Hi Dipankar,
> The tasklet code also needs fixing. It is a miracle that the kernel
> booted when I tested that code. Here is a fixed diff.
:) I was surprised it worked with the missing spin_unlock too. Im
testing the fixed diff now, so far it looks good.
> I am curious about performance of smptimers. It seems that
> webserver benchmark performance worsens with smptimers (Ingo version)
> contrary to our expectations. Do you see this ? If so, could this
> happen because -
>
> 1) Bouncing around of global_bh_lock cacheline by more cpus compared
> to earlier timer implemenation ?
> 2) All per-cpu timers invoked from timer_bh running in one cpu ?
>
> Do you see any other side-effects of smptimers ?
We used to see bad behaviour. It turned out to be the per cpu
timer interrupt firing at exactly the same time on all cpus. One
cpu would successfully spin_trylock and the others would fail
and postpone the work.
We now evenly space the per cpu interrupts. Does intel do the same?
> Also, did my PPC changes for smptimers work or you had to fix it ?
I tested ppc64 and it worked fine.
Anton
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This archive was generated by hypermail 2b29 : Thu May 23 2002 - 22:00:19 EST