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authorJesse Brandeburg <jesse.brandeburg@intel.com>2010-05-05 02:26:03 +0400
committerDavid S. Miller <davem@davemloft.net>2010-05-06 08:15:32 +0400
commiteab2abf5826b78b126826cc70e564c44816396da (patch)
treef771389b55090767e8aecdc36f3e80019b3b60bf /drivers/net/e1000/e1000_main.c
parentedf15c17420fed108046da50b3d3ae53dfa0e0ae (diff)
downloadlinux-eab2abf5826b78b126826cc70e564c44816396da.tar.xz
e1000/e1000e: implement a simple interrupt moderation
Back before e1000-7.3.20, the e1000 driver had a simple algorithm that managed interrupt moderation. The driver was updated in 7.3.20 to have the new "adaptive" interrupt moderation but we have customer requests to redeploy the old way as an option. This patch adds the old functionality back. The new functionality can be enabled via module parameter or at runtime via ethtool. Module parameter: (InterruptThrottleRate=4) to use this new moderation method. Ethtool method: ethtool -C ethX rx-usecs 4 Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/e1000/e1000_main.c')
-rw-r--r--drivers/net/e1000/e1000_main.c18
1 files changed, 17 insertions, 1 deletions
diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index e6ebc222459f..4dd2c23775cb 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -31,7 +31,7 @@
char e1000_driver_name[] = "e1000";
static char e1000_driver_string[] = "Intel(R) PRO/1000 Network Driver";
-#define DRV_VERSION "7.3.21-k5-NAPI"
+#define DRV_VERSION "7.3.21-k6-NAPI"
const char e1000_driver_version[] = DRV_VERSION;
static const char e1000_copyright[] = "Copyright (c) 1999-2006 Intel Corporation.";
@@ -2386,6 +2386,22 @@ link_up:
}
}
+ /* Simple mode for Interrupt Throttle Rate (ITR) */
+ if (hw->mac_type >= e1000_82540 && adapter->itr_setting == 4) {
+ /*
+ * Symmetric Tx/Rx gets a reduced ITR=2000;
+ * Total asymmetrical Tx or Rx gets ITR=8000;
+ * everyone else is between 2000-8000.
+ */
+ u32 goc = (adapter->gotcl + adapter->gorcl) / 10000;
+ u32 dif = (adapter->gotcl > adapter->gorcl ?
+ adapter->gotcl - adapter->gorcl :
+ adapter->gorcl - adapter->gotcl) / 10000;
+ u32 itr = goc > 0 ? (dif * 6000 / goc + 2000) : 8000;
+
+ ew32(ITR, 1000000000 / (itr * 256));
+ }
+
/* Cause software interrupt to ensure rx ring is cleaned */
ew32(ICS, E1000_ICS_RXDMT0);