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authorJeff Kirsher <jeffrey.t.kirsher@intel.com>2012-04-20 08:51:45 +0000
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2012-04-24 22:45:35 -0700
commit727c356f4d799b53f94cf8fe43e19d64482348c7 (patch)
tree6593d0cf2299e0cc6e2ca42274ff2a40cd49517b /drivers/net/ethernet/intel/e1000e/param.c
parent569a3aff70e880588fe4b3f1622ac60abbeb4a28 (diff)
downloadlinux-727c356f4d799b53f94cf8fe43e19d64482348c7.tar.bz2
e1000e: Fix default interrupt throttle rate not set in NIC HW
Based on the original patch from Ying Cai <ycai@google.com> This change ensures that the itr/itr_setting adjustment logic is used, even for the default/compiled-in value. Context: When we changed the default InterruptThrottleRate value from default (3 = dynamic mode) to 8000 for example, only adapter->itr_setting (which controls interrupt coalescing mode) was set to 8000, but adapter->itr (which controls the value set in NIC register) was not updated accordingly. So from ethtool, it seemed the interrupt throttling is enabled at 8000 intr/s, but the NIC actually was running in dynamic mode which has lower CPU efficiency especially when throughput is not high. CC: Ying Cai <ycai@google.com> CC: David Decotigny <david.decotigny@google.com> Signed-off-by: Jeff Kirsher <jeffrey.kirsher@intel.com> Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Diffstat (limited to 'drivers/net/ethernet/intel/e1000e/param.c')
-rw-r--r--drivers/net/ethernet/intel/e1000e/param.c99
1 files changed, 53 insertions, 46 deletions
diff --git a/drivers/net/ethernet/intel/e1000e/param.c b/drivers/net/ethernet/intel/e1000e/param.c
index ff796e42c3eb..16adeb9418a8 100644
--- a/drivers/net/ethernet/intel/e1000e/param.c
+++ b/drivers/net/ethernet/intel/e1000e/param.c
@@ -106,7 +106,7 @@ E1000_PARAM(RxAbsIntDelay, "Receive Absolute Interrupt Delay");
/*
* Interrupt Throttle Rate (interrupts/sec)
*
- * Valid Range: 100-100000 (0=off, 1=dynamic, 3=dynamic conservative)
+ * Valid Range: 100-100000 or one of: 0=off, 1=dynamic, 3=dynamic conservative
*/
E1000_PARAM(InterruptThrottleRate, "Interrupt Throttling Rate");
#define DEFAULT_ITR 3
@@ -344,53 +344,60 @@ void __devinit e1000e_check_options(struct e1000_adapter *adapter)
if (num_InterruptThrottleRate > bd) {
adapter->itr = InterruptThrottleRate[bd];
- switch (adapter->itr) {
- case 0:
- e_info("%s turned off\n", opt.name);
- break;
- case 1:
- e_info("%s set to dynamic mode\n", opt.name);
- adapter->itr_setting = adapter->itr;
- adapter->itr = 20000;
- break;
- case 3:
- e_info("%s set to dynamic conservative mode\n",
- opt.name);
- adapter->itr_setting = adapter->itr;
- adapter->itr = 20000;
- break;
- case 4:
- e_info("%s set to simplified (2000-8000 ints) "
- "mode\n", opt.name);
- adapter->itr_setting = 4;
- break;
- default:
- /*
- * Save the setting, because the dynamic bits
- * change itr.
- */
- if (e1000_validate_option(&adapter->itr, &opt,
- adapter) &&
- (adapter->itr == 3)) {
- /*
- * In case of invalid user value,
- * default to conservative mode.
- */
- adapter->itr_setting = adapter->itr;
- adapter->itr = 20000;
- } else {
- /*
- * Clear the lower two bits because
- * they are used as control.
- */
- adapter->itr_setting =
- adapter->itr & ~3;
- }
- break;
- }
+
+ /*
+ * Make sure a message is printed for non-special
+ * values. And in case of an invalid option, display
+ * warning, use default and got through itr/itr_setting
+ * adjustment logic below
+ */
+ if ((adapter->itr > 4) &&
+ e1000_validate_option(&adapter->itr, &opt, adapter))
+ adapter->itr = opt.def;
} else {
- adapter->itr_setting = opt.def;
+ /*
+ * If no option specified, use default value and go
+ * through the logic below to adjust itr/itr_setting
+ */
+ adapter->itr = opt.def;
+
+ /*
+ * Make sure a message is printed for non-special
+ * default values
+ */
+ if (adapter->itr > 40)
+ e_info("%s set to default %d\n", opt.name,
+ adapter->itr);
+ }
+
+ adapter->itr_setting = adapter->itr;
+ switch (adapter->itr) {
+ case 0:
+ e_info("%s turned off\n", opt.name);
+ break;
+ case 1:
+ e_info("%s set to dynamic mode\n", opt.name);
+ adapter->itr = 20000;
+ break;
+ case 3:
+ e_info("%s set to dynamic conservative mode\n",
+ opt.name);
adapter->itr = 20000;
+ break;
+ case 4:
+ e_info("%s set to simplified (2000-8000 ints) mode\n",
+ opt.name);
+ break;
+ default:
+ /*
+ * Save the setting, because the dynamic bits
+ * change itr.
+ *
+ * Clear the lower two bits because
+ * they are used as control.
+ */
+ adapter->itr_setting &= ~3;
+ break;
}
}
{ /* Interrupt Mode */