# HG changeset patch
# User Jimi Xenidis <[EMAIL PROTECTED]>
# Node ID 6af601c5ebe192a0de72430cdd94da5ba46ff287
# Parent 20bd3b7b7519e01f7b6bfa97c7a655e1dc027f5d
[XEN][POWERPC] workaround for context_switch() bug
We have a bug in that if we switch domains in schedule() we switch
right away regardless of whatever else is pending. This means that
if the timer goes off while in schedule(), the next domain will be
preempted by the interval defined below. So until we fix our
cotnext_switch(), the follow workaround will make sure that the
domain we switch to does not run for to long so we can continue to
service the other timers in the timer queue and that the value is
long enough to escape this particular timer event.
Signed-off-by: Jimi Xenidis <[EMAIL PROTECTED]>
---
xen/arch/powerpc/exceptions.c | 19 +++++++++++++++++--
1 files changed, 17 insertions(+), 2 deletions(-)
diff -r 20bd3b7b7519 -r 6af601c5ebe1 xen/arch/powerpc/exceptions.c
--- a/xen/arch/powerpc/exceptions.c Fri Dec 15 08:16:56 2006 -0500
+++ b/xen/arch/powerpc/exceptions.c Fri Dec 15 08:36:03 2006 -0500
@@ -35,7 +35,9 @@ extern ulong ppc_do_softirq(ulong orig_m
extern ulong ppc_do_softirq(ulong orig_msr);
extern void do_timer(struct cpu_user_regs *regs);
extern void do_dec(struct cpu_user_regs *regs);
-extern void program_exception(struct cpu_user_regs *regs, unsigned long
cookie);
+extern void program_exception(struct cpu_user_regs *regs,
+ unsigned long cookie);
+extern int reprogram_timer(s_time_t timeout);
int hdec_sample = 0;
@@ -43,7 +45,20 @@ void do_timer(struct cpu_user_regs *regs
{
/* Set HDEC high so it stops firing and can be reprogrammed by
* set_preempt() */
- mthdec(INT_MAX);
+ /* FIXME! HACK ALERT!
+ *
+ * We have a bug in that if we switch domains in schedule() we
+ * switch right away regardless of whatever else is pending. This
+ * means that if the timer goes off while in schedule(), the next
+ * domain will be preempted by the interval defined below. So
+ * until we fix our cotnext_switch(), the follow workaround will
+ * make sure that the domain we switch to does not run for to long
+ * so we can continue to service the other timers in the timer
+ * queue and that the value is long enough to escape this
+ * particular timer event.
+ */
+ reprogram_timer(NOW() + MILLISECS(1));
+
raise_softirq(TIMER_SOFTIRQ);
}
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