Commit 9a40bddd authored by Chris Wilson's avatar Chris Wilson

drm/i915/gt: Expose heartbeat interval via sysfs

We monitor the health of the system via periodic heartbeat pulses. The
pulses also provide the opportunity to perform garbage collection.
However, we interpret an incomplete pulse (a missed heartbeat) as an
indication that the system is no longer responsive, i.e. hung, and
perform an engine or full GPU reset. Given that the preemption
granularity can be very coarse on a system, we let the sysadmin override
our legacy timeouts which were "optimised" for desktop applications.

The heartbeat interval can be adjusted per-engine using,

	/sys/class/drm/card?/engine/*/heartbeat_interval_ms
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarSteve Carbonari <steven.carbonari@intel.com>
Tested-by: default avatarSteve Carbonari <steven.carbonari@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200228131716.3243616-7-chris@chris-wilson.co.uk
parent db3d8338
...@@ -20,6 +20,9 @@ config DRM_I915_HEARTBEAT_INTERVAL ...@@ -20,6 +20,9 @@ config DRM_I915_HEARTBEAT_INTERVAL
check the health of the GPU and undertake regular house-keeping of check the health of the GPU and undertake regular house-keeping of
internal driver state. internal driver state.
This is adjustable via
/sys/class/drm/card?/engine/*/heartbeat_interval_ms
May be 0 to disable heartbeats and therefore disable automatic GPU May be 0 to disable heartbeats and therefore disable automatic GPU
hang detection. hang detection.
......
...@@ -8,6 +8,7 @@ ...@@ -8,6 +8,7 @@
#include "i915_drv.h" #include "i915_drv.h"
#include "intel_engine.h" #include "intel_engine.h"
#include "intel_engine_heartbeat.h"
#include "sysfs_engines.h" #include "sysfs_engines.h"
struct kobj_engine { struct kobj_engine {
...@@ -315,6 +316,49 @@ preempt_timeout_show(struct kobject *kobj, struct kobj_attribute *attr, ...@@ -315,6 +316,49 @@ preempt_timeout_show(struct kobject *kobj, struct kobj_attribute *attr,
static struct kobj_attribute preempt_timeout_attr = static struct kobj_attribute preempt_timeout_attr =
__ATTR(preempt_timeout_ms, 0644, preempt_timeout_show, preempt_timeout_store); __ATTR(preempt_timeout_ms, 0644, preempt_timeout_show, preempt_timeout_store);
static ssize_t
heartbeat_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t count)
{
struct intel_engine_cs *engine = kobj_to_engine(kobj);
unsigned long long delay;
int err;
/*
* We monitor the health of the system via periodic heartbeat pulses.
* The pulses also provide the opportunity to perform garbage
* collection. However, we interpret an incomplete pulse (a missed
* heartbeat) as an indication that the system is no longer responsive,
* i.e. hung, and perform an engine or full GPU reset. Given that the
* preemption granularity can be very coarse on a system, the optimal
* value for any workload is unknowable!
*/
err = kstrtoull(buf, 0, &delay);
if (err)
return err;
if (delay >= jiffies_to_msecs(MAX_SCHEDULE_TIMEOUT))
return -EINVAL;
err = intel_engine_set_heartbeat(engine, delay);
if (err)
return err;
return count;
}
static ssize_t
heartbeat_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
struct intel_engine_cs *engine = kobj_to_engine(kobj);
return sprintf(buf, "%lu\n", engine->props.heartbeat_interval_ms);
}
static struct kobj_attribute heartbeat_interval_attr =
__ATTR(heartbeat_interval_ms, 0644, heartbeat_show, heartbeat_store);
static void kobj_engine_release(struct kobject *kobj) static void kobj_engine_release(struct kobject *kobj)
{ {
kfree(kobj); kfree(kobj);
...@@ -357,6 +401,9 @@ void intel_engines_add_sysfs(struct drm_i915_private *i915) ...@@ -357,6 +401,9 @@ void intel_engines_add_sysfs(struct drm_i915_private *i915)
&all_caps_attr.attr, &all_caps_attr.attr,
&max_spin_attr.attr, &max_spin_attr.attr,
&stop_timeout_attr.attr, &stop_timeout_attr.attr,
#if CONFIG_DRM_I915_HEARTBEAT_INTERVAL
&heartbeat_interval_attr.attr,
#endif
NULL NULL
}; };
......
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