Messages in this thread |  | | Date | Wed, 3 Oct 2018 17:07:36 +1000 | From | Nicholas Piggin <> | Subject | Re: [RFC PATCH v3 4/7] powerpc: regain entire stack space |
| |
On Wed, 3 Oct 2018 08:45:25 +0200 Christophe LEROY <christophe.leroy@c-s.fr> wrote:
> Le 03/10/2018 à 08:30, Nicholas Piggin a écrit : > > On Wed, 3 Oct 2018 07:52:59 +0200 > > Christophe LEROY <christophe.leroy@c-s.fr> wrote: > > > >> Le 03/10/2018 à 07:34, Nicholas Piggin a écrit : > >>> On Mon, 1 Oct 2018 12:30:25 +0000 (UTC) > >>> Christophe Leroy <christophe.leroy@c-s.fr> wrote: > >>> > >>>> thread_info is not anymore in the stack, so the entire stack > >>>> can now be used. > >>> > >>> Nice. > >>> > >>>> > >>>> In the meantime, all pointers to the stacks are not anymore > >>>> pointers to thread_info so this patch changes them to void* > >>> > >>> Wasn't this previously effectively already the case with patch > >>> 3/7? You had thread_info sized space left there, but it was not > >>> used or initialized right? Does it make sense to move this part > >>> of it to the previous patch? > >> > >> Not really. > >> > >> In 3/7 I changed the prototypes of two functions that really used the > >> pointer as a task pointer only. > > I meant 2/7 here sorry. > > >> > >> Here it change things that before 4/7 were really used as both stack > >> pointers and thread_info pointers. > > And here I meant 3/7 > > > > > What uses it as a thread_info pointer? It seems more like a stack > > with some amount of unused space in it but that's all. > > Before 3/7, we have > > void do_softirq_own_stack(void) > { > struct thread_info *curtp, *irqtp; > > curtp = current_thread_info(); > irqtp = softirq_ctx[smp_processor_id()]; > irqtp->task = curtp->task; > irqtp->flags = 0; > call_do_softirq(irqtp); > irqtp->task = NULL; > > /* Set any flag that may have been set on the > * alternate stack > */ > if (irqtp->flags) > set_bits(irqtp->flags, &curtp->flags); > } > > After 3/7, we have > > void do_softirq_own_stack(void) > { > struct thread_info *irqtp; > > irqtp = softirq_ctx[smp_processor_id()]; > call_do_softirq(irqtp); > } > > > So now only we can change irqtp to void* can't we ?
In patch 3 we can, right? That's what I mean by moving from thread_info * to void * in patch 3 rather than 4.
But if you prefer not to, it's fine. Maybe it keeps patch 3 a little smaller.
Thanks, Nick
|  |