@@ -114,6 +114,24 @@ i915_gem_context_clear_user_engines(struct i915_gem_context *ctx)
clear_bit(CONTEXT_USER_ENGINES, &ctx->flags);
}
+static inline bool
+i915_gem_context_nopreempt(const struct i915_gem_context *ctx)
+{
+ return test_bit(CONTEXT_NOPREEMPT, &ctx->flags);
+}
+
+static inline void
+i915_gem_context_set_nopreempt(struct i915_gem_context *ctx)
+{
+ set_bit(CONTEXT_NOPREEMPT, &ctx->flags);
+}
+
+static inline void
+i915_gem_context_clear_nopreempt(struct i915_gem_context *ctx)
+{
+ clear_bit(CONTEXT_NOPREEMPT, &ctx->flags);
+}
+
static inline bool i915_gem_context_is_kernel(struct i915_gem_context *ctx)
{
return !ctx->file_priv;
@@ -146,6 +146,7 @@ struct i915_gem_context {
#define CONTEXT_CLOSED 1
#define CONTEXT_FORCE_SINGLE_SUBMISSION 2
#define CONTEXT_USER_ENGINES 3
+#define CONTEXT_NOPREEMPT 4
struct mutex mutex;
@@ -2077,6 +2077,9 @@ static int eb_submit(struct i915_execbuffer *eb)
if (err)
return err;
+ if (i915_gem_context_nopreempt(eb->gem_context))
+ eb->request->flags |= I915_REQUEST_NOPREEMPT;
+
return 0;
}
@@ -344,6 +344,8 @@ static const struct i915_oa_format gen8_plus_oa_formats[I915_OA_FORMAT_MAX] = {
* struct perf_open_properties - for validated properties given to open a stream
* @sample_flags: `DRM_I915_PERF_PROP_SAMPLE_*` properties are tracked as flags
* @single_context: Whether a single or all gpu contexts should be monitored
+ * @hold_preemption: Whether the preemption is disabled for the filtered
+ * context
* @ctx_handle: A gem ctx handle for use with @single_context
* @metrics_set: An ID for an OA unit metric set advertised via sysfs
* @oa_format: An OA unit HW report format
@@ -359,6 +361,7 @@ struct perf_open_properties {
u32 sample_flags;
u64 single_context:1;
+ u64 hold_preemption:1;
u64 ctx_handle;
/* OA sampling state */
@@ -2512,6 +2515,8 @@ static int i915_oa_stream_init(struct i915_perf_stream *stream,
if (WARN_ON(stream->oa_buffer.format_size == 0))
return -EINVAL;
+ stream->hold_preemption = props->hold_preemption;
+
stream->oa_buffer.format =
perf->oa_formats[props->oa_format].format;
@@ -2832,6 +2837,9 @@ static void i915_perf_enable_locked(struct i915_perf_stream *stream)
if (stream->ops->enable)
stream->ops->enable(stream);
+
+ if (stream->hold_preemption)
+ i915_gem_context_set_nopreempt(stream->ctx);
}
/**
@@ -2856,6 +2864,9 @@ static void i915_perf_disable_locked(struct i915_perf_stream *stream)
/* Allow stream->ops->disable() to refer to this */
stream->enabled = false;
+ if (stream->hold_preemption)
+ i915_gem_context_clear_nopreempt(stream->ctx);
+
if (stream->ops->disable)
stream->ops->disable(stream);
}
@@ -3053,6 +3064,15 @@ i915_perf_open_ioctl_locked(struct i915_perf *perf,
}
}
+ if (props->hold_preemption) {
+ if (!props->single_context) {
+ DRM_DEBUG("preemption disable with no context\n");
+ ret = -EINVAL;
+ goto err;
+ }
+ privileged_op = true;
+ }
+
/*
* On Haswell the OA unit supports clock gating off for a specific
* context and in this mode there's no visibility of metrics for the
@@ -3067,7 +3087,7 @@ i915_perf_open_ioctl_locked(struct i915_perf *perf,
* MI_REPORT_PERF_COUNT commands and so consider it a privileged op to
* enable the OA unit by default.
*/
- if (IS_HASWELL(perf->i915) && specific_ctx)
+ if (IS_HASWELL(perf->i915) && specific_ctx && !props->hold_preemption)
privileged_op = false;
/* Similar to perf's kernel.perf_paranoid_cpu sysctl option
@@ -3077,7 +3097,7 @@ i915_perf_open_ioctl_locked(struct i915_perf *perf,
*/
if (privileged_op &&
i915_perf_stream_paranoid && !capable(CAP_SYS_ADMIN)) {
- DRM_DEBUG("Insufficient privileges to open system-wide i915 perf stream\n");
+ DRM_DEBUG("Insufficient privileges to open i915 perf stream\n");
ret = -EACCES;
goto err_ctx;
}
@@ -3279,6 +3299,9 @@ static int read_properties_unlocked(struct i915_perf *perf,
props->oa_periodic = true;
props->oa_period_exponent = value;
break;
+ case DRM_I915_PERF_PROP_HOLD_PREEMPTION:
+ props->hold_preemption = !!value;
+ break;
case DRM_I915_PERF_PROP_MAX:
MISSING_CASE(id);
return -EINVAL;
@@ -4051,8 +4074,13 @@ int i915_perf_ioctl_version(void)
*
* 2: Added runtime modification of OA config.
* I915_PERF_IOCTL_CONFIG
+ *
+ * 3: Add DRM_I915_PERF_PROP_HOLD_PREEMPTION parameter to hold
+ * preemption on a particular context so that performance data is
+ * accessible from a delta of MI_RPC reports without looking at the
+ * OA buffer.
*/
- return 2;
+ return 3;
}
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
@@ -170,6 +170,14 @@ struct i915_perf_stream {
*/
bool enabled;
+ /*8
+ * @hold_preemption: Whether preemption is put on hold for command
+ * submissions done on the @ctx. This is useful for some drivers that
+ * cannot easily post process the OA buffer context to subtract delta
+ * of performance counters not associated with @ctx.
+ */
+ bool hold_preemption;
+
/**
* @ops: The callbacks providing the implementation of this specific
* type of configured stream.
@@ -1890,6 +1890,17 @@ enum drm_i915_perf_property_id {
*/
DRM_I915_PERF_PROP_OA_EXPONENT,
+ /**
+ * Specifying this property is only valid when specify a context to
+ * filter with DRM_I915_PERF_PROP_CTX_HANDLE. Specifying this property
+ * will hold preemption of the particular context we want to gather
+ * performance data about. The execbuf2 submissions must include a
+ * drm_i915_gem_execbuffer_ext_perf parameter for this to apply.
+ *
+ * This property is available in perf revision 3.
+ */
+ DRM_I915_PERF_PROP_HOLD_PREEMPTION,
+
DRM_I915_PERF_PROP_MAX /* non-ABI */
};