Re: [PATCH] IB/ehca: Serialize HCA-related hCalls on POWER5

On Thursday 06 December 2007, Roland Dreier wrote:

=A0> Regarding the performance problem, have you checked whether converti=

ng all

=A0> your spin_lock_irqsave to spin_lock/spin_lock_irq improves your perf=

ormance

=A0> on the older machines? Maybe it's already fast enough that way.
=20
It does seem that the only places that the hcall_lock is taken also
use msleep, so they must always be in process context. =A0So you can
safely just use spin_lock(), right?

I think it needs some more inspection. The msleep in there is only called
for hcalls that return H_IS_LONG_BUSY(). In theory, you can call
ehca_plpar_hcall_norets() from inside an interrupt handler if the
hcall in question never returns long busy.

	Arnd <><