On Mon, 2016-12-12 at 23:31 +1000, Nicholas Piggin wrote: > On Mon, 12 Dec 2016 20:50:03 +1100 > Balbir Singh <bsinghar...@gmail.com> wrote: > > > This patch removes the disabling of interrupts > > in soft-disable mode, when interrupts are received > > (in lazy mode). The new scheme keeps the interrupts > > enabled when we receive an interrupt and does the > > following > > > > a. On decrementer interrupt, instead of setting > > dec to maximum and returning, we do the following > > i. Call a function handle_nmi_dec, which in > > turn calls handle_soft_nmi > > ii. handle_soft_nmi sets the decrementer value > > to 1 second and checks if more than 30 > > seconds have passed since starting it. If > > so it calls BUG_ON(1), we can do an NMI > > panic as well. > > b. When an external interrupt is received, we > > store the interrupt in local_paca via > > ppc_md.get_irq(). Later when interrupts are > > enabled and replayed, we reuse the stored > > interrupt and process it via generic_handle_irq > > This seems pretty good. My NMI handler should plug in just > the same to the masked decrementer, so that wouldn't be a > problem.
Thats good to know, I believe so as well. <snip> > > while soft-disable */ > > + u32 irq; /* IRQ pending */ > > u8 nap_state_lost; /* NV GPR values lost in > > power7_idle */ > > u64 sprg_vdso; /* Saved user- > > visible sprg */ > > Can you avoid some padding if you move it to below irq_happened? > Will do > > +EXC_COMMON(handle_nmi_dec, 0x900, handle_soft_nmi) > > +EXC_COMMON(elevate_save_irq, 0x500, handle_elevated_irq) > > I wonder if the name should match the type of interrupt rather than > implementation detail (elevated?), and match the existing handlers > e.g, hardware_interrupt_masked common handler could call > do_IRQ_masked. > Sure, will rename them > As for the NMI, I would prefer just to keep it out of the timer path > completely and schedule a Linux timer for it as I had. > > Otherwise, this looks nice if it does the right thing with the > interrupt > controller. It hasn't taken a lot of lines to implement which is very > cool. > Yep, although the code works for PPC_XICS only which is good for now. When we do XIVE, we can add more bits Balbir
