From: Liang Ma <liang.j...@intel.com>
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 mandates a core-to-single-queue mapping (that is, multiple
queued per device are supported, but they have to be polled on different
cores).
This design is using PMD RX callbacks.
1. UMWAIT/UMONITOR:
When a certain threshold of empty polls is reached, the core will go
into a power optimized sleep while waiting on an address of next RX
descriptor to be written to.
2. Pause instruction
Instead of move the core into deeper C state, this method uses the
pause instruction to avoid busy polling.
3. Frequency scaling
Reuse existing DPDK power library to scale up/down core frequency
depending on traffic volume.
Signed-off-by: Liang Ma <liang.j...@intel.com>
Signed-off-by: Anatoly Burakov <anatoly.bura...@intel.com>
---
Notes:
v5:
- Make error checking more robust
- Prevent initializing scaling if ACPI or PSTATE env wasn't set
- Prevent initializing UMWAIT path if PMD doesn't support get_wake_addr
- Add some debug logging
- Replace x86-specific code path to generic path using the intrinsic check
lib/librte_power/meson.build | 5 +-
lib/librte_power/pmd_mgmt.h | 38 ++++
lib/librte_power/rte_power_pmd_mgmt.c | 244 +++++++++++++++++++++++++
lib/librte_power/rte_power_pmd_mgmt.h | 88 +++++++++
lib/librte_power/rte_power_version.map | 4 +
5 files changed, 377 insertions(+), 2 deletions(-)
create mode 100644 lib/librte_power/pmd_mgmt.h
create mode 100644 lib/librte_power/rte_power_pmd_mgmt.c
create mode 100644 lib/librte_power/rte_power_pmd_mgmt.h
diff --git a/lib/librte_power/meson.build b/lib/librte_power/meson.build
index 78c031c943..cc3c7a8646 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']
+headers = files('rte_power.h','rte_power_empty_poll.h','rte_power_pmd_mgmt.h')
+deps += ['timer' ,'ethdev']
diff --git a/lib/librte_power/pmd_mgmt.h b/lib/librte_power/pmd_mgmt.h
new file mode 100644
index 0000000000..20be53bacf
--- /dev/null
+++ b/lib/librte_power/pmd_mgmt.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2020 Intel Corporation
+ */
+
+#ifndef _PMD_MGMT_H
+#define _PMD_MGMT_H
+
+/**
+ * @file
+ * Power Management
+ */
+
+/**
+ * Possible power management states of an ethdev port.
+ */
+enum pmd_mgmt_state {
+ /** Device power management is disabled. */
+ PMD_MGMT_DISABLED = 0,
+ /** Device power management is enabled. */
+ PMD_MGMT_ENABLED,
+};
+
+struct pmd_queue_cfg {
+ enum pmd_mgmt_state pwr_mgmt_state;
+ /**< Power mgmt Callback mode */
+ enum rte_power_pmd_mgmt_type cb_mode;
+ /**< Empty poll number */
+ uint16_t empty_poll_stats;
+ /**< Callback instance */
+ const struct rte_eth_rxtx_callback *cur_cb;
+} __rte_cache_aligned;
+
+struct pmd_port_cfg {
+ int ref_cnt;
+ struct pmd_queue_cfg *queue_cfg;
+} __rte_cache_aligned;
+
+#endif
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..07dfe7c077
--- /dev/null
+++ b/lib/librte_power/rte_power_pmd_mgmt.c
@@ -0,0 +1,244 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2020 Intel Corporation
+ */
+
+#include <rte_lcore.h>
+#include <rte_cycles.h>
+#include <rte_cpuflags.h>
+#include <rte_malloc.h>
+#include <rte_ethdev.h>
+#include <rte_power_intrinsics.h>
+
+#include "rte_power_pmd_mgmt.h"
+#include "pmd_mgmt.h"
+
+
+#define EMPTYPOLL_MAX 512
+#define PAUSE_NUM 64
+
+static struct pmd_port_cfg port_cfg[RTE_MAX_ETHPORTS];
+
+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 pmd_queue_cfg *q_conf;
+ q_conf = &port_cfg[port_id].queue_cfg[qidx];
+
+ if (unlikely(nb_rx == 0)) {
+ q_conf->empty_poll_stats++;
+ if (unlikely(q_conf->empty_poll_stats > 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 = rte_eth_get_wake_addr(port_id, qidx,
+ &target_addr, &expected, &mask);
+ if (ret == 0)
+ /* -1ULL is maximum value for TSC */
+ rte_power_monitor(target_addr, expected,
+ mask, -1ULL);
+ }
+ } else
+ q_conf->empty_poll_stats = 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 pmd_queue_cfg *q_conf;
+ int i;
+ q_conf = &port_cfg[port_id].queue_cfg[qidx];
+
+ if (unlikely(nb_rx == 0)) {
+ q_conf->empty_poll_stats++;
+ if (unlikely(q_conf->empty_poll_stats > EMPTYPOLL_MAX)) {
+ for (i = 0; i < PAUSE_NUM; i++)
+ rte_pause();
+ }
+ } else
+ q_conf->empty_poll_stats = 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 pmd_queue_cfg *q_conf;
+ q_conf = &port_cfg[port_id].queue_cfg[qidx];
+
+ if (unlikely(nb_rx == 0)) {
+ q_conf->empty_poll_stats++;
+ if (unlikely(q_conf->empty_poll_stats > EMPTYPOLL_MAX)) {
+ /*scale down freq */
+ rte_power_freq_min(rte_lcore_id());
+
+ }
+ } else {
+ q_conf->empty_poll_stats = 0;
+ /* scal up freq */
+ rte_power_freq_max(rte_lcore_id());
+ }
+
+ return nb_rx;
+}
+
+int
+rte_power_pmd_mgmt_queue_enable(unsigned int lcore_id,
+ uint16_t port_id,
+ uint16_t queue_id,
+ enum rte_power_pmd_mgmt_type mode)
+{
+ struct rte_eth_dev *dev;
+ struct pmd_queue_cfg *queue_cfg;
+ int ret = 0;
+
+ RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
+ dev = &rte_eth_devices[port_id];
+
+ if (port_cfg[port_id].queue_cfg == NULL) {
+ port_cfg[port_id].ref_cnt = 0;
+ /* allocate memory for empty poll stats */
+ port_cfg[port_id].queue_cfg = rte_malloc_socket(NULL,
+ sizeof(struct pmd_queue_cfg)
+ * RTE_MAX_QUEUES_PER_PORT,
+ 0, dev->data->numa_node);
+ if (port_cfg[port_id].queue_cfg == NULL)
+ return -ENOMEM;
+ }
+
+ queue_cfg = &port_cfg[port_id].queue_cfg[queue_id];
+
+ if (queue_cfg->pwr_mgmt_state == PMD_MGMT_ENABLED) {
+ ret = -EINVAL;
+ goto failure_handler;
+ }
+
+ switch (mode) {
+ case RTE_POWER_MGMT_TYPE_WAIT:
+ {
+ /* check if rte_power_monitor is supported */
+ uint64_t dummy_expected, dummy_mask;
+ struct rte_cpu_intrinsics i;
+ void *dummy_addr;
+
+ rte_cpu_get_intrinsics_support(&i);
+
+ if (!i.power_monitor) {
+ RTE_LOG(DEBUG, POWER, "Monitoring intrinsics are not
supported\n");
+ ret = -ENOTSUP;
+ goto failure_handler;
+ }
+
+ /* check if the device supports the necessary PMD API */
+ if (rte_eth_get_wake_addr(port_id, queue_id, &dummy_addr,
+ &dummy_expected, &dummy_mask) == -ENOTSUP) {
+ RTE_LOG(DEBUG, POWER, "The device does not support
get_wake_addr\n");
+ ret = -ENOTSUP;
+ goto failure_handler;
+ }
+
+ queue_cfg->cur_cb = rte_eth_add_rx_callback(port_id, queue_id,
+ rte_power_mgmt_umwait, NULL);
+ break;
+ }
+ case RTE_POWER_MGMT_TYPE_SCALE:
+ {
+ enum power_management_env env;
+ /* only PSTATE and ACPI modes are supported */
+ if (!rte_power_check_env_supported(PM_ENV_ACPI_CPUFREQ) &&
+ !rte_power_check_env_supported(PM_ENV_PSTATE_CPUFREQ)) {
+ RTE_LOG(DEBUG, POWER, "Neither ACPI nor PSTATE modes
are supported\n");
+ ret = -ENOTSUP;
+ goto failure_handler;
+ }
+ /* ensure we could initialize the power library */
+ if (rte_power_init(lcore_id)) {
+ ret = -EINVAL;
+ goto failure_handler;
+ }
+ /* ensure we initialized the correct env */
+ env = rte_power_get_env();
+ if (env != PM_ENV_ACPI_CPUFREQ &&
+ env != PM_ENV_PSTATE_CPUFREQ) {
+ RTE_LOG(DEBUG, POWER, "Neither ACPI nor PSTATE modes
were initialized\n");
+ ret = -ENOTSUP;
+ goto failure_handler;
+ }
+ queue_cfg->cur_cb = rte_eth_add_rx_callback(port_id, queue_id,
+ rte_power_mgmt_scalefreq, NULL);
+ break;
+ }
+ case RTE_POWER_MGMT_TYPE_PAUSE:
+ queue_cfg->cur_cb = rte_eth_add_rx_callback(port_id, queue_id,
+ rte_power_mgmt_pause, NULL);
+ break;
+ }
+ queue_cfg->cb_mode = mode;
+ port_cfg[port_id].ref_cnt++;
+ queue_cfg->pwr_mgmt_state = PMD_MGMT_ENABLED;
+ return ret;
+
+failure_handler:
+ if (port_cfg[port_id].ref_cnt == 0) {
+ rte_free(port_cfg[port_id].queue_cfg);
+ port_cfg[port_id].queue_cfg = NULL;
+ }
+ return ret;
+}
+
+int
+rte_power_pmd_mgmt_queue_disable(unsigned int lcore_id,
+ uint16_t port_id,
+ uint16_t queue_id)
+{
+ struct pmd_queue_cfg *queue_cfg;
+
+ if (port_cfg[port_id].ref_cnt <= 0)
+ return -EINVAL;
+
+ queue_cfg = &port_cfg[port_id].queue_cfg[queue_id];
+
+ if (queue_cfg->pwr_mgmt_state == PMD_MGMT_DISABLED)
+ return -EINVAL;
+
+ switch (queue_cfg->cb_mode) {
+ case RTE_POWER_MGMT_TYPE_WAIT:
+ case RTE_POWER_MGMT_TYPE_PAUSE:
+ rte_eth_remove_rx_callback(port_id, queue_id,
+ queue_cfg->cur_cb);
+ break;
+ case RTE_POWER_MGMT_TYPE_SCALE:
+ rte_power_freq_max(lcore_id);
+ rte_eth_remove_rx_callback(port_id, queue_id,
+ queue_cfg->cur_cb);
+ rte_power_exit(lcore_id);
+ break;
+ }
+ /* it's not recommend to free callback instance here.
+ * it cause memory leak which is a known issue.
+ */
+ queue_cfg->cur_cb = NULL;
+ queue_cfg->pwr_mgmt_state = PMD_MGMT_DISABLED;
+ port_cfg[port_id].ref_cnt--;
+
+ if (port_cfg[port_id].ref_cnt == 0) {
+ rte_free(port_cfg[port_id].queue_cfg);
+ port_cfg[port_id].queue_cfg = NULL;
+ }
+ return 0;
+}
diff --git a/lib/librte_power/rte_power_pmd_mgmt.h
b/lib/librte_power/rte_power_pmd_mgmt.h
new file mode 100644
index 0000000000..8b110f1148
--- /dev/null
+++ b/lib/librte_power/rte_power_pmd_mgmt.h
@@ -0,0 +1,88 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2020 Intel Corporation
+ */
+
+#ifndef _RTE_POWER_PMD_MGMT_H
+#define _RTE_POWER_PMD_MGMT_H
+
+/**
+ * @file
+ * RTE PMD Power Management
+ */
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <rte_common.h>
+#include <rte_byteorder.h>
+#include <rte_log.h>
+#include <rte_power.h>
+#include <rte_atomic.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * PMD Power Management Type
+ */
+enum rte_power_pmd_mgmt_type {
+ /** WAIT callback mode. */
+ RTE_POWER_MGMT_TYPE_WAIT = 1,
+ /** PAUSE callback mode. */
+ RTE_POWER_MGMT_TYPE_PAUSE,
+ /** Freq Scaling callback mode. */
+ RTE_POWER_MGMT_TYPE_SCALE,
+};
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Setup per-queue power management callback.
+ * @param lcore_id
+ * lcore_id.
+ * @param port_id
+ * The port identifier of the Ethernet device.
+ * @param queue_id
+ * The queue identifier of the Ethernet device.
+ * @param mode
+ * The power management callback function type.
+
+ * @return
+ * 0 on success
+ * <0 on error
+ */
+
+__rte_experimental
+int
+rte_power_pmd_mgmt_queue_enable(unsigned int lcore_id,
+ uint16_t port_id,
+ uint16_t queue_id,
+ enum rte_power_pmd_mgmt_type mode);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Remove per-queue power management callback.
+ * @param lcore_id
+ * lcore_id.
+ * @param port_id
+ * The port identifier of the Ethernet device.
+ * @param queue_id
+ * The queue identifier of the Ethernet device.
+ * @return
+ * 0 on success
+ * <0 on error
+ */
+
+__rte_experimental
+int
+rte_power_pmd_mgmt_queue_disable(unsigned int lcore_id,
+ uint16_t port_id,
+ uint16_t queue_id);
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/lib/librte_power/rte_power_version.map
b/lib/librte_power/rte_power_version.map
index 69ca9af616..3f2f6cd6f6 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 20.11
+ rte_power_pmd_mgmt_queue_enable;
+ rte_power_pmd_mgmt_queue_disable;
+
};
--
2.17.1
