** Reply to message from "Petr Vandrovec" <VANDROVE@vc.cvut.cz> on Tue, 19 Jun
2001 01:36:26 MET-1
> No. Another CPU might increment value between LOCK INCL and
> fetching v->counter. On ia32 architecture you are almost out of
> luck. You can either try building atomic_inc around CMPXCHG,
> using it as conditional store (but CMPXCHG is not available
> on i386), or you can just guard your atomic variable with
> spinlock - but in that case there is no reason for using atomic_t
> at all.
Oh, I see the problem. You could do something like this:
cli
mov %0, %%eax
inc %%eax
mov %%eax, %0
sti
and then return eax, but that won't work on SMP (whereas the "lock inc" does).
Doing a global cli might work, though.
-- Timur Tabi - ttabi@interactivesi.com Interactive Silicon - http://www.interactivesi.com- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sat Jun 23 2001 - 21:00:24 EST