Re: [dpdk-dev] [PATCH v2 07/10] librte_power common interface for Guest and Host

["Carew, Alan" <alan.carew@intel.com>]

> -----Original Message-----
> From: Neil Horman [mailto:nhorman@tuxdriver.com]
> Sent: Thursday, September 25, 2014 11:10 AM
> To: Carew, Alan
> Cc: dev@dpdk.org
> Subject: Re: [PATCH v2 07/10] librte_power common interface for Guest and
> Host
> 
> On Wed, Sep 24, 2014 at 06:26:13PM +0100, Alan Carew wrote:
> > Moved the current librte_power implementation to rte_power_acpi_cpufreq,
> with
> > renaming of functions only.
> > Added rte_power_kvm_vm implmentation to support Power Management
> from a VM.
> >
> > librte_power now hides the implementation based on the environment used.
> > A new call rte_power_set_env() can explicidly set the environment, if not
> > called then auto-detection takes place.
> >
> > rte_power_kvm_vm is subset of the librte_power APIs, the following is
> supported:
> >  rte_power_init(unsigned lcore_id)
> >  rte_power_exit(unsigned lcore_id)
> >  rte_power_freq_up(unsigned lcore_id)
> >  rte_power_freq_down(unsigned lcore_id)
> >  rte_power_freq_min(unsigned lcore_id)
> >  rte_power_freq_max(unsigned lcore_id)
> >
> > The other unsupported APIs return -ENOTSUP
> >
> > Signed-off-by: Alan Carew <alan.carew@intel.com>
> > ---
> >  lib/librte_power/rte_power.c              | 540 ++++-------------------------
> >  lib/librte_power/rte_power.h              | 120 +++++--
> >  lib/librte_power/rte_power_acpi_cpufreq.c | 545
> ++++++++++++++++++++++++++++++
> >  lib/librte_power/rte_power_acpi_cpufreq.h | 192 +++++++++++
> >  lib/librte_power/rte_power_common.h       |  39 +++
> >  lib/librte_power/rte_power_kvm_vm.c       | 160 +++++++++
> >  lib/librte_power/rte_power_kvm_vm.h       | 179 ++++++++++
> >  7 files changed, 1273 insertions(+), 502 deletions(-)
> >  create mode 100644 lib/librte_power/rte_power_acpi_cpufreq.c
> >  create mode 100644 lib/librte_power/rte_power_acpi_cpufreq.h
> >  create mode 100644 lib/librte_power/rte_power_common.h
> >  create mode 100644 lib/librte_power/rte_power_kvm_vm.c
> >  create mode 100644 lib/librte_power/rte_power_kvm_vm.h
> >
> > diff --git a/lib/librte_power/rte_power.c b/lib/librte_power/rte_power.c
> > index 856da9a..998ed1c 100644
> > --- a/lib/librte_power/rte_power.c
> > +++ b/lib/librte_power/rte_power.c
> > @@ -31,515 +31,113 @@
> >   *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
> DAMAGE.
> >   */
> >
> > -#include <stdio.h>
> > -#include <sys/types.h>
> > -#include <sys/stat.h>
> > -#include <fcntl.h>
> > -#include <stdlib.h>
> > -#include <string.h>
> > -#include <unistd.h>
> > -#include <signal.h>
> > -#include <limits.h>
> > -
> > -#include <rte_memcpy.h>
> >  #include <rte_atomic.h>
> >
> >  #include "rte_power.h"
> > +#include "rte_power_acpi_cpufreq.h"
> > +#include "rte_power_kvm_vm.h"
> > +#include "rte_power_common.h"
> >
> > -#ifdef RTE_LIBRTE_POWER_DEBUG
> > -#define POWER_DEBUG_TRACE(fmt, args...) do { \
> > -		RTE_LOG(ERR, POWER, "%s: " fmt, __func__, ## args); \
> > -	} while (0)
> > -#else
> > -#define POWER_DEBUG_TRACE(fmt, args...)
> > -#endif
> > -
> > -#define FOPEN_OR_ERR_RET(f, retval) do { \
> > -	if ((f) == NULL) { \
> > -		RTE_LOG(ERR, POWER, "File not openned\n"); \
> > -		return (retval); \
> > -	} \
> > -} while(0)
> > -
> > -#define FOPS_OR_NULL_GOTO(ret, label) do { \
> > -	if ((ret) == NULL) { \
> > -		RTE_LOG(ERR, POWER, "fgets returns nothing\n"); \
> > -		goto label; \
> > -	} \
> > -} while(0)
> > -
> > -#define FOPS_OR_ERR_GOTO(ret, label) do { \
> > -	if ((ret) < 0) { \
> > -		RTE_LOG(ERR, POWER, "File operations failed\n"); \
> > -		goto label; \
> > -	} \
> > -} while(0)
> > -
> > -#define STR_SIZE     1024
> > -#define POWER_CONVERT_TO_DECIMAL 10
> > +enum power_management_env global_default_env = PM_ENV_NOT_SET;
> >
> > -#define POWER_GOVERNOR_USERSPACE "userspace"
> > -#define POWER_SYSFILE_GOVERNOR   \
> > -	"/sys/devices/system/cpu/cpu%u/cpufreq/scaling_governor"
> > -#define POWER_SYSFILE_AVAIL_FREQ \
> > -
> 	"/sys/devices/system/cpu/cpu%u/cpufreq/scaling_available_frequencie
> s"
> > -#define POWER_SYSFILE_SETSPEED   \
> > -	"/sys/devices/system/cpu/cpu%u/cpufreq/scaling_setspeed"
> > +volatile uint32_t global_env_cfg_status = 0;
> >
> > -enum power_state {
> > -	POWER_IDLE = 0,
> > -	POWER_ONGOING,
> > -	POWER_USED,
> > -	POWER_UNKNOWN
> > -};
> > +/* function pointers */
> > +rte_power_freqs_t rte_power_freqs  = NULL;
> > +rte_power_get_freq_t rte_power_get_freq = NULL;
> > +rte_power_set_freq_t rte_power_set_freq = NULL;
> > +rte_power_freq_change_t rte_power_freq_up = NULL;
> > +rte_power_freq_change_t rte_power_freq_down = NULL;
> > +rte_power_freq_change_t rte_power_freq_max = NULL;
> > +rte_power_freq_change_t rte_power_freq_min = NULL;
> >
> > -/**
> > - * Power info per lcore.
> > - */
> > -struct rte_power_info {
> > -	unsigned lcore_id;                   /**< Logical core id */
> > -	uint32_t freqs[RTE_MAX_LCORE_FREQS]; /**< Frequency array */
> > -	uint32_t nb_freqs;                   /**< number of available freqs */
> > -	FILE *f;                             /**< FD of scaling_setspeed */
> > -	char governor_ori[32];               /**< Original governor name */
> > -	uint32_t curr_idx;                   /**< Freq index in freqs array */
> > -	volatile uint32_t state;             /**< Power in use state */
> > -} __rte_cache_aligned;
> > -
> > -static struct rte_power_info lcore_power_info[RTE_MAX_LCORE];
> > -
> > -/**
> > - * It is to set specific freq for specific logical core, according to the index
> > - * of supported frequencies.
> > - */
> > -static int
> > -set_freq_internal(struct rte_power_info *pi, uint32_t idx)
> > +int
> > +rte_power_set_env(enum power_management_env env)
> >  {
> > -	if (idx >= RTE_MAX_LCORE_FREQS || idx >= pi->nb_freqs) {
> > -		RTE_LOG(ERR, POWER, "Invalid frequency index %u, which "
> > -			"should be less than %u\n", idx, pi->nb_freqs);
> > -		return -1;
> > -	}
> > -
> > -	/* Check if it is the same as current */
> > -	if (idx == pi->curr_idx)
> > +	if (rte_atomic32_cmpset(&global_env_cfg_status, 0, 1) == 0) {
> >  		return 0;
> > -
> 1 Nit here.  If an invalid environment value is passed in on the first config
> attempt here, you won't ever be able to set it.  Maybe add some logic to return
> us to an initial state if a value env isn't selected?
> 
> Neil

Hi Neil,

I should have called it out in the commit, but there's also a rte_power_unset_env()
function that resets the environment that allows for retrying a different environment.
rte_power_unset_env() is also called when an invalid configuration is set.

Thanks,
Alan.