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RDMA/nes: Fix interrupt moderation low threshold

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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>
This commit is contained in:
John Lacombe 2008-02-21 08:34:58 -06:00 committed by Roland Dreier
parent 30da7cff87
commit 4b1cc7e7ca
2 changed files with 6 additions and 9 deletions
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13
drivers/infiniband/hw/nes/nes_hw.c
View File

@ -156,15 +156,14 @@ 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 +1727,6 @@ 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 +1865,6 @@ void nes_dpc(unsigned long param)
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));
}

2
drivers/infiniband/hw/nes/nes_hw.h
View File

@ -962,7 +962,7 @@ struct nes_arp_entry {
#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;