[dpdk-dev] [PATCH v3 7/7] l3fwd-power: add auto-selection of default mode

[Anatoly Burakov]

Currently, the application does support running without the power
library being initialized, but it has to be specifically requested. On
platforms without support for frequency scaling using the power library,
we can just enable interrupt-only mode by default.

Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
Suggested-by: Jerin Jacob <jerinjacobk at gmail.com>
Tested-by: Harman Kalra <hkalra at marvell.com>
---
 examples/l3fwd-power/main.c | 41 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/examples/l3fwd-power/main.c b/examples/l3fwd-power/main.c
index 51acbfd87d..6a4a27984b 100644
--- a/examples/l3fwd-power/main.c
+++ b/examples/l3fwd-power/main.c
@@ -2412,6 +2412,42 @@ launch_timer(unsigned int lcore_id)
 	return 0;
 }
 
+static int
+autodetect_mode(void)
+{
+	RTE_LOG(NOTICE, L3FWD_POWER, "Operating mode not specified, probing frequency scaling support...\n");
+
+	/*
+	 * Empty poll and telemetry modes have to be specifically requested to
+	 * be enabled, but we can auto-detect between interrupt mode with or
+	 * without frequency scaling. Both ACPI and pstate can be used.
+	 */
+	if (rte_power_check_env_supported(PM_ENV_ACPI_CPUFREQ))
+		return APP_MODE_LEGACY;
+	if (rte_power_check_env_supported(PM_ENV_PSTATE_CPUFREQ))
+		return APP_MODE_LEGACY;
+
+	RTE_LOG(NOTICE, L3FWD_POWER, "Frequency scaling not supported, selecting interrupt-only mode\n");
+
+	return APP_MODE_INTERRUPT;
+}
+
+static const char *
+mode_to_str(enum appmode mode)
+{
+	switch (mode) {
+	case APP_MODE_LEGACY:
+		return "legacy";
+	case APP_MODE_EMPTY_POLL:
+		return "empty poll";
+	case APP_MODE_TELEMETRY:
+		return "telemetry";
+	case APP_MODE_INTERRUPT:
+		return "interrupt-only";
+	default:
+		return "invalid";
+	}
+}
 
 int
 main(int argc, char **argv)
@@ -2449,7 +2485,10 @@ main(int argc, char **argv)
 		rte_exit(EXIT_FAILURE, "Invalid L3FWD parameters\n");
 
 	if (app_mode == APP_MODE_DEFAULT)
-		app_mode = APP_MODE_LEGACY;
+		app_mode = autodetect_mode();
+
+	RTE_LOG(INFO, L3FWD_POWER, "Selected operation mode: %s\n",
+			mode_to_str(app_mode));
 
 	/* only legacy and empty poll mode rely on power library */
 	if ((app_mode == APP_MODE_LEGACY || app_mode == APP_MODE_EMPTY_POLL) &&
-- 
2.17.1