Rusty Russell wrote:
This isn't on stack, so it isn't buying us anything.
It's the CONFIG_NR_CPUS=4096 but nr_cpu_ids=4 case which we win using
dynamic allocation. Gotta love distribution kernels.
What does it buy? 4096/8 = 512 bytes statically allocated?
I understand passing things as pointers, but allocating everything
dynamically is unCish.
Is the plan to drop cpumask_t?
Yes. And undefine 'struct cpumask' if CONFIG_CPUMASK_OFFSTACK. That
will stop assignment and on-stack declarations for all but the most
determined.
If so, we're penalizing non-stack users
by forcing them to go through another pointer (and cacheline).
Not quite. If !CONFIG_CPUMASK_OFFSTACK, cpumask_var_t == cpumask_t[1].
Blame Linus :)
Hm, is there a C trick which will error out when allocating something on
the stack, but work when allocating statically? I can think of
something to do the reverse, but that doesn't help.
Maybe a weak or visibility attribute? These don't make sense on
function locals.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
