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* [dpdk-dev] [PATCH v2 1/3] examples/vm_power_manager: Make branch ratio threshold per core
@ 2020-05-18 10:39 Sexton, Rory
  2020-05-18 10:39 ` [dpdk-dev] [PATCH v2 2/3] examples/vm_power_manager: Allowing power managing of idle cores Sexton, Rory
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Sexton, Rory @ 2020-05-18 10:39 UTC (permalink / raw)
  To: dev, david.hunt; +Cc: Sexton, Rory

This modification allows for the branch ratio threshold to be set
per core rather than system wide. This gives greater flexibility to
the branch ration monitoring allowing it to manage different
workloads with different characteristics on the same system.

Signed-off-by: Rory Sexton <rory.sexton@intel.com>
---
 examples/vm_power_manager/main.c            | 40 +++++++++++---------
 examples/vm_power_manager/oob_monitor_x86.c |  2 +-
 examples/vm_power_manager/parse.c           | 42 ++++++++++++++++++++-
 examples/vm_power_manager/parse.h           |  3 ++
 examples/vm_power_manager/power_manager.c   |  2 +-
 examples/vm_power_manager/power_manager.h   |  2 +-
 6 files changed, 68 insertions(+), 23 deletions(-)

diff --git a/examples/vm_power_manager/main.c b/examples/vm_power_manager/main.c
index 273bfec29..f077e3fe4 100644
--- a/examples/vm_power_manager/main.c
+++ b/examples/vm_power_manager/main.c
@@ -165,15 +165,14 @@ parse_args(int argc, char **argv)
 	static struct option lgopts[] = {
 		{ "mac-updating", no_argument, 0, 1},
 		{ "no-mac-updating", no_argument, 0, 0},
-		{ "core-list", optional_argument, 0, 'l'},
+		{ "core-branch-ratio", optional_argument, 0, 'b'},
 		{ "port-list", optional_argument, 0, 'p'},
-		{ "branch-ratio", optional_argument, 0, 'b'},
 		{NULL, 0, 0, 0}
 	};
 	argvopt = argv;
 	ci = get_core_info();
 
-	while ((opt = getopt_long(argc, argvopt, "l:p:q:T:b:",
+	while ((opt = getopt_long(argc, argvopt, "p:q:T:b:",
 				  lgopts, &option_index)) != EOF) {
 
 		switch (opt) {
@@ -185,7 +184,8 @@ parse_args(int argc, char **argv)
 				return -1;
 			}
 			break;
-		case 'l':
+		case 'b':
+			branch_ratio = BRANCH_RATIO_THRESHOLD;
 			oob_enable = malloc(ci->core_count * sizeof(uint16_t));
 			if (oob_enable == NULL) {
 				printf("Error - Unable to allocate memory\n");
@@ -193,32 +193,37 @@ parse_args(int argc, char **argv)
 			}
 			cnt = parse_set(optarg, oob_enable, ci->core_count);
 			if (cnt < 0) {
-				printf("Invalid core-list - [%s]\n",
+				printf("Invalid core-list section in "
+				       "core-branch-ratio matrix - [%s]\n",
+						optarg);
+				free(oob_enable);
+				break;
+			}
+			cnt = parse_branch_ratio(optarg, &branch_ratio);
+			if (cnt < 0) {
+				printf("Invalid branch-ratio section in "
+				       "core-branch-ratio matrix - [%s]\n",
 						optarg);
 				free(oob_enable);
 				break;
 			}
+			if (branch_ratio <= 0.0) {
+				printf("invalid branch ratio specified\n");
+				return -1;
+			}
 			for (i = 0; i < ci->core_count; i++) {
 				if (oob_enable[i]) {
-					printf("***Using core %d\n", i);
+					printf("***Using core %d "
+					       "with branch ratio %f\n",
+					       i, branch_ratio);
 					ci->cd[i].oob_enabled = 1;
 					ci->cd[i].global_enabled_cpus = 1;
+					ci->cd[i].branch_ratio_threshold =
+								branch_ratio;
 				}
 			}
 			free(oob_enable);
 			break;
-		case 'b':
-			branch_ratio = 0.0;
-			if (strlen(optarg))
-				branch_ratio = atof(optarg);
-			if (branch_ratio <= 0.0) {
-				printf("invalid branch ratio specified\n");
-				return -1;
-			}
-			ci->branch_ratio_threshold = branch_ratio;
-			printf("***Setting branch ratio to %f\n",
-					branch_ratio);
-			break;
 		/* long options */
 		case 0:
 			break;
diff --git a/examples/vm_power_manager/oob_monitor_x86.c b/examples/vm_power_manager/oob_monitor_x86.c
index aecfcb2eb..3c514475f 100644
--- a/examples/vm_power_manager/oob_monitor_x86.c
+++ b/examples/vm_power_manager/oob_monitor_x86.c
@@ -109,7 +109,7 @@ apply_policy(int core)
 	 * down. Each core_details struct has it's own array.
 	 */
 	freq_window_idx = ci->cd[core].freq_window_idx;
-	if (ratio > ci->branch_ratio_threshold)
+	if (ratio > ci->cd[core].branch_ratio_threshold)
 		ci->cd[core].freq_directions[freq_window_idx] = 1;
 	else
 		ci->cd[core].freq_directions[freq_window_idx] = 0;
diff --git a/examples/vm_power_manager/parse.c b/examples/vm_power_manager/parse.c
index 8231533b6..8a8dcf05f 100644
--- a/examples/vm_power_manager/parse.c
+++ b/examples/vm_power_manager/parse.c
@@ -60,7 +60,7 @@ parse_set(const char *input, uint16_t set[], unsigned int num)
 				min = idx;
 			else /* avoid continuous '-' */
 				return -1;
-		} else if ((*end == ',') || (*end == '\0')) {
+		} else if ((*end == ',') || (*end == ':') || (*end == '\0')) {
 			max = idx;
 
 			if (min == num)
@@ -75,7 +75,45 @@ parse_set(const char *input, uint16_t set[], unsigned int num)
 			return -1;
 
 		str = end + 1;
-	} while (*end != '\0');
+	} while ((*end != '\0') && (*end != ':'));
+
+	return str - input;
+}
+
+int
+parse_branch_ratio(const char *input, float *branch_ratio)
+{
+	const char *str = input;
+	char *end = NULL;
+
+	while (isblank(*str))
+		str++;
+
+	if (*str == '\0')
+		return -1;
+
+	/* Go straight to the ':' separator if present */
+	while ((*str != '\0') && (*str != ':'))
+		str++;
+
+	/* Branch ratio not specified in args so leave it at default setting */
+	if (*str == '\0')
+		return 0;
+
+	/* Confirm ':' separator present */
+	if (*str != ':')
+		return -1;
+
+	str++;
+	errno = 0;
+	*branch_ratio = strtof(str, &end);
+	if (errno || end == NULL)
+		return -1;
+
+	if (*end != '\0')
+		return -1;
+
+	str = end + 1;
 
 	return str - input;
 }
diff --git a/examples/vm_power_manager/parse.h b/examples/vm_power_manager/parse.h
index a5971e9a2..892dee449 100644
--- a/examples/vm_power_manager/parse.h
+++ b/examples/vm_power_manager/parse.h
@@ -12,6 +12,9 @@ extern "C" {
 int
 parse_set(const char *, uint16_t [], unsigned int);
 
+int
+parse_branch_ratio(const char *input, float *branch_ratio);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/examples/vm_power_manager/power_manager.c b/examples/vm_power_manager/power_manager.c
index 7b4f4b3c4..b52128db1 100644
--- a/examples/vm_power_manager/power_manager.c
+++ b/examples/vm_power_manager/power_manager.c
@@ -60,7 +60,6 @@ core_info_init(void)
 	ci = get_core_info();
 
 	ci->core_count = get_nprocs_conf();
-	ci->branch_ratio_threshold = BRANCH_RATIO_THRESHOLD;
 	ci->cd = malloc(ci->core_count * sizeof(struct core_details));
 	memset(ci->cd, 0, ci->core_count * sizeof(struct core_details));
 	if (!ci->cd) {
@@ -69,6 +68,7 @@ core_info_init(void)
 	}
 	for (i = 0; i < ci->core_count; i++) {
 		ci->cd[i].global_enabled_cpus = 1;
+		ci->cd[i].branch_ratio_threshold = BRANCH_RATIO_THRESHOLD;
 	}
 	printf("%d cores in system\n", ci->core_count);
 	return 0;
diff --git a/examples/vm_power_manager/power_manager.h b/examples/vm_power_manager/power_manager.h
index e324766b6..d35f8cbe0 100644
--- a/examples/vm_power_manager/power_manager.h
+++ b/examples/vm_power_manager/power_manager.h
@@ -26,12 +26,12 @@ struct core_details {
 	uint16_t freq_directions[FREQ_WINDOW_SIZE];
 	uint16_t freq_window_idx;
 	uint16_t freq_state;
+	float branch_ratio_threshold;
 };
 
 struct core_info {
 	uint16_t core_count;
 	struct core_details *cd;
-	float branch_ratio_threshold;
 };
 
 #define BRANCH_RATIO_THRESHOLD 0.1
-- 
2.17.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [dpdk-dev] [PATCH v2 2/3] examples/vm_power_manager: Allowing power managing of idle cores
  2020-05-18 10:39 [dpdk-dev] [PATCH v2 1/3] examples/vm_power_manager: Make branch ratio threshold per core Sexton, Rory
@ 2020-05-18 10:39 ` Sexton, Rory
  2020-06-25 10:17   ` Hunt, David
  2020-05-18 10:39 ` [dpdk-dev] [PATCH v2 3/3] doc: update vm_power_manager cmdline options in doc Sexton, Rory
  2020-06-25 10:14 ` [dpdk-dev] [PATCH v2 1/3] examples/vm_power_manager: Make branch ratio threshold per core Hunt, David
  2 siblings, 1 reply; 6+ messages in thread
From: Sexton, Rory @ 2020-05-18 10:39 UTC (permalink / raw)
  To: dev, david.hunt; +Cc: Sexton, Rory

This change is required to allow the branch ratio algorithm to
power manage cores with no workload running on them. This is
useful both when idle cores don't use C-states and for a number of
hyperthreading scenarios.

Signed-off-by: Rory Sexton <rory.sexton@intel.com>
---
 examples/vm_power_manager/oob_monitor_x86.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/examples/vm_power_manager/oob_monitor_x86.c b/examples/vm_power_manager/oob_monitor_x86.c
index 3c514475f..a5b1c168c 100644
--- a/examples/vm_power_manager/oob_monitor_x86.c
+++ b/examples/vm_power_manager/oob_monitor_x86.c
@@ -96,12 +96,12 @@ apply_policy(int core)
 	g_branch_misses = miss_diff;
 
 	if (hits_diff < (INTERVAL*100)) {
-		/* Likely no workload running on this core. Skip. */
-		return -1.0;
+		/* Likely no workload running on this core. */
+		ratio = 0.0;
+	} else {
+		ratio = (float)miss_diff * (float)100 / (float)hits_diff;
 	}
 
-	ratio = (float)miss_diff * (float)100 / (float)hits_diff;
-
 	/*
 	 * Store the last few directions that the ratio indicates
 	 * we should take. If there's on 'up', then we scale up
-- 
2.17.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [dpdk-dev] [PATCH v2 3/3] doc: update vm_power_manager cmdline options in doc
  2020-05-18 10:39 [dpdk-dev] [PATCH v2 1/3] examples/vm_power_manager: Make branch ratio threshold per core Sexton, Rory
  2020-05-18 10:39 ` [dpdk-dev] [PATCH v2 2/3] examples/vm_power_manager: Allowing power managing of idle cores Sexton, Rory
@ 2020-05-18 10:39 ` Sexton, Rory
  2020-06-25 10:21   ` Hunt, David
  2020-06-25 10:14 ` [dpdk-dev] [PATCH v2 1/3] examples/vm_power_manager: Make branch ratio threshold per core Hunt, David
  2 siblings, 1 reply; 6+ messages in thread
From: Sexton, Rory @ 2020-05-18 10:39 UTC (permalink / raw)
  To: dev, david.hunt; +Cc: Sexton, Rory

Signed-off-by: Rory Sexton <rory.sexton@intel.com>
---
 doc/guides/sample_app_ug/vm_power_management.rst | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/doc/guides/sample_app_ug/vm_power_management.rst b/doc/guides/sample_app_ug/vm_power_management.rst
index e98277ccb..dd0f46158 100644
--- a/doc/guides/sample_app_ug/vm_power_management.rst
+++ b/doc/guides/sample_app_ug/vm_power_management.rst
@@ -410,20 +410,17 @@ There are a couple of command line parameters for enabling the out-of-band
 monitoring of branch ratios on cores doing busy polling using PMDs as
 described below:
 
-``--core-list {list of cores}``
+``--core-branch-ratio {list of cores}:{branch ratio for listed cores}``
    Specify the list of cores to monitor the ratio of branch misses
    to branch hits.  A tightly-polling PMD thread has a very low
    branch ratio, therefore the core frequency scales down to the
    minimum allowed value. On receiving packets, the code path changes,
    causing the branch ratio to increase. When the ratio goes above
    the ratio threshold, the core frequency scales up to the maximum
-   allowed value.
-
-``--branch-ratio {ratio}``
-   Specify a floating-point number that identifies the threshold at which
-   to scale up or down for the given workload. The default branch ratio
-   is 0.01 and needs adjustment for different workloads.
-
+   allowed value. The specified branch-ratio is a floating point number
+   that identifies the threshold at which to scale up or down for the
+   elements of the core-list. If not included the default branch ratio of
+   0.01 but will need adjustment for different workloads
 
 Compiling and Running the Guest Applications
 --------------------------------------------
-- 
2.17.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH v2 1/3] examples/vm_power_manager: Make branch ratio threshold per core
  2020-05-18 10:39 [dpdk-dev] [PATCH v2 1/3] examples/vm_power_manager: Make branch ratio threshold per core Sexton, Rory
  2020-05-18 10:39 ` [dpdk-dev] [PATCH v2 2/3] examples/vm_power_manager: Allowing power managing of idle cores Sexton, Rory
  2020-05-18 10:39 ` [dpdk-dev] [PATCH v2 3/3] doc: update vm_power_manager cmdline options in doc Sexton, Rory
@ 2020-06-25 10:14 ` Hunt, David
  2 siblings, 0 replies; 6+ messages in thread
From: Hunt, David @ 2020-06-25 10:14 UTC (permalink / raw)
  To: Sexton, Rory, dev

Hi Rory,

On 18/5/2020 11:39 AM, Sexton, Rory wrote:
> This modification allows for the branch ratio threshold to be set
> per core rather than system wide. This gives greater flexibility to
> the branch ration monitoring allowing it to manage different
> workloads with different characteristics on the same system.
>
> Signed-off-by: Rory Sexton <rory.sexton@intel.com>
> ---
>   examples/vm_power_manager/main.c            | 40 +++++++++++---------
>   examples/vm_power_manager/oob_monitor_x86.c |  2 +-
>   examples/vm_power_manager/parse.c           | 42 ++++++++++++++++++++-
>   examples/vm_power_manager/parse.h           |  3 ++
>   examples/vm_power_manager/power_manager.c   |  2 +-
>   examples/vm_power_manager/power_manager.h   |  2 +-
>   6 files changed, 68 insertions(+), 23 deletions(-)


This change is a good enhancement, as there are usually different types 
of workload running on the cores in a system, each requiring a different 
ratio.

Also, it's good that multiple groups of cores can be specified by using 
the parameter multiple times, e.g. -b 21-23:0.5 -b 24,25:0.4

LGTM.

Reviewed-by: David Hunt <david.hunt@intel.com>



^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH v2 2/3] examples/vm_power_manager: Allowing power managing of idle cores
  2020-05-18 10:39 ` [dpdk-dev] [PATCH v2 2/3] examples/vm_power_manager: Allowing power managing of idle cores Sexton, Rory
@ 2020-06-25 10:17   ` Hunt, David
  0 siblings, 0 replies; 6+ messages in thread
From: Hunt, David @ 2020-06-25 10:17 UTC (permalink / raw)
  To: Sexton, Rory, dev

Hi Rory,

On 18/5/2020 11:39 AM, Sexton, Rory wrote:
> This change is required to allow the branch ratio algorithm to
> power manage cores with no workload running on them. This is
> useful both when idle cores don't use C-states and for a number of
> hyperthreading scenarios.
>
> Signed-off-by: Rory Sexton <rory.sexton@intel.com>
> ---
>   examples/vm_power_manager/oob_monitor_x86.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/examples/vm_power_manager/oob_monitor_x86.c b/examples/vm_power_manager/oob_monitor_x86.c
> index 3c514475f..a5b1c168c 100644
> --- a/examples/vm_power_manager/oob_monitor_x86.c
> +++ b/examples/vm_power_manager/oob_monitor_x86.c
> @@ -96,12 +96,12 @@ apply_policy(int core)
>   	g_branch_misses = miss_diff;
>   
>   	if (hits_diff < (INTERVAL*100)) {
> -		/* Likely no workload running on this core. Skip. */
> -		return -1.0;
> +		/* Likely no workload running on this core. */
> +		ratio = 0.0;
> +	} else {
> +		ratio = (float)miss_diff * (float)100 / (float)hits_diff;
>   	}
>   
> -	ratio = (float)miss_diff * (float)100 / (float)hits_diff;
> -
>   	/*
>   	 * Store the last few directions that the ratio indicates
>   	 * we should take. If there's on 'up', then we scale up


Good enhancement. It hadn't occurred to me to manage non-PMD workloads, 
but I agree that when
C-States are disabled on a system, there may be cases where this 
algorithm is useful to save power.

Reviewed-by: David Hunt <david.hunt@intel.com>




^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH v2 3/3] doc: update vm_power_manager cmdline options in doc
  2020-05-18 10:39 ` [dpdk-dev] [PATCH v2 3/3] doc: update vm_power_manager cmdline options in doc Sexton, Rory
@ 2020-06-25 10:21   ` Hunt, David
  0 siblings, 0 replies; 6+ messages in thread
From: Hunt, David @ 2020-06-25 10:21 UTC (permalink / raw)
  To: Sexton, Rory, dev


On 18/5/2020 11:39 AM, Sexton, Rory wrote:
> Signed-off-by: Rory Sexton <rory.sexton@intel.com>
> ---
>   doc/guides/sample_app_ug/vm_power_management.rst | 13 +++++--------
>   1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/doc/guides/sample_app_ug/vm_power_management.rst b/doc/guides/sample_app_ug/vm_power_management.rst
> index e98277ccb..dd0f46158 100644
> --- a/doc/guides/sample_app_ug/vm_power_management.rst
> +++ b/doc/guides/sample_app_ug/vm_power_management.rst
> @@ -410,20 +410,17 @@ There are a couple of command line parameters for enabling the out-of-band
>   monitoring of branch ratios on cores doing busy polling using PMDs as
>   described below:
>   
> -``--core-list {list of cores}``
> +``--core-branch-ratio {list of cores}:{branch ratio for listed cores}``
>      Specify the list of cores to monitor the ratio of branch misses
>      to branch hits.  A tightly-polling PMD thread has a very low
>      branch ratio, therefore the core frequency scales down to the
>      minimum allowed value. On receiving packets, the code path changes,
>      causing the branch ratio to increase. When the ratio goes above
>      the ratio threshold, the core frequency scales up to the maximum
> -   allowed value.
> -
> -``--branch-ratio {ratio}``
> -   Specify a floating-point number that identifies the threshold at which
> -   to scale up or down for the given workload. The default branch ratio
> -   is 0.01 and needs adjustment for different workloads.
> -
> +   allowed value. The specified branch-ratio is a floating point number
> +   that identifies the threshold at which to scale up or down for the
> +   elements of the core-list. If not included the default branch ratio of
> +   0.01 but will need adjustment for different workloads

Could I suggest adding something along the following lines for further info?

"This parameter can be used multiple times for different sets of cores.
The branch ratio mechanism can also be useful for non-PMD cores and 
hyper-threaded
environments where C-States are disabled."


Reviewed-by: David Hunt <david.hunt@intel.com>






^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2020-06-25 10:21 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2020-05-18 10:39 [dpdk-dev] [PATCH v2 1/3] examples/vm_power_manager: Make branch ratio threshold per core Sexton, Rory
2020-05-18 10:39 ` [dpdk-dev] [PATCH v2 2/3] examples/vm_power_manager: Allowing power managing of idle cores Sexton, Rory
2020-06-25 10:17   ` Hunt, David
2020-05-18 10:39 ` [dpdk-dev] [PATCH v2 3/3] doc: update vm_power_manager cmdline options in doc Sexton, Rory
2020-06-25 10:21   ` Hunt, David
2020-06-25 10:14 ` [dpdk-dev] [PATCH v2 1/3] examples/vm_power_manager: Make branch ratio threshold per core Hunt, David

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