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authorJuergen Gross <jgross@suse.com>2021-02-19 16:40:28 +0100
committerBoris Ostrovsky <boris.ostrovsky@oracle.com>2021-02-23 17:07:11 +0100
commit06f45fe96fcd81531b0bcb2a6115da563ae6dbd6 (patch)
treee0004c9548d4612288b71f5fd541eab54fc63ead /drivers/xen/events
parentMerge tag 'nfsd-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/... (diff)
downloadlinux-06f45fe96fcd81531b0bcb2a6115da563ae6dbd6.tar.xz
linux-06f45fe96fcd81531b0bcb2a6115da563ae6dbd6.zip
xen/events: add per-xenbus device event statistics and settings
Add syfs nodes for each xenbus device showing event statistics (number of events and spurious events, number of associated event channels) and for setting a spurious event threshold in case a frontend is sending too many events without being rogue on purpose. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20210219154030.10892-7-jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Diffstat (limited to 'drivers/xen/events')
-rw-r--r--drivers/xen/events/events_base.c27
1 files changed, 25 insertions, 2 deletions
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index b249f2d6b0cc..adb7260e94b2 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -323,6 +323,8 @@ static int xen_irq_info_evtchn_setup(unsigned irq,
ret = xen_irq_info_common_setup(info, irq, IRQT_EVTCHN, evtchn, 0);
info->u.interdomain = dev;
+ if (dev)
+ atomic_inc(&dev->event_channels);
return ret;
}
@@ -568,18 +570,28 @@ static void xen_irq_lateeoi_locked(struct irq_info *info, bool spurious)
return;
if (spurious) {
+ struct xenbus_device *dev = info->u.interdomain;
+ unsigned int threshold = 1;
+
+ if (dev && dev->spurious_threshold)
+ threshold = dev->spurious_threshold;
+
if ((1 << info->spurious_cnt) < (HZ << 2)) {
if (info->spurious_cnt != 0xFF)
info->spurious_cnt++;
}
- if (info->spurious_cnt > 1) {
- delay = 1 << (info->spurious_cnt - 2);
+ if (info->spurious_cnt > threshold) {
+ delay = 1 << (info->spurious_cnt - 1 - threshold);
if (delay > HZ)
delay = HZ;
if (!info->eoi_time)
info->eoi_cpu = smp_processor_id();
info->eoi_time = get_jiffies_64() + delay;
+ if (dev)
+ atomic_add(delay, &dev->jiffies_eoi_delayed);
}
+ if (dev)
+ atomic_inc(&dev->spurious_events);
} else {
info->spurious_cnt = 0;
}
@@ -908,6 +920,7 @@ static void __unbind_from_irq(unsigned int irq)
if (VALID_EVTCHN(evtchn)) {
unsigned int cpu = cpu_from_irq(irq);
+ struct xenbus_device *dev;
xen_evtchn_close(evtchn);
@@ -918,6 +931,11 @@ static void __unbind_from_irq(unsigned int irq)
case IRQT_IPI:
per_cpu(ipi_to_irq, cpu)[ipi_from_irq(irq)] = -1;
break;
+ case IRQT_EVTCHN:
+ dev = info->u.interdomain;
+ if (dev)
+ atomic_dec(&dev->event_channels);
+ break;
default:
break;
}
@@ -1581,6 +1599,7 @@ void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl)
{
int irq;
struct irq_info *info;
+ struct xenbus_device *dev;
irq = get_evtchn_to_irq(port);
if (irq == -1)
@@ -1610,6 +1629,10 @@ void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl)
info = info_for_irq(irq);
+ dev = (info->type == IRQT_EVTCHN) ? info->u.interdomain : NULL;
+ if (dev)
+ atomic_inc(&dev->events);
+
if (ctrl->defer_eoi) {
info->eoi_cpu = smp_processor_id();
info->irq_epoch = __this_cpu_read(irq_epoch);