Add a simple on/off switch that will enable saving power when no
packets are arriving. It is based on counting the number of empty
polls and, when the number reaches a certain threshold, entering an
architecture-defined optimized power state that will either wait
until a TSC timestamp expires, or when packets arrive.
This API is limited to 1 core 1 port 1 queue use case as there is
no coordination between queues/cores in ethdev. 1 port map to multiple
core will be supported in next version.
This design leverage RX Callback mechnaism which allow three
different power management methodology co exist.
1. umwait/umonitor:
The TSC timestamp is automatically calculated using current
link speed and RX descriptor ring size, such that the sleep
time is not longer than it would take for a NIC to fill its
entire RX descriptor ring.
2. Pause instruction
Instead of move the core into deeper C state, this lightweight
method use Pause instruction to releaf the processor from
busy polling.
3. Frequency Scaling
Reuse exist rte power library to scale up/down core frequency
depend on traffic volume.
Signed-off-by: Liang Ma <liang.j...@intel.com>
Signed-off-by: Anatoly Burakov <anatoly.bura...@intel.com>
---
lib/librte_power/meson.build | 3 +-
lib/librte_power/rte_power.h | 38 +++++
lib/librte_power/rte_power_pmd_mgmt.c | 184 +++++++++++++++++++++++++
lib/librte_power/rte_power_version.map | 4 +
4 files changed, 228 insertions(+), 1 deletion(-)
create mode 100644 lib/librte_power/rte_power_pmd_mgmt.c
diff --git a/lib/librte_power/meson.build b/lib/librte_power/meson.build
index 78c031c943..44b01afce2 100644
--- a/lib/librte_power/meson.build
+++ b/lib/librte_power/meson.build
@@ -9,6 +9,7 @@ sources = files('rte_power.c', 'power_acpi_cpufreq.c',
'power_kvm_vm.c', 'guest_channel.c',
'rte_power_empty_poll.c',
'power_pstate_cpufreq.c',
+ 'rte_power_pmd_mgmt.c',
'power_common.c')
headers = files('rte_power.h','rte_power_empty_poll.h')
-deps += ['timer']
+deps += ['timer' ,'ethdev']
diff --git a/lib/librte_power/rte_power.h b/lib/librte_power/rte_power.h
index bbbde4dfb4..06d5a9984f 100644
--- a/lib/librte_power/rte_power.h
+++ b/lib/librte_power/rte_power.h
@@ -14,6 +14,7 @@
#include <rte_byteorder.h>
#include <rte_log.h>
#include <rte_string_fns.h>
+#include <rte_ethdev.h>
#ifdef __cplusplus
extern "C" {
@@ -97,6 +98,43 @@ int rte_power_init(unsigned int lcore_id);
*/
int rte_power_exit(unsigned int lcore_id);
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Enable device power management.
+ * @param lcore_id
+ * lcore id.
+ * @param port_id
+ * The port identifier of the Ethernet device.
+ * @param mode
+ * The power management callback function mode.
+ * @return
+ * 0 on success
+ * <0 on error
+ */
+__rte_experimental
+int rte_power_pmd_mgmt_enable(unsigned int lcore_id,
+ uint16_t port_id,
+ enum rte_eth_dev_power_mgmt_cb_mode mode);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Disable device power management.
+ * @param lcore_id
+ * lcore id.
+ * @param port_id
+ * The port identifier of the Ethernet device.
+ *
+ * @return
+ * 0 on success
+ * <0 on error
+ */
+__rte_experimental
+int rte_power_pmd_mgmt_disable(unsigned int lcore_id, uint16_t port_id);
+
/**
* Get the available frequencies of a specific lcore.
* Function pointer definition. Review each environments
diff --git a/lib/librte_power/rte_power_pmd_mgmt.c
b/lib/librte_power/rte_power_pmd_mgmt.c
new file mode 100644
index 0000000000..a445153ede
--- /dev/null
+++ b/lib/librte_power/rte_power_pmd_mgmt.c
@@ -0,0 +1,184 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2020 Intel Corporation
+ */
+
+#include <rte_lcore.h>
+#include <rte_cycles.h>
+#include <rte_atomic.h>
+#include <rte_malloc.h>
+#include <rte_ethdev.h>
+
+#include "rte_power.h"
+
+
+
+static uint16_t
+rte_power_mgmt_umwait(uint16_t port_id, uint16_t qidx,
+ struct rte_mbuf **pkts __rte_unused, uint16_t nb_rx,
+ uint16_t max_pkts __rte_unused, void *_ __rte_unused)
+{
+
+ struct rte_eth_dev *dev = &rte_eth_devices[port_id];
+
+ if (unlikely(nb_rx == 0)) {
+ dev->empty_poll_stats[qidx].num++;
+ if (unlikely(dev->empty_poll_stats[qidx].num >
+ ETH_EMPTYPOLL_MAX)) {
+ volatile void *target_addr;
+ uint64_t expected, mask;
+ uint16_t ret;
+
+ /*
+ * get address of next descriptor in the RX
+ * ring for this queue, as well as expected
+ * value and a mask.
+ */
+ ret = (*dev->dev_ops->next_rx_desc)
+ (dev->data->rx_queues[qidx],
+ &target_addr, &expected, &mask);
+ if (ret == 0)
+ /* -1ULL is maximum value for TSC */
+ rte_power_monitor(target_addr,
+ expected, mask,
+ 0, -1ULL);
+ }
+ } else
+ dev->empty_poll_stats[qidx].num = 0;
+
+ return nb_rx;
+}
+
+static uint16_t
+rte_power_mgmt_pause(uint16_t port_id, uint16_t qidx,
+ struct rte_mbuf **pkts __rte_unused, uint16_t nb_rx,
+ uint16_t max_pkts __rte_unused, void *_ __rte_unused)
+{
+ struct rte_eth_dev *dev = &rte_eth_devices[port_id];
+
+ int i;
+
+ if (unlikely(nb_rx == 0)) {
+
+ dev->empty_poll_stats[qidx].num++;
+
+ if (unlikely(dev->empty_poll_stats[qidx].num >
+ ETH_EMPTYPOLL_MAX)) {
+
+ for (i = 0; i < RTE_ETH_PAUSE_NUM; i++)
+ rte_pause();
+
+ }
+ } else
+ dev->empty_poll_stats[qidx].num = 0;
+
+ return nb_rx;
+}
+
+static uint16_t
+rte_power_mgmt_scalefreq(uint16_t port_id, uint16_t qidx,
+ struct rte_mbuf **pkts __rte_unused, uint16_t nb_rx,
+ uint16_t max_pkts __rte_unused, void *_ __rte_unused)
+{
+ struct rte_eth_dev *dev = &rte_eth_devices[port_id];
+
+ if (unlikely(nb_rx == 0)) {
+ dev->empty_poll_stats[qidx].num++;
+ if (unlikely(dev->empty_poll_stats[qidx].num >
+ ETH_EMPTYPOLL_MAX)) {
+
+ /*scale down freq */
+ rte_power_freq_min(rte_lcore_id());
+
+ }
+ } else {
+ dev->empty_poll_stats[qidx].num = 0;
+ /* scal up freq */
+ rte_power_freq_max(rte_lcore_id());
+ }
+
+ return nb_rx;
+}
+
+int
+rte_power_pmd_mgmt_enable(unsigned int lcore_id,
+ uint16_t port_id,
+ enum rte_eth_dev_power_mgmt_cb_mode mode)
+{
+ struct rte_eth_dev *dev;
+
+ RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
+ dev = &rte_eth_devices[port_id];
+
+ if (dev->pwr_mgmt_state == RTE_ETH_DEV_POWER_MGMT_ENABLED)
+ return -EINVAL;
+ /* allocate memory for empty poll stats */
+ dev->empty_poll_stats = rte_malloc_socket(NULL,
+ sizeof(struct rte_eth_ep_stat)
+ * RTE_MAX_QUEUES_PER_PORT,
+ 0, dev->data->numa_node);
+ if (dev->empty_poll_stats == NULL)
+ return -ENOMEM;
+
+ switch (mode) {
+ case RTE_ETH_DEV_POWER_MGMT_CB_WAIT:
+ if (!rte_cpu_get_flag_enabled(RTE_CPUFLAG_WAITPKG))
+ return -ENOTSUP;
+ dev->cur_pwr_cb = rte_eth_add_rx_callback(port_id, 0,
+ rte_power_mgmt_umwait, NULL);
+ break;
+ case RTE_ETH_DEV_POWER_MGMT_CB_SCALE:
+ /* init scale freq */
+ if (rte_power_init(lcore_id))
+ return -EINVAL;
+ dev->cur_pwr_cb = rte_eth_add_rx_callback(port_id, 0,
+ rte_power_mgmt_scalefreq, NULL);
+ break;
+ case RTE_ETH_DEV_POWER_MGMT_CB_PAUSE:
+ dev->cur_pwr_cb = rte_eth_add_rx_callback(port_id, 0,
+ rte_power_mgmt_pause, NULL);
+ break;
+ }
+
+ dev->cb_mode = mode;
+ dev->pwr_mgmt_state = RTE_ETH_DEV_POWER_MGMT_ENABLED;
+ return 0;
+}
+
+int
+rte_power_pmd_mgmt_disable(unsigned int lcore_id,
+ uint16_t port_id)
+{
+ struct rte_eth_dev *dev;
+
+ RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
+ dev = &rte_eth_devices[port_id];
+
+ /*add flag check */
+
+ if (dev->pwr_mgmt_state == RTE_ETH_DEV_POWER_MGMT_DISABLED)
+ return -EINVAL;
+
+ /* rte_free ignores NULL so safe to call without checks */
+ rte_free(dev->empty_poll_stats);
+
+ switch (dev->cb_mode) {
+ case RTE_ETH_DEV_POWER_MGMT_CB_WAIT:
+ case RTE_ETH_DEV_POWER_MGMT_CB_PAUSE:
+ rte_eth_remove_rx_callback(port_id, 0,
+ dev->cur_pwr_cb);
+ break;
+ case RTE_ETH_DEV_POWER_MGMT_CB_SCALE:
+ rte_power_freq_max(lcore_id);
+ rte_eth_remove_rx_callback(port_id, 0,
+ dev->cur_pwr_cb);
+ if (rte_power_exit(lcore_id))
+ return -EINVAL;
+ break;
+ }
+
+ dev->pwr_mgmt_state = RTE_ETH_DEV_POWER_MGMT_DISABLED;
+ dev->cur_pwr_cb = NULL;
+ dev->cb_mode = 0;
+
+ return 0;
+}
diff --git a/lib/librte_power/rte_power_version.map
b/lib/librte_power/rte_power_version.map
index 00ee5753e2..ade83cfd4f 100644
--- a/lib/librte_power/rte_power_version.map
+++ b/lib/librte_power/rte_power_version.map
@@ -34,4 +34,8 @@ EXPERIMENTAL {
rte_power_guest_channel_receive_msg;
rte_power_poll_stat_fetch;
rte_power_poll_stat_update;
+ # added in 20.08
+ rte_power_pmd_mgmt_disable;
+ rte_power_pmd_mgmt_enable;
+
};
--
2.17.1
