[E1000-devel] igb and IntMode & irq_balance issue

[March, A. M <agu...@in...>]

Hi 
    I am having some issues with the ibg driver (1.2.22)  and Intel
Corp. 82575EB Gigabit Network attached to Intel Corp. 82801I (ICH9
Family) PCI Express on RedHat 2.6.18-53.el5 x86_64 arch.  

 I am working with HPC equipment, I need to disable the Interruption, so
I set the InterruptThrottleRate parameter to 0,0 in order to disable.
However, the Interrupt seems to be not fully disabled. For instance,

1- if I left the InterruptThrottleRate as defult and irq balance on  ---
the latency is ~60uSeg
2- if I set the InterruptThrottleRate to O,O  irq balance on  --- the
latency is ~29uSeg

3- if I set the InterruptThrottleRate to O,O and IntMode=0,0 irq balance
off --- the latency is ~20uSeg
4- if I set the InterruptThrottleRate to O,O and IntMode=1,1 irq balance
off --- the latency is ~18uSeg

Could some one explain me what could be happening? It is correct to
modify the IntMode and the Irqbalance to switch to off for this king of
chipset?
Please, any comment will be a great help to us

 
filename:       /lib/modules/2.6.18-53.el5/kernel/drivers/net/igb/igb.ko
version:        1.2.22
license:        GPL
description:    Intel(R) Gigabit Ethernet Network Driver
author:         Intel Corporation, <e10...@li...>
srcversion:     3453E88A6E046972DD03154
alias:          pci:v00008086d000010D6sv*sd*bc*sc*i*
alias:          pci:v00008086d000010A9sv*sd*bc*sc*i*
alias:          pci:v00008086d000010A7sv*sd*bc*sc*i*
depends:
vermagic:       2.6.18-53.el5 SMP mod_unload gcc-4.1
parm:           InterruptThrottleRate:Interrupt Throttling Rate (array
of int)
parm:           IntMode:Interrupt Mode (array of int)
parm:           LLIPort:Low Latency Interrupt TCP Port (array of int)
parm:           LLIPush:Low Latency Interrupt on TCP Push flag (array of
int)
parm:           LLISize:Low Latency Interrupt on Packet Size (array of
int)
parm:           debug:Debug level (0=none, ..., 16=all) (int)
Kernel Parameter
ro root=LABEL=/ pci=msi console=ttyS1,115200
..
Regards,





 
Agustin March <mailto:agu...@in...> 
Argentina Distributing Computing Solution 
+54 351 5265618
Intel Argentina S.A.