On Thu, Apr 03, 2003 at 11:55:37PM +1000, Keith Owens wrote: > On Thu, 3 Apr 2003 14:16:07 +0530, > "Vamsi Krishna S ." <[EMAIL PROTECTED]> wrote: > >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. > > I suggest you wait a bit. A lot of the breakpoint problems come from > the fact that kdb tries to control who can enter kdb, in particular the > way kdb tries to avoid two cpus entering kdb at the same time. I have > concluded that this design was wrong, there are some situations where > kdb cannot prevent concurrent entry, e.g. external debugging interrupts > that are sent to all cpus and cannot be blocked. As usual, ia64 is a > special case :(. > > The answer is not to try to prevent concurrent entry to kdb but to > accept that it occurs and work with it. That means the breakpoint > state must become per-cpu, as in the smphdr* patches. Concurrent > software breakpoints will be allowed. > Ok. For software breakpoints, when user types "bc *", this means you have to remove the INT3 instruction from the last CPU that is leaving KDB. I will take a look at the next release.
Thanks, Vamsi. -- Vamsi Krishna S. Linux Technology Center, IBM Software Lab, Bangalore. Ph: +91 80 5044959 Internet: [EMAIL PROTECTED]
