On Mon, 2017-06-05 at 20:21 +1000, Michael Ellerman wrote: > On Thu, 2017-03-16 at 08:55:45 UTC, Christophe Leroy wrote: > > It often happens to have simultaneous interrupts, for instance > > when having double Ethernet attachment. With the current > > implementation, we suffer the cost of kernel entry/exit for each > > interrupt. > > > > This patch introduces a loop in __do_irq() to handle all interrupts > > at once before returning. > > > > Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr> > > Applied to powerpc next, thanks. > > https://git.kernel.org/powerpc/c/45cb08f4791ce6a15c54598b4cb73d
Hrm, I hadn't noticed that patch... We used to do that and then removed the code for it. There's a cost, sometimes noticeable, to an extra call to ppc_md.get_irq. Why not have your get_irq (or eoi) implementation set a per-cpu requesting a new spin of the loop ? We could move the xive force replay stuff to use the same thing. Ben.