# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1261554838 0
# Node ID 6b0f9559fbd5c6e04c10c18953a77a41a0464440
# Parent fc6ca854775c70d502aa0c9ad0dcfc07977e0ea9
Replace process_pending_timers() with process_pending_softirqs().
This ensures that any critical softirqs are handled in a timely manner
(e.g., TIME_CALIBRATE_SOFTIRQ) while still avoiding being preempted by
the scheduler (by SCHEDULE_SOFTIRQ), which is the reason for avoiding
use of do_softirq() directly.
Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
xen-unstable changeset: 20714:a60f508548a8
xen-unstable date: Tue Dec 22 18:35:34 2009 +0000
---
xen/arch/x86/acpi/cpu_idle.c | 2 +-
xen/arch/x86/domain_build.c | 6 +++---
xen/arch/x86/smpboot.c | 4 ++--
xen/common/page_alloc.c | 2 +-
xen/common/softirq.c | 16 ++++++++++++++--
xen/common/timer.c | 9 ---------
xen/drivers/char/console.c | 2 +-
xen/include/xen/softirq.h | 7 +++++++
xen/include/xen/timer.h | 6 ------
9 files changed, 29 insertions(+), 25 deletions(-)
diff -r fc6ca854775c -r 6b0f9559fbd5 xen/arch/x86/acpi/cpu_idle.c
--- a/xen/arch/x86/acpi/cpu_idle.c Tue Dec 22 11:37:27 2009 +0000
+++ b/xen/arch/x86/acpi/cpu_idle.c Wed Dec 23 07:53:58 2009 +0000
@@ -201,7 +201,7 @@ static void acpi_processor_idle(void)
sched_tick_suspend();
/* sched_tick_suspend() can raise TIMER_SOFTIRQ. Process it now. */
- process_pending_timers();
+ process_pending_softirqs();
/*
* Interrupts must be disabled during bus mastering calculations and
diff -r fc6ca854775c -r 6b0f9559fbd5 xen/arch/x86/domain_build.c
--- a/xen/arch/x86/domain_build.c Tue Dec 22 11:37:27 2009 +0000
+++ b/xen/arch/x86/domain_build.c Wed Dec 23 07:53:58 2009 +0000
@@ -878,7 +878,7 @@ int __init construct_dom0(
((unsigned int *)vphysmap_start)[pfn] = mfn;
set_gpfn_from_mfn(mfn, pfn);
if (!(pfn & 0xfffff))
- process_pending_timers();
+ process_pending_softirqs();
}
si->first_p2m_pfn = pfn;
si->nr_p2m_frames = d->tot_pages - count;
@@ -898,7 +898,7 @@ int __init construct_dom0(
++alloc_epfn;
#endif
if (!(pfn & 0xfffff))
- process_pending_timers();
+ process_pending_softirqs();
}
}
BUG_ON(pfn != d->tot_pages);
@@ -920,7 +920,7 @@ int __init construct_dom0(
#undef pfn
page++; pfn++;
if (!(pfn & 0xfffff))
- process_pending_timers();
+ process_pending_softirqs();
}
}
diff -r fc6ca854775c -r 6b0f9559fbd5 xen/arch/x86/smpboot.c
--- a/xen/arch/x86/smpboot.c Tue Dec 22 11:37:27 2009 +0000
+++ b/xen/arch/x86/smpboot.c Wed Dec 23 07:53:58 2009 +0000
@@ -1305,7 +1305,7 @@ void __cpu_die(unsigned int cpu)
}
mdelay(100);
mb();
- process_pending_timers();
+ process_pending_softirqs();
if ((++i % 10) == 0)
printk(KERN_ERR "CPU %u still not dead...\n", cpu);
}
@@ -1470,7 +1470,7 @@ int __devinit __cpu_up(unsigned int cpu)
cpu_set(cpu, smp_commenced_mask);
while (!cpu_isset(cpu, cpu_online_map)) {
mb();
- process_pending_timers();
+ process_pending_softirqs();
}
cpufreq_add_cpu(cpu);
diff -r fc6ca854775c -r 6b0f9559fbd5 xen/common/page_alloc.c
--- a/xen/common/page_alloc.c Tue Dec 22 11:37:27 2009 +0000
+++ b/xen/common/page_alloc.c Wed Dec 23 07:53:58 2009 +0000
@@ -945,7 +945,7 @@ void __init scrub_heap_pages(void)
for ( mfn = first_valid_mfn; mfn < max_page; mfn++ )
{
- process_pending_timers();
+ process_pending_softirqs();
/* Quick lock-free check. */
if ( allocated_in_map(mfn) )
diff -r fc6ca854775c -r 6b0f9559fbd5 xen/common/softirq.c
--- a/xen/common/softirq.c Tue Dec 22 11:37:27 2009 +0000
+++ b/xen/common/softirq.c Wed Dec 23 07:53:58 2009 +0000
@@ -22,7 +22,7 @@ irq_cpustat_t irq_stat[NR_CPUS];
static softirq_handler softirq_handlers[NR_SOFTIRQS];
-asmlinkage void do_softirq(void)
+static void __do_softirq(unsigned long ignore_mask)
{
unsigned int i, cpu;
unsigned long pending;
@@ -38,13 +38,25 @@ asmlinkage void do_softirq(void)
if ( rcu_pending(cpu) )
rcu_check_callbacks(cpu);
- if ( (pending = softirq_pending(cpu)) == 0 )
+ if ( (pending = (softirq_pending(cpu) & ~ignore_mask)) == 0 )
break;
i = find_first_set_bit(pending);
clear_bit(i, &softirq_pending(cpu));
(*softirq_handlers[i])();
}
+}
+
+void process_pending_softirqs(void)
+{
+ ASSERT(!in_irq() && local_irq_is_enabled());
+ /* Do not enter scheduler as it can preempt the calling context. */
+ __do_softirq(1ul<<SCHEDULE_SOFTIRQ);
+}
+
+asmlinkage void do_softirq(void)
+{
+ __do_softirq(0);
}
void open_softirq(int nr, softirq_handler handler)
diff -r fc6ca854775c -r 6b0f9559fbd5 xen/common/timer.c
--- a/xen/common/timer.c Tue Dec 22 11:37:27 2009 +0000
+++ b/xen/common/timer.c Wed Dec 23 07:53:58 2009 +0000
@@ -464,15 +464,6 @@ static void timer_softirq_action(void)
spin_unlock_irq(&ts->lock);
}
-
-void process_pending_timers(void)
-{
- unsigned int cpu = smp_processor_id();
- ASSERT(!in_irq() && local_irq_is_enabled());
- if ( test_and_clear_bit(TIMER_SOFTIRQ, &softirq_pending(cpu)) )
- timer_softirq_action();
-}
-
s_time_t align_timer(s_time_t firsttick, uint64_t period)
{
if ( !period )
diff -r fc6ca854775c -r 6b0f9559fbd5 xen/drivers/char/console.c
--- a/xen/drivers/char/console.c Tue Dec 22 11:37:27 2009 +0000
+++ b/xen/drivers/char/console.c Wed Dec 23 07:53:58 2009 +0000
@@ -657,7 +657,7 @@ void __init console_endboot(void)
printk("%d... ", 3-i);
for ( j = 0; j < 100; j++ )
{
- process_pending_timers();
+ process_pending_softirqs();
mdelay(10);
}
}
diff -r fc6ca854775c -r 6b0f9559fbd5 xen/include/xen/softirq.h
--- a/xen/include/xen/softirq.h Tue Dec 22 11:37:27 2009 +0000
+++ b/xen/include/xen/softirq.h Wed Dec 23 07:53:58 2009 +0000
@@ -54,6 +54,13 @@ static inline void raise_softirq(unsigne
}
/*
+ * Process pending softirqs on this CPU. This should be called periodically
+ * when performing work that prevents softirqs from running in a timely manner.
+ * Use this instead of do_softirq() when you do not want to be preempted.
+ */
+void process_pending_softirqs(void);
+
+/*
* TASKLETS -- dynamically-allocatable tasks run in softirq context
* on at most one CPU at a time.
*/
diff -r fc6ca854775c -r 6b0f9559fbd5 xen/include/xen/timer.h
--- a/xen/include/xen/timer.h Tue Dec 22 11:37:27 2009 +0000
+++ b/xen/include/xen/timer.h Wed Dec 23 07:53:58 2009 +0000
@@ -103,12 +103,6 @@ extern void kill_timer(struct timer *tim
extern void kill_timer(struct timer *timer);
/*
- * Process pending timers on this CPU. This should be called periodically
- * when performing work that prevents softirqs from running in a timely manner.
- */
-extern void process_pending_timers(void);
-
-/*
* Bootstrap initialisation. Must be called before any other timer function.
*/
extern void timer_init(void);
_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog
|
Home