Yes, that is what I thought. My earlier patch fixed only the int3
points. I will do similar fix for debugreg breakpoints too
and update the man pages and code comments accordingly.
Thanks,
Vamsi.
On Thu, Apr 03, 2003 at 03:20:01PM +0800, Zhang, Sonic wrote:
> Hi,
>
> Yes, the case you mentioned is possible in current KDB. I remember some
> related instructions in the KDB man pages. It is said that don't remove any
> break point when you enter KDB through DEBUG trap or Int3 trap, disable it
> instead and remove it safely later when you enter KDB via keyboard trap or
> serial port trap.
>
> Maybe your patch can clean up these comments in the man pages?
>
> Regards.
>
> Sonic Zhang
>
> -----Original Message-----
> From: Vamsi Krishna S . [mailto:vamsi@xxxxxxxxxx]
> Sent: 2003?4?3? 14:59
> To: Zhang, Sonic
> Cc: Keith Owens; Hua Qin; kdb@xxxxxxxxxxx
> Subject: Re: [PATCH] kdb on SMP (breakpoint hits multiple cpus simultaneously)
>
>
> Hi,
>
> Thanks for the clarification. I thought from my quick
> glance through that currently all hard breakpoints
> are global, whereas your patches enabled per-cpu
> breakpoints. On second look, you are right, the current
> code allows only per-cpu debugreg-breakpoints, global
> ones are much more generally useful, which your patch
> enables.
>
> I also agree with the name changes and the fact that
> per-cpu breakpoints may be useful for debugging certain
> paths (processes) bound to a specific cpu.
>
> smphdr* patches are very much needed.
>
> Thanks,
> Vamsi.
>
> BTW: Can you think about what happens if two debugreg
> breakpoints are triggered at about the same time on
> different cpus? One of them wins the race to enter
> the kdb, and then the user clears all breakpoints..
> will kdb be able still recognise this as one of its
> breakpoints? I think not, but can you give it a thought?
>
> --
> Vamsi Krishna S.
> Linux Technology Center,
> IBM Software Lab, Bangalore.
> Ph: +91 80 5044959
> Internet: vamsi@xxxxxxxxxx
--
Vamsi Krishna S.
Linux Technology Center,
IBM Software Lab, Bangalore.
Ph: +91 80 5044959
Internet: vamsi@xxxxxxxxxx
|