[Gdb] Hardware watchpoints on gnu/Linux on pentium4

[Greg Lindberg]

I'm having trouble getting watch points to work.  I have a multi-threaded
cpp program that has something walking through memory writing what looks
like memory addresses.  I have an address that I can trap on that gets
reliably overwritten.  When I use the watch command:
 watch address
or 
 watch (int) address
gdb uses software watching not the hardware registers available on the 
pentium4.  If I create a global pointer to int, and put an address that gets
overwritten into it and use the watch command.
 watch *pointVar
gdb says that it is using a hardware watch point but I never get a break.
I have printouts in my code that display the area that is getting overwritten
and I can see that the address that the watch point is set to is overwritten
but gdb doesn't break.  Also, as a test, I tried updating the pointer 
variable in my code to see is I was misunderstanding the way watchpoints
work, but that did not trigger the watchpoint either.

Can anyone explain to me what I doing wrong so that I can get the watch
point to work correctly?  By the way I have tried a (char) watch also
just in case the writes are not being done as words.

Thanks in advance.

Greg Lindberg