Thanks a lot, This(http://lxr.linux.no/linux+v2.6.36/Documentation/ia64/IRQ-redir.txt) should be the next step after finding the solution for the first problem (that is just using core0) !!! :D I found something which is quite related (http://www.alexonlinux.com/smp-affinity-and-proper-interrupt-handling-in-li nux ) this article says that it may not be possible to change irq mask in the systems with CONFIG_HOTPLUG_CPU enabled! Now I have 3 problems: 1) I cannot find out the relationship between CONFIG_HOTPLUG_CPU and irq affinity. 2) I only have problem with eth0 and eth1 ( for example for the timer interrupt I can change the mask and it is effective! Although it only uses the first enabled core in the mask, which is related to IA64 feature) 3) I don`t know how to disable CONFIG_HOTPLUG_CPU ! If you can help me with solving any of these problems I would really appreciate it :) Regards, RSH -----Original Message----- From: Mulyadi Santosa [mailto:mulyadi.santosa@xxxxxxxxx] Sent: Tuesday, November 30, 2010 10:56 AM To: Raoufehsadat Hashemian Harandi Cc: kernelnewbies@xxxxxxxxxxxx Subject: Re: FW: problem setting up affinity mask for irq intrupt On Wed, Dec 1, 2010 at 00:39, Raoufehsadat Hashemian Harandi <rhashem@xxxxxxxxxxx> wrote: > Yes, it is running, I also putted a heavy load with around 10000 interrupt > per second to see if it changes the number but the output is still like > this: may we see the content of /etc/sysconfig/irqbalance? who knows, there is a clue there... > The interesting point is that the value of affinity mask changes frequently, > when I set it to FFFFFFFF it is FF for some seconds and then it changes to > other values like 02 04 08 ! huh? dynamically changing affinity? weird... BTW, please kindly check http://lxr.linux.no/linux+v2.6.36/Documentation/ia64/IRQ-redir.txt, perhaps it would give another clue for your case PS: right now, IMHO, putting aside the "fact" that your affinitiy mask could change automatically somehow, I am guessing that the irq is handled that way due to some internal calculation. To make it short, I read somewhere that by sticking interrupt to a CPU core, it actually speed up response. of course, this is not always true for every situation, but kernel does exactly that at the first place. Also, by doing that, per cpu cache hotness would likely be maintained. Interrupt handler always running, L1/L2/L3 cache is effectively utilized....everybody happy :D -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
