Re: voluntary-preempt-2.6.8.1-P9 : big latency when logging on console

[P.O. Gaillard]

Ingo Molnar wrote:
> * P.O. Gaillard <pierre-olivier.gaillard@xxxxxxxxxxxxxxxxxx> wrote:
>
>
> > Hello,
> >
> > I have a 1.6ms latency every time I log in with P9.
>
>
> could you try the patch below, ontop of P9? (or ontop of the latest, -Q5
> patch)
>
> The problem with font loading is that vt_ioctl runs with the BKL held
> (as all ioctls) which disables preemption, but in this case it seems
> pretty safe to drop the lock - the vga console has its own spinlock.
Thank you very much. I had to add a "#include <linux/smp_lock.h>" at the start 
of vga_con.c to get it to compile and then :
1) I can login on the console without getting any latency above 100 microseconds.
2) Nothing seems to be broken by your change.

Note: I tested on 2.6.8.1 + P9.

	thanks !

	Pierre-Olivier


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