Re: RFC: IRQ affinity (aka interrupt routing)

[Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>]

Hi rmind,

(2014/07/27 1:18), Mindaugas Rasiukevicius wrote:
> Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost> wrote:
> > The implementation is consist of following three pathes:
> > <...>
> >      (2) new kernfs file to show interrupt numbers per cpu
> >          "vmstat -i" cannot show interrupt numbers per cpu. So I
> >          implement new kernfs file to show per cpu. The usage is "cat
> >          /kern/interrupts". For example, we can see below output
> >          which is like linux's /proc/interrupts
> >          ====================
> >           IRQ      CPU#00          CPU#01
> >             1           0*              0
> >             3           0*              0
> >             4           0*              0
> >             6           0*              0
> >             7           0*              0
> >             9           0*              0
> >            12           0*              0
> >            14           0*              0
> >            15           0*              0
> >            16         108*              0
> >            17     1193055*              0
> >            18      680358             150*
> >          ====================
> >          "*" mean the cpu is routed the IRQ number interrupts.
> >              
> > https://github.com/knakahara/netbsd-src/commit/dc7c17dd2f0cd78a03983849feb8fdd8cbe0d9c6
>
> Agree with Martin that vmstat -i could grow per-CPU counters, but it might
> be a bit more work than you want to do.  So, up to you. :)

I consider vmstat -i grow per-CPU counters after implementing intrctl(8).
It is no problem to change the output format of vmstat -i, doesn't it?

> > <...>
> >
> > Above implementation works well, but I think the UI is not so good.
> > So, I am going to implement new command intrctl(8). The usage is consist
> > of below two sub command.
> >      (A) "intrctl list"
> >          This sub command show interrupt numbers per cpu (like
> >          /kern/interrupts).
> >
> >      (B) "intrctl -i 18 -c 1"
> >          This sub command let interrupts route other cpu. "18" is IRQ
> >          number, "1" is cpuid (like "sysctl -w kern.cpu_affinity.irq=18:1").
> >
> > Could you comment which UI is good, current "sysctl and /kern/interrupts"
> > or new "intrctl"?
>
> I do not really like /kern/interrupts.  intrctl(8) seems like a good
> interface.  Note that cpuctl(8) has intr/nointr commands which are not
> enabled at this moment.  They should move to intrctl(8).

intrctl(8) gain agreements with two developers, and It seems to gain more
agreements, maybe. So I approach to implement intrctl(8). Yes, you told
me the cpuctl(8) sub command at previous meeting :) I move cpuctl intr/
nointr sub comamnd to intrctl(8).


Thanks,

--
//////////////////////////////////////////////////////////////////////
Internet Initiative Japan Inc.

Device Engineering Section,
Core Product Development Department,
Product Division,
Technology Unit

Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>