Re: [Xen-ia64-devel] [PATCH] pal_halt_light emulate for domU TAKE3

[Isaku Yamahata <yamahata@xxxxxxxxxxxxx>]

Calling migrate_timer from context_switch() seems to introduce
unnecessary overhead.
Why did you choose to insert migrate_timer() to context_switch()
instead of inserting it ot the following position?

diff -r 8c6bb45901e7 xen/arch/ia64/xen/hypercall.c
--- a/xen/arch/ia64/xen/hypercall.c     Wed Aug 16 14:28:57 2006 -0600
+++ b/xen/arch/ia64/xen/hypercall.c     Mon Aug 21 13:46:05 2006 +0900
@@ -233,7 +233,10 @@ fw_hypercall (struct pt_regs *regs)
                        }
                        else {
                                perfc_incrc(pal_halt_light);
-                               do_sched_op_compat(SCHEDOP_yield, 0);
    <<<<<<<<<<<<< migrate_timer() >>>>>>>>>>>>>>>>>>>>>>>>>>>
+                               set_timer(&v->arch.hlt_timer,
+                                       vcpu_get_next_timer_ns(v));
+                               do_sched_op_compat(SCHEDOP_block, 0);
+                               stop_timer(&v->arch.hlt_timer);
                        }
                        regs->r8 = 0;
                        regs->r9 = 0;


On Wed, Aug 23, 2006 at 07:29:11PM +0900, Atsushi SAKAI wrote:
> Hi, Isaku
> 
> Sorry for confusing.
> It should replace from "for context_switch" to "to context_switch"
> migrate_timer is in context_switch.
> 
> Thanks
> Atsushi 
> 
> >Hi Atsushi.
> >
> >On Wed, Aug 23, 2006 at 05:48:15PM +0900, Atsushi SAKAI wrote:
> >
> >> 1)migrate_timer for hlt_timer_fn is added for context_switch
> >>   This makes correct pCPU work for timer.
> >
> >Is it necessary to call migrate_timer() every context switch 
> >instead of calling it right before set_timer(&hlt_timer)?
> >
> >-- 
> >yamahata
> >
> 
> 
> 
> 
> 
> 
> 
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> Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-ia64-devel

-- 
yamahata

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