Hi, On 8/3/06, Thomas Petazzoni <thomas.petazzoni@xxxxxxxx> wrote:
Hi, Le Wed, 2 Aug 2006 11:41:54 +0530, "Ranjan Sinha" <rnjn.sinha@xxxxxxxxx> a écrit : > "The purpose of irqbalance is distribute hardware interrupts across > processors on a multiprocessor system in order to increase > performance. It is useful mostly just > for 2.4 kernels, or 2.6 kernels with CONFIG_IRQBALANCE turned off." > > I tried this on another dual XEON processor machine(kernel 2.6.13). On > this machine I can see from /proc/interrupts that interrupts are > distributed on both processors. But irqbalance is _not_ running on > this second machine. The kernel config file is almost same as on my > dual core machine. I am confused now. Maybe you've hit a kernel bug ? Can you try with the latest 2.6.17 release ? And eventually with 2.6.18-rcX ?
Just to recapture everything on this thread, I have a Dell Laptop that is running on dual core T2400 but from /proc/interirupts I can see that the interrupt count on CPU1 is 0. I tried to test this with the latest 2.6.17.7 kernel. The kernel config file has the following entries CONFIG_IRQBALANCE=y CONFIG_X86_GOOD_APIC=y CONFIG_X86_INTEL_USERCOPY=y CONFIG_X86_USE_PPRO_CHECKSUM=y CONFIG_X86_TSC=y CONFIG_HPET_TIMER=y CONFIG_HPET_EMULATE_RTC=y CONFIG_NR_CPUS=2 CONFIG_SCHED_SMT=y CONFIG_SCHED_MC=y # CONFIG_PREEMPT_NONE is not set CONFIG_PREEMPT_VOLUNTARY=y # CONFIG_PREEMPT is not set CONFIG_PREEMPT_BKL=y CONFIG_X86_LOCAL_APIC=y CONFIG_X86_IO_APIC=y I understand that there is a new option _CONFIG_SCHED_MC_ in this version, probably for better scheduling on multi core CPUS. However, in spite of this still /proc/interrupts show that all interrupts are delivered to CPU0. On installing irqbalance again, some of the interrupts are delivered on CPU1 as well, notable exception is eth0 (Broadcom NetXtremeII card). Is there something fundamental in the hardware itself? - Thanks and regards, Ranjan -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
