direction_downward > NES_NIC_CQ_DOWNWARD_TREND) {
- if (cq_count <= shared_timer->threshold_low) {
+ if (cq_count <= shared_timer->threshold_low &&
+ shared_timer->threshold_low > 4) {
shared_timer->threshold_low = shared_timer->threshold_low/2;
shared_timer->cq_direction_downward=0;
nesdev->currcq_count = 0;
@@ -1728,7 +1727,6 @@
nesdev->int_req &= ~NES_INT_TIMER;
nes_write32(nesdev->regs+NES_INTF_INT_MASK, ~(nesdev->intf_int_req));
nes_write32(nesdev->regs+NES_INT_MASK, ~nesdev->int_req);
- nesadapter->tune_timer.timer_in_use_old = 0;
}
nesdev->deepcq_count = 0;
return 1;
@@ -1867,7 +1865,6 @@
nesdev->int_req &= ~NES_INT_TIMER;
nes_write32(nesdev->regs + NES_INTF_INT_MASK, ~(nesdev->intf_int_req));
nes_write32(nesdev->regs+NES_INT_MASK, ~nesdev->int_req);
- nesdev->nesadapter->tune_timer.timer_in_use_old = 0;
} else {
nes_write32(nesdev->regs+NES_INT_MASK, 0x0000ffff|(~nesdev->int_req));
}
diff --git a/drivers/infiniband/hw/nes/nes_hw.h b/drivers/infiniband/hw/nes/nes_hw.h
index 1e10df5..b7e2844 100644
--- a/drivers/infiniband/hw/nes/nes_hw.h
+++ b/drivers/infiniband/hw/nes/nes_hw.h
@@ -962,7 +962,7 @@
#define DEFAULT_JUMBO_NES_QL_LOW 12
#define DEFAULT_JUMBO_NES_QL_TARGET 40
#define DEFAULT_JUMBO_NES_QL_HIGH 128
-#define NES_NIC_CQ_DOWNWARD_TREND 8
+#define NES_NIC_CQ_DOWNWARD_TREND 16
struct nes_hw_tune_timer {
//u16 cq_count;