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

P.O. Gaillard
2004-08-30T12:25:56Z

Ingo Molnar wrote:
> * P.O. Gaillard <pierre-olivier.gaillard@fr.thalesgroup.com> 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