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Re: [PATCH 2.6 8/8] RDMA/nes: Fix interrupt moderation low threshold

Previous thread: [PATCH 2.6 7/8] RDMA/nes: Fix rdma connection establishment on big-endian platforms by gstreiff on Thursday, February 21, 2008 - 7:31 am. (1 message)

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From: gstreiff
Subject: [PATCH 2.6 8/8] RDMA/nes: Fix interrupt moderation low threshold
Date: Thursday, February 21, 2008 - 7:34 am

From: John Lacombe <jlacombe@neteffect.com>

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>

---
 drivers/infiniband/hw/nes/nes_hw.c |   12 ++++--------
 drivers/infiniband/hw/nes/nes_hw.h |    2 +-
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/infiniband/hw/nes/nes_hw.c b/drivers/infiniband/hw/nes/nes_hw.c
index 7c4c0fb..6b677b5 100644
--- a/drivers/infiniband/hw/nes/nes_hw.c
+++ b/drivers/infiniband/hw/nes/nes_hw.c
@@ -156,15 +156,13 @@ static void nes_nic_tune_timer(struct nes_device *nesdev)
 
 	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 +1726,6 @@ int nes_napi_isr(struct nes_device *nesdev)
 			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 +1864,6 ...
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[view original message]
From: Roland Dreier
Subject: Re: [PATCH 2.6 8/8] RDMA/nes: Fix interrupt moderation low threshold
Date: Monday, February 25, 2008 - 4:57 pm

thanks, applied all 8 patches
--


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Previous thread: [PATCH 2.6 7/8] RDMA/nes: Fix rdma connection establishment on big-endian platforms by gstreiff on Thursday, February 21, 2008 - 7:31 am. (1 message)

Next thread: [PATCH] macb: Fix speed setting by Atsushi Nemoto on Thursday, February 21, 2008 - 6:50 am. (10 messages)