On Wed, Apr 11, 2007 at 11:16:41AM +1000, Michael Ellerman wrote:
> On Tue, 2007-04-10 at 11:59 -0500, Milton Miller wrote:
> >
> > This means we are doing population counts of two masks, when we really
> > just care that they are the same. How about using
> > cpus_equal(cpu_online_mask, cpu_present_mask)?
>
> Yep that's sensible.
>
> > This shows how close these two functions are. The difference is
> > what happens when cpus_empty is true -- we default in one and
> > ignore in the other.
> >
> > How about adding another arg to get_server, that says to fail
> > or default for the empty case, with failure being -1?
> >
> > I'll try to code this up, but it might be a day or two until i get
> > the time.
I modified the patch based on suggestions given by Milton and Mike.
Milton is this patch okay?
Tested on 2.6.21-rc7.
=====
It is observed that in some PPC970 based machines, When the kernel is
booted with maxcpus=1, interrupts were distributed to non online cpus
also. So a condition is included to check whether the cpu online
map and cpu present map are equal or not. If they are equal
default_distrib_server is used as the interrupt server otherwise
default_server(ie boot cpu) is used as the interrupt server.
In addition to this, if an interrupt is assigned to a specific cpu (ie
smp affinity) and if that cpu is not online, the earlier code used to
return the default_distrib_server as interrupt server. This patch
introduces an additional parameter to the get_irq function ie
strict_check, based on this parameter, if the cpu is not online either
default_distrib_server or -1 is returned.
Cc: Milton Miller <[EMAIL PROTECTED]>,
Michael Ellerman <[EMAIL PROTECTED]>
Signed-off-by: Mohan Kumar M <[EMAIL PROTECTED]>
---
arch/powerpc/platforms/pseries/xics.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
Index: linux-2.6.21-rc4/arch/powerpc/platforms/pseries/xics.c
===================================================================
--- linux-2.6.21-rc4.orig/arch/powerpc/platforms/pseries/xics.c
+++ linux-2.6.21-rc4/arch/powerpc/platforms/pseries/xics.c
@@ -156,9 +156,9 @@ static inline void lpar_qirr_info(int n_
#ifdef CONFIG_SMP
-static int get_irq_server(unsigned int virq)
+static int get_irq_server(unsigned int virq, unsigned int strict_check)
{
- unsigned int server;
+ int server;
/* For the moment only implement delivery to all cpus or one cpu */
cpumask_t cpumask = irq_desc[virq].affinity;
cpumask_t tmp = CPU_MASK_NONE;
@@ -167,21 +167,25 @@ static int get_irq_server(unsigned int v
return default_server;
if (cpus_equal(cpumask, CPU_MASK_ALL)) {
- server = default_distrib_server;
+ if (cpus_equal(cpu_online_map, cpu_present_map))
+ server = default_distrib_server;
+ else
+ server = default_server;
} else {
cpus_and(tmp, cpu_online_map, cpumask);
- if (cpus_empty(tmp))
+ if (cpus_empty(tmp) && !strict_check)
server = default_distrib_server;
+ else if(cpus_empty(tmp) && strict_check)
+ server = -1;
else
server = get_hard_smp_processor_id(first_cpu(tmp));
}
return server;
-
}
#else
-static int get_irq_server(unsigned int virq)
+static int get_irq_server(unsigned int virq, unsigned int strict_check)
{
return default_server;
}
@@ -192,7 +196,7 @@ static void xics_unmask_irq(unsigned int
{
unsigned int irq;
int call_status;
- unsigned int server;
+ int server;
pr_debug("xics: unmask virq %d\n", virq);
@@ -201,7 +205,7 @@ static void xics_unmask_irq(unsigned int
if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
return;
- server = get_irq_server(virq);
+ server = get_irq_server(virq, 0);
call_status = rtas_call(ibm_set_xive, 3, 1, NULL, irq, server,
DEFAULT_PRIORITY);
@@ -415,7 +419,10 @@ static void xics_set_affinity(unsigned i
/* For the moment only implement delivery to all cpus or one cpu */
if (cpus_equal(cpumask, CPU_MASK_ALL)) {
- newmask = default_distrib_server;
+ if (cpus_equal(cpu_online_map, cpu_present_map))
+ newmask = default_distrib_server;
+ else
+ newmask = default_server;
} else {
cpus_and(tmp, cpu_online_map, cpumask);
if (cpus_empty(tmp))
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