Messages in this thread |  | | Date | Sat, 22 Sep 2001 23:33:10 +0200 | From | Andrea Arcangeli <> | Subject | Re: ksoftirqd? (Was: Re: [PATCH] Preemption Latency Measurement Tool) |
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On Sat, Sep 22, 2001 at 10:51:16PM +0200, Roger Larsson wrote: > On Saturday 22 September 2001 15.14, Andrea Arcangeli wrote: > > On Sat, Sep 22, 2001 at 02:56:58PM +0200, Roger Larsson wrote: > > > Hi, > > > > > > We have a new kid on the block since we started thinking of a preemptive > > > kernel. > > > > > > ksoftirqd... > > > > > > Running with nice 19 (shouldn't it really be -19?) > > I repeat this question - should it be nice 19 and not nice -19 (not nice)?
Being it +19 it is light with respect to the other tasks in the system, mainly considering there's one for each cpu.
> Sep 22 22:37:38 jeloin logger: *** ./stress_dbench begin *** > Sep 22 22:37:42 jeloin kernel: ksoftirqd: do_softirq > Sep 22 22:37:44 jeloin last message repeated 2 times > Sep 22 22:37:48 jeloin kernel: Latency 8ms PID 7 %% kupdated > Sep 22 22:37:49 jeloin kernel: ksoftirqd: do_softirq > Sep 22 22:38:19 jeloin last message repeated 18 times > Sep 22 22:38:20 jeloin su: (to root) roger on /dev/pts/2 > Sep 22 22:38:20 jeloin PAM-unix2[988]: session started for user root, service > su > Sep 22 22:38:23 jeloin kernel: ksoftirqd: do_softirq > Sep 22 22:38:24 jeloin modprobe: modprobe: Can't locate module net-pf-10 > Sep 22 22:38:24 jeloin kernel: ksoftirqd: do_softirq > Sep 22 22:38:58 jeloin last message repeated 20 times > Sep 22 22:39:05 jeloin last message repeated 4 times > Sep 22 22:42:03 jeloin kernel: ksoftirqd: do_softirq > Sep 22 22:43:58 jeloin logger: *** ./stress_dbench end ***
one reschedule every few seconds sounds ok.
> Possibly but the other case is quite common too...
if you try to put a printk also in do_softirq you'll see why it is not the common case :)
also you may want to put the printk in the schedule() path, ksoftirqd may just be rescheduled once, and run many of the do_softirq().
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