diff options
| -rw-r--r-- | drivers/gpu/drm/i915/Kconfig.profile | 3 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/gt/sysfs_engines.c | 46 |
2 files changed, 49 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/Kconfig.profile b/drivers/gpu/drm/i915/Kconfig.profile index c280b6ae38eb..d8d4a16179bd 100644 --- a/drivers/gpu/drm/i915/Kconfig.profile +++ b/drivers/gpu/drm/i915/Kconfig.profile @@ -73,4 +73,7 @@ config DRM_I915_TIMESLICE_DURATION is scheduled for execution for the timeslice duration, before switching to the next context. + This is adjustable via + /sys/class/drm/card?/engine/*/timeslice_duration_ms + May be 0 to disable timeslicing. diff --git a/drivers/gpu/drm/i915/gt/sysfs_engines.c b/drivers/gpu/drm/i915/gt/sysfs_engines.c index 81b5c90df5fc..53402edbf98a 100644 --- a/drivers/gpu/drm/i915/gt/sysfs_engines.c +++ b/drivers/gpu/drm/i915/gt/sysfs_engines.c @@ -142,6 +142,48 @@ all_caps_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) static struct kobj_attribute all_caps_attr = __ATTR(known_capabilities, 0444, all_caps_show, NULL); +static ssize_t +timeslice_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 duration; + int err; + + /* + * Execlists uses a scheduling quantum (a timeslice) to alternate + * execution between ready-to-run contexts of equal priority. This + * ensures that all users (though only if they of equal importance) + * have the opportunity to run and prevents livelocks where contexts + * may have implicit ordering due to userspace semaphores. + */ + + err = kstrtoull(buf, 0, &duration); + if (err) + return err; + + if (duration > jiffies_to_msecs(MAX_SCHEDULE_TIMEOUT)) + return -EINVAL; + + WRITE_ONCE(engine->props.timeslice_duration_ms, duration); + + if (execlists_active(&engine->execlists)) + set_timer_ms(&engine->execlists.timer, duration); + + return count; +} + +static ssize_t +timeslice_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.timeslice_duration_ms); +} + +static struct kobj_attribute timeslice_duration_attr = +__ATTR(timeslice_duration_ms, 0644, timeslice_show, timeslice_store); + static void kobj_engine_release(struct kobject *kobj) { kfree(kobj); @@ -203,6 +245,10 @@ void intel_engines_add_sysfs(struct drm_i915_private *i915) if (sysfs_create_files(kobj, files)) goto err_object; + if (intel_engine_has_timeslices(engine) && + sysfs_create_file(kobj, ×lice_duration_attr.attr)) + goto err_engine; + if (0) { err_object: kobject_put(kobj); |