Skip to contentSkip to conversation

intel_idle: shrink states tables

PATCH In review Bartlomiej Zolnierkiewicz 3 participants 3 messages Aug 30, 2013 – Sep 2, 2013 Intel idle driver

lore
Share & tools
lore
#0 lore raw

PATCH 1/3 intel_idle: shrink states tables

There is no reason to define CPUIDLE_STATE_MAX (currently 10) entries in states tables if the driver always stops iterating over table when it encounters first .enter == NULL entry.

$ size drivers/idle/intel_idle.o.*
   text    data     bss     dec     hex filename
   2886    5440      32    8358    20a6 drivers/idle/intel_idle.o.before
   2886    3752      32    6670    1a0e drivers/idle/intel_idle.o.after
---
 drivers/idle/intel_idle.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
drivers/idle/intel_idle.c +6 -6
index fa6964d..9c97fbb42 100644
@@ -123,7 +123,7 @@ static struct cpuidle_state *cpuidle_state_table;
  * which is also the index into the MWAIT hint array.
  * Thus C0 is a dummy.
  */
-static struct cpuidle_state nehalem_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state nehalem_cstates[] = {
 	{
 		.name = "C1-NHM",
 		.desc = "MWAIT 0x00",
@@ -156,7 +156,7 @@ static struct cpuidle_state nehalem_cstates[CPUIDLE_STATE_MAX] = {
 		.enter = NULL }
 };
 
-static struct cpuidle_state snb_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state snb_cstates[] = {
 	{
 		.name = "C1-SNB",
 		.desc = "MWAIT 0x00",
@@ -196,7 +196,7 @@ static struct cpuidle_state snb_cstates[CPUIDLE_STATE_MAX] = {
 		.enter = NULL }
 };
 
-static struct cpuidle_state ivb_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state ivb_cstates[] = {
 	{
 		.name = "C1-IVB",
 		.desc = "MWAIT 0x00",
@@ -236,7 +236,7 @@ static struct cpuidle_state ivb_cstates[CPUIDLE_STATE_MAX] = {
 		.enter = NULL }
 };
 
-static struct cpuidle_state hsw_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state hsw_cstates[] = {
 	{
 		.name = "C1-HSW",
 		.desc = "MWAIT 0x00",
@@ -297,7 +297,7 @@ static struct cpuidle_state hsw_cstates[CPUIDLE_STATE_MAX] = {
 		.enter = NULL }
 };
 
-static struct cpuidle_state atom_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state atom_cstates[] = {
 	{
 		.name = "C1E-ATM",
 		.desc = "MWAIT 0x00",
@@ -628,7 +628,7 @@ static int intel_idle_cpu_init(int cpu)
 		int num_substates, mwait_hint, mwait_cstate, mwait_substate;
 
 		if (cpuidle_state_table[cstate].enter == NULL)
-			continue;
+			break;
 
 		if (cstate + 1 > max_cstate) {
 			printk(PREFIX "max_cstate %d reached\n", max_cstate);
Signature · 1 line
1.8.2.3
#1 lore raw
Quoted 4 lines · Bartlomiej Zolnierkiewicz

There is no reason to define CPUIDLE_STATE_MAX (currently 10) entries in states tables if the driver always stops iterating over table when it encounters first .enter == NULL entry.

Quoted 8 lines
$ size drivers/idle/intel_idle.o.*
   text    data     bss     dec     hex filename
   2886    5440      32    8358    20a6 drivers/idle/intel_idle.o.before
   2886    3752      32    6670    1a0e drivers/idle/intel_idle.o.after

Thanks, I'll queue this series up for 3.13.

Quoted 63 lines
---
 drivers/idle/intel_idle.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
drivers/idle/intel_idle.c +6 -6
index fa6964d..9c97fbb42 100644
@@ -123,7 +123,7 @@ static struct cpuidle_state *cpuidle_state_table;
  * which is also the index into the MWAIT hint array.
  * Thus C0 is a dummy.
  */
-static struct cpuidle_state nehalem_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state nehalem_cstates[] = {
 	{
 		.name = "C1-NHM",
 		.desc = "MWAIT 0x00",
@@ -156,7 +156,7 @@ static struct cpuidle_state nehalem_cstates[CPUIDLE_STATE_MAX] = {
 		.enter = NULL }
 };
 
-static struct cpuidle_state snb_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state snb_cstates[] = {
 	{
 		.name = "C1-SNB",
 		.desc = "MWAIT 0x00",
@@ -196,7 +196,7 @@ static struct cpuidle_state snb_cstates[CPUIDLE_STATE_MAX] = {
 		.enter = NULL }
 };
 
-static struct cpuidle_state ivb_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state ivb_cstates[] = {
 	{
 		.name = "C1-IVB",
 		.desc = "MWAIT 0x00",
@@ -236,7 +236,7 @@ static struct cpuidle_state ivb_cstates[CPUIDLE_STATE_MAX] = {
 		.enter = NULL }
 };
 
-static struct cpuidle_state hsw_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state hsw_cstates[] = {
 	{
 		.name = "C1-HSW",
 		.desc = "MWAIT 0x00",
@@ -297,7 +297,7 @@ static struct cpuidle_state hsw_cstates[CPUIDLE_STATE_MAX] = {
 		.enter = NULL }
 };
 
-static struct cpuidle_state atom_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state atom_cstates[] = {
 	{
 		.name = "C1E-ATM",
 		.desc = "MWAIT 0x00",
@@ -628,7 +628,7 @@ static int intel_idle_cpu_init(int cpu)
 		int num_substates, mwait_hint, mwait_cstate, mwait_substate;
 
 		if (cpuidle_state_table[cstate].enter == NULL)
-			continue;
+			break;
 
 		if (cstate + 1 > max_cstate) {
 			printk(PREFIX "max_cstate %d reached\n", max_cstate);
Signature · 2 lines
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
Acked-by on v1 1/3
#2 lore raw
In reply to Bartlomiej Zolnierkiewicz
Quoted 9 lines · Bartlomiej Zolnierkiewicz

There is no reason to define CPUIDLE_STATE_MAX (currently 10) entries in states tables if the driver always stops iterating over table when it encounters first .enter == NULL entry.

$ size drivers/idle/intel_idle.o.*
   text    data     bss     dec     hex filename
   2886    5440      32    8358    20a6 drivers/idle/intel_idle.o.before
   2886    3752      32    6670    1a0e drivers/idle/intel_idle.o.after
Quoted 4 lines

---

Quoted 62 lines
 drivers/idle/intel_idle.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
drivers/idle/intel_idle.c +6 -6
index fa6964d..9c97fbb42 100644
@@ -123,7 +123,7 @@ static struct cpuidle_state *cpuidle_state_table;
  * which is also the index into the MWAIT hint array.
  * Thus C0 is a dummy.
  */
-static struct cpuidle_state nehalem_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state nehalem_cstates[] = {
 	{
 		.name = "C1-NHM",
 		.desc = "MWAIT 0x00",
@@ -156,7 +156,7 @@ static struct cpuidle_state nehalem_cstates[CPUIDLE_STATE_MAX] = {
 		.enter = NULL }
 };
 
-static struct cpuidle_state snb_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state snb_cstates[] = {
 	{
 		.name = "C1-SNB",
 		.desc = "MWAIT 0x00",
@@ -196,7 +196,7 @@ static struct cpuidle_state snb_cstates[CPUIDLE_STATE_MAX] = {
 		.enter = NULL }
 };
 
-static struct cpuidle_state ivb_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state ivb_cstates[] = {
 	{
 		.name = "C1-IVB",
 		.desc = "MWAIT 0x00",
@@ -236,7 +236,7 @@ static struct cpuidle_state ivb_cstates[CPUIDLE_STATE_MAX] = {
 		.enter = NULL }
 };
 
-static struct cpuidle_state hsw_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state hsw_cstates[] = {
 	{
 		.name = "C1-HSW",
 		.desc = "MWAIT 0x00",
@@ -297,7 +297,7 @@ static struct cpuidle_state hsw_cstates[CPUIDLE_STATE_MAX] = {
 		.enter = NULL }
 };
 
-static struct cpuidle_state atom_cstates[CPUIDLE_STATE_MAX] = {
+static struct cpuidle_state atom_cstates[] = {
 	{
 		.name = "C1E-ATM",
 		.desc = "MWAIT 0x00",
@@ -628,7 +628,7 @@ static int intel_idle_cpu_init(int cpu)
 		int num_substates, mwait_hint, mwait_cstate, mwait_substate;
 
 		if (cpuidle_state_table[cstate].enter == NULL)
-			continue;
+			break;
 
 		if (cstate + 1 > max_cstate) {
 			printk(PREFIX "max_cstate %d reached\n", max_cstate);
Signature · 5 lines
 <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog