Andi Kleen wrote:
-#ifdef CONFIG_S390
-#ifdef CONFIG_MATHEMU
-       {
-               .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
-               .procname       = "ieee_emulation_warnings",
-               .data           = &sysctl_ieee_emulation_warnings,
-               .maxlen         = sizeof(int),
-               .mode           = 0644,
-               .proc_handler   = &proc_dointvec,
-       },

I think there needs to be a way to have this syctl only
when it's really implemented for the paravirt ops.

Alright, lets drop that part of the patch for now. Here's an update. Please apply.

I suppose you should move it to dynamic registration on demand.

And start working on this.

Zach
Fix the VMI-Timer no-idle-hz code.

Do not setup a one shot alarm if we are keeping the periodic alarm
armed.  Additionally, since the periodic alarm can be run at a lower
rate than HZ, let's fixup the guard to the no-idle-hz mode appropriately.
This fixes the bug where the no-idle-hz mode might have a higher interrupt
rate than the non-idle case.

Signed-off-by: Dan Hecht <[EMAIL PROTECTED]>
Signed-off-by: Zachary Amsden <[EMAIL PROTECTED]>

diff -r 9d107b81bb7d arch/i386/kernel/vmitime.c
--- a/arch/i386/kernel/vmitime.c        Thu Feb 01 23:43:37 2007 -0800
+++ b/arch/i386/kernel/vmitime.c        Thu Feb 01 23:52:59 2007 -0800
@@ -374,7 +374,6 @@ int vmi_stop_hz_timer(void)
        unsigned long seq, next;
        unsigned long long real_cycles_expiry;
        int cpu = smp_processor_id();
-       int idle;
 
        BUG_ON(!irqs_disabled());
        if (sysctl_hz_timer != 0)
@@ -382,13 +381,13 @@ int vmi_stop_hz_timer(void)
 
        cpu_set(cpu, nohz_cpu_mask);
        smp_mb();
+
        if (rcu_needs_cpu(cpu) || local_softirq_pending() ||
-           (next = next_timer_interrupt(), time_before_eq(next, jiffies))) {
+           (next = next_timer_interrupt(), 
+            time_before_eq(next, jiffies + HZ/CONFIG_VMI_ALARM_HZ))) {
                cpu_clear(cpu, nohz_cpu_mask);
-               next = jiffies;
-               idle = 0;
-       } else
-               idle = 1;
+               return 0;
+       }
 
        /* Convert jiffies to the real cycle counter. */
        do {
@@ -398,17 +397,13 @@ int vmi_stop_hz_timer(void)
        } while (read_seqretry(&xtime_lock, seq));
 
        /* This cpu is going idle. Disable the periodic alarm. */
-       if (idle) {
-               vmi_timer_ops.cancel_alarm(VMI_CYCLES_AVAILABLE);
-               per_cpu(idle_start_jiffies, cpu) = jiffies;
-       }
-
+       vmi_timer_ops.cancel_alarm(VMI_CYCLES_AVAILABLE);
+       per_cpu(idle_start_jiffies, cpu) = jiffies;
        /* Set the real time alarm to expire at the next event. */
        vmi_timer_ops.set_alarm(
-                     VMI_ALARM_WIRING | VMI_ALARM_IS_ONESHOT | VMI_CYCLES_REAL,
-                     real_cycles_expiry, 0);
-
-       return idle;
+               VMI_ALARM_WIRING | VMI_ALARM_IS_ONESHOT | VMI_CYCLES_REAL,
+               real_cycles_expiry, 0);
+       return 1;
 }
 
 static void vmi_reenable_hz_timer(int cpu)

Reply via email to