pm_rps: Add variable load support to load helper

The load helper can be set to HIGH or LOW. HIGH is the original mode
of sending continuous dword store commands. LOW adds a pause between
each command to reduce throughput.

Signed-off-by: Jeff McGee <jeff.mcgee@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/tests/pm_rps.c b/tests/pm_rps.c
index 9277196..05b859c 100644 (file)
--- a/tests/pm_rps.c
+++ b/tests/pm_rps.c
@@ -146,6 +146,11 @@ static void dumpit(const int *freqs)
 #define dump(x) if (verbose) dumpit(x)
 #define log(...) if (verbose) printf(__VA_ARGS__)
 
+enum load {
+       LOW,
+       HIGH
+};
+
 static struct load_helper {
        int devid;
        int has_ppgtt;
@@ -153,13 +158,17 @@ static struct load_helper {
        struct intel_batchbuffer *batch;
        drm_intel_bo *target_buffer;
        bool ready;
+       enum load load;
        bool exit;
        struct igt_helper_process igt_proc;
 } lh;
 
 static void load_helper_signal_handler(int sig)
 {
-       lh.exit = true;
+       if (sig == SIGUSR2)
+               lh.load = lh.load == LOW ? HIGH : LOW;
+       else
+               lh.exit = true;
 }
 
 static void emit_store_dword_imm(uint32_t val)
@@ -190,21 +199,30 @@ static void emit_store_dword_imm(uint32_t val)
        }
 }
 
-static void load_helper_run(void)
+#define LOAD_HELPER_PAUSE_USEC 500
+static void load_helper_run(enum load load)
 {
        assert(!lh.igt_proc.running);
 
        igt_require(lh.ready == true);
 
+       lh.load = load;
+
        igt_fork_helper(&lh.igt_proc) {
                uint32_t val = 0;
 
                signal(SIGUSR1, load_helper_signal_handler);
+               signal(SIGUSR2, load_helper_signal_handler);
 
                while (!lh.exit) {
                        emit_store_dword_imm(val);
                        intel_batchbuffer_flush_on_ring(lh.batch, 0);
                        val++;
+
+                       /* Lower the load by pausing after every submitted
+                        * write. */
+                       if (lh.load == LOW)
+                               usleep(LOAD_HELPER_PAUSE_USEC);
                }
 
                /* Map buffer to stall for write completion */
@@ -215,6 +233,17 @@ static void load_helper_run(void)
        }
 }
 
+static void load_helper_set_load(enum load load)
+{
+       assert(lh.igt_proc.running);
+
+       if (lh.load == load)
+               return;
+
+       lh.load = load;
+       kill(lh.igt_proc.pid, SIGUSR2);
+}
+
 static void load_helper_stop(void)
 {
        assert(lh.igt_proc.running);
@@ -521,7 +550,7 @@ int main(int argc, char **argv)
                min_max_config(idle_check);
 
        igt_subtest("min-max-config-loaded") {
-               load_helper_run();
+               load_helper_run(HIGH);
                min_max_config(loaded_check);
                load_helper_stop();
        }