diff mbox

realtek: rtl8xxxu: Use const init arrays

Message ID 459bf15427d92cd052fb2fe080438fd97a8a6cd8.1475343483.git.joe@perches.com (mailing list archive)
State Not Applicable
Delegated to: Kalle Valo
Headers show

Commit Message

Joe Perches Oct. 1, 2016, 5:39 p.m. UTC 
Make the init arrays const to reduce data.

$ size drivers/net/wireless/realtek/rtl8xxxu/built-in.o* (allyesconfig: x86-32)
   text	   data	    bss	    dec	    hex	filename
  80107	  13651	     58	  93816	  16e78	drivers/net/wireless/realtek/rtl8xxxu/built-in.o.new
  65303	  28435	     58	  93796	  16e64	drivers/net/wireless/realtek/rtl8xxxu/built-in.o.old

Signed-off-by: Joe Perches <joe@perches.com>
---
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h       |  6 +++---
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8192e.c |  8 ++++----
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c |  6 +++---
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c  | 16 ++++++++--------
 4 files changed, 18 insertions(+), 18 deletions(-)

Comments

Jes Sorensen Oct. 1, 2016, 6:53 p.m. UTC | #1 
Joe Perches <joe@perches.com> writes:
> Make the init arrays const to reduce data.
>
> $ size drivers/net/wireless/realtek/rtl8xxxu/built-in.o* (allyesconfig: x86-32)
>    text	   data	    bss	    dec	    hex	filename
>   80107	  13651	     58	  93816	  16e78	drivers/net/wireless/realtek/rtl8xxxu/built-in.o.new
>   65303	  28435	     58	  93796	  16e64	drivers/net/wireless/realtek/rtl8xxxu/built-in.o.old
>
> Signed-off-by: Joe Perches <joe@perches.com>

In total you grow the kernel by 20 bytes. You reduce the data segment
substantially while growing the text segment instead.

If any architecture replicates the text segment onto individual numa
nodes, this would actually be a real loss rather than a win. Some archs
used to do this, not sure if they are doing it anymore.

I am not against this patch, but I am not sure it's really a win either.

Jes
Joe Perches Oct. 1, 2016, 8 p.m. UTC | #2 
On Sat, 2016-10-01 at 14:53 -0400, Jes Sorensen wrote:
> Joe Perches <joe@perches.com> writes:
> > Make the init arrays const to reduce data.
> > $ size drivers/net/wireless/realtek/rtl8xxxu/built-in.o* (allyesconfig: x86-32)
> >    text	   data	    bss	    dec	    hex	filename
> >   80107	  13651	     58	  93816	  16e78	drivers/net/wireless/realtek/rtl8xxxu/built-in.o.new
> >   65303	  28435	     58	  93796	  16e64	drivers/net/wireless/realtek/rtl8xxxu/built-in.o.old
> In total you grow the kernel by 20 bytes. You reduce the data segment
> substantially while growing the text segment instead.

No, not really.   The alignment boundaries move a bit for
this particular compilation.  It could go the other way for
a different compiler version or set of CONFIG options.

What's important is multiple pages of .data move to .rodata.
Jes Sorensen Oct. 1, 2016, 8:32 p.m. UTC | #3 
Joe Perches <joe@perches.com> writes:
> On Sat, 2016-10-01 at 14:53 -0400, Jes Sorensen wrote:
>> Joe Perches <joe@perches.com> writes:
>> > Make the init arrays const to reduce data.
>> > $ size drivers/net/wireless/realtek/rtl8xxxu/built-in.o*
>> > (allyesconfig: x86-32)
>> >    text	   data	    bss	    dec	    hex	filename
>> >   80107 13651 58 93816 16e78
>> > drivers/net/wireless/realtek/rtl8xxxu/built-in.o.new
>> >   65303 28435 58 93796 16e64
>> > drivers/net/wireless/realtek/rtl8xxxu/built-in.o.old
>> In total you grow the kernel by 20 bytes. You reduce the data segment
>> substantially while growing the text segment instead.
>
> No, not really.   The alignment boundaries move a bit for
> this particular compilation.  It could go the other way for
> a different compiler version or set of CONFIG options.
>
> What's important is multiple pages of .data move to .rodata.

Your output shows it moving to the text segment - if it's in a different
segment, eg. rodata, you should use output demonstrating that to justify
the change.

Jes
Joe Perches Oct. 1, 2016, 9:08 p.m. UTC | #4 
On Sat, 2016-10-01 at 16:32 -0400, Jes Sorensen wrote:
> Your output shows it moving to the text segment - if it's in a different
> segment, eg. rodata, you should use output demonstrating that to justify
> the change.

For size, rodata _is_ text
Jes Sorensen Oct. 1, 2016, 11:20 p.m. UTC | #5 
Joe Perches <joe@perches.com> writes:
> On Sat, 2016-10-01 at 16:32 -0400, Jes Sorensen wrote:
>> Your output shows it moving to the text segment - if it's in a different
>> segment, eg. rodata, you should use output demonstrating that to justify
>> the change.
>
> For size, rodata _is_ text

Well then maybe use something which provides accurate data.

Jes
diff mbox

Patch

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
index 1016628926d2..bd4449704dfa 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
@@ -1355,7 +1355,7 @@  struct rtl8xxxu_fileops {
 	u16 trxff_boundary;
 	u8 pbp_rx;
 	u8 pbp_tx;
-	struct rtl8xxxu_reg8val *mactable;
+	const struct rtl8xxxu_reg8val *mactable;
 	u8 total_page_num;
 	u8 page_num_hi;
 	u8 page_num_lo;
@@ -1364,7 +1364,7 @@  struct rtl8xxxu_fileops {
 
 extern int rtl8xxxu_debug;
 
-extern struct rtl8xxxu_reg8val rtl8xxxu_gen1_mac_init_table[];
+extern const struct rtl8xxxu_reg8val rtl8xxxu_gen1_mac_init_table[];
 extern const u32 rtl8xxxu_iqk_phy_iq_bb_reg[];
 u8 rtl8xxxu_read8(struct rtl8xxxu_priv *priv, u16 addr);
 u16 rtl8xxxu_read16(struct rtl8xxxu_priv *priv, u16 addr);
@@ -1396,7 +1396,7 @@  int rtl8xxxu_init_phy_rf(struct rtl8xxxu_priv *priv,
 			 struct rtl8xxxu_rfregval *table,
 			 enum rtl8xxxu_rfpath path);
 int rtl8xxxu_init_phy_regs(struct rtl8xxxu_priv *priv,
-			   struct rtl8xxxu_reg32val *array);
+			   const struct rtl8xxxu_reg32val *array);
 int rtl8xxxu_load_firmware(struct rtl8xxxu_priv *priv, char *fw_name);
 void rtl8xxxu_firmware_self_reset(struct rtl8xxxu_priv *priv);
 void rtl8xxxu_power_off(struct rtl8xxxu_priv *priv);
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8192e.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8192e.c
index df54d27e7851..934a380f09b1 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8192e.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8192e.c
@@ -40,7 +40,7 @@ 
 #include "rtl8xxxu.h"
 #include "rtl8xxxu_regs.h"
 
-static struct rtl8xxxu_reg8val rtl8192e_mac_init_table[] = {
+static const struct rtl8xxxu_reg8val rtl8192e_mac_init_table[] = {
 	{0x011, 0xeb}, {0x012, 0x07}, {0x014, 0x75}, {0x303, 0xa7},
 	{0x428, 0x0a}, {0x429, 0x10}, {0x430, 0x00}, {0x431, 0x00},
 	{0x432, 0x00}, {0x433, 0x01}, {0x434, 0x04}, {0x435, 0x05},
@@ -70,7 +70,7 @@  static struct rtl8xxxu_reg8val rtl8192e_mac_init_table[] = {
 	{0xffff, 0xff},
 };
 
-static struct rtl8xxxu_reg32val rtl8192eu_phy_init_table[] = {
+static const struct rtl8xxxu_reg32val rtl8192eu_phy_init_table[] = {
 	{0x800, 0x80040000}, {0x804, 0x00000003},
 	{0x808, 0x0000fc00}, {0x80c, 0x0000000a},
 	{0x810, 0x10001331}, {0x814, 0x020c3d10},
@@ -202,7 +202,7 @@  static struct rtl8xxxu_reg32val rtl8192eu_phy_init_table[] = {
 	{0xffff, 0xffffffff},
 };
 
-static struct rtl8xxxu_reg32val rtl8xxx_agc_8192eu_std_table[] = {
+static const struct rtl8xxxu_reg32val rtl8xxx_agc_8192eu_std_table[] = {
 	{0xc78, 0xfb000001}, {0xc78, 0xfb010001},
 	{0xc78, 0xfb020001}, {0xc78, 0xfb030001},
 	{0xc78, 0xfb040001}, {0xc78, 0xfb050001},
@@ -271,7 +271,7 @@  static struct rtl8xxxu_reg32val rtl8xxx_agc_8192eu_std_table[] = {
 	{0xffff, 0xffffffff}
 };
 
-static struct rtl8xxxu_reg32val rtl8xxx_agc_8192eu_highpa_table[] = {
+static const struct rtl8xxxu_reg32val rtl8xxx_agc_8192eu_highpa_table[] = {
 	{0xc78, 0xfa000001}, {0xc78, 0xf9010001},
 	{0xc78, 0xf8020001}, {0xc78, 0xf7030001},
 	{0xc78, 0xf6040001}, {0xc78, 0xf5050001},
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c
index 6c086b5657e9..3f173b67fc0d 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c
@@ -40,7 +40,7 @@ 
 #include "rtl8xxxu.h"
 #include "rtl8xxxu_regs.h"
 
-static struct rtl8xxxu_reg8val rtl8723b_mac_init_table[] = {
+static const struct rtl8xxxu_reg8val rtl8723b_mac_init_table[] = {
 	{0x02f, 0x30}, {0x035, 0x00}, {0x039, 0x08}, {0x04e, 0xe0},
 	{0x064, 0x00}, {0x067, 0x20}, {0x428, 0x0a}, {0x429, 0x10},
 	{0x430, 0x00}, {0x431, 0x00},
@@ -71,7 +71,7 @@  static struct rtl8xxxu_reg8val rtl8723b_mac_init_table[] = {
 	{0xffff, 0xff},
 };
 
-static struct rtl8xxxu_reg32val rtl8723b_phy_1t_init_table[] = {
+static const struct rtl8xxxu_reg32val rtl8723b_phy_1t_init_table[] = {
 	{0x800, 0x80040000}, {0x804, 0x00000003},
 	{0x808, 0x0000fc00}, {0x80c, 0x0000000a},
 	{0x810, 0x10001331}, {0x814, 0x020c3d10},
@@ -172,7 +172,7 @@  static struct rtl8xxxu_reg32val rtl8723b_phy_1t_init_table[] = {
 	{0xffff, 0xffffffff},
 };
 
-static struct rtl8xxxu_reg32val rtl8xxx_agc_8723bu_table[] = {
+static const struct rtl8xxxu_reg32val rtl8xxx_agc_8723bu_table[] = {
 	{0xc78, 0xfd000001}, {0xc78, 0xfc010001},
 	{0xc78, 0xfb020001}, {0xc78, 0xfa030001},
 	{0xc78, 0xf9040001}, {0xc78, 0xf8050001},
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index b2d7f6e69667..7c62293948cb 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -135,7 +135,7 @@  static struct ieee80211_supported_band rtl8xxxu_supported_band = {
 	.n_bitrates = ARRAY_SIZE(rtl8xxxu_rates),
 };
 
-struct rtl8xxxu_reg8val rtl8xxxu_gen1_mac_init_table[] = {
+const struct rtl8xxxu_reg8val rtl8xxxu_gen1_mac_init_table[] = {
 	{0x420, 0x80}, {0x423, 0x00}, {0x430, 0x00}, {0x431, 0x00},
 	{0x432, 0x00}, {0x433, 0x01}, {0x434, 0x04}, {0x435, 0x05},
 	{0x436, 0x06}, {0x437, 0x07}, {0x438, 0x00}, {0x439, 0x00},
@@ -160,7 +160,7 @@  struct rtl8xxxu_reg8val rtl8xxxu_gen1_mac_init_table[] = {
 	{0x70a, 0x65}, {0x70b, 0x87}, {0xffff, 0xff},
 };
 
-static struct rtl8xxxu_reg32val rtl8723a_phy_1t_init_table[] = {
+static const struct rtl8xxxu_reg32val rtl8723a_phy_1t_init_table[] = {
 	{0x800, 0x80040000}, {0x804, 0x00000003},
 	{0x808, 0x0000fc00}, {0x80c, 0x0000000a},
 	{0x810, 0x10001331}, {0x814, 0x020c3d10},
@@ -258,7 +258,7 @@  static struct rtl8xxxu_reg32val rtl8723a_phy_1t_init_table[] = {
 	{0xffff, 0xffffffff},
 };
 
-static struct rtl8xxxu_reg32val rtl8192cu_phy_2t_init_table[] = {
+static const struct rtl8xxxu_reg32val rtl8192cu_phy_2t_init_table[] = {
 	{0x024, 0x0011800f}, {0x028, 0x00ffdb83},
 	{0x800, 0x80040002}, {0x804, 0x00000003},
 	{0x808, 0x0000fc00}, {0x80c, 0x0000000a},
@@ -356,7 +356,7 @@  static struct rtl8xxxu_reg32val rtl8192cu_phy_2t_init_table[] = {
 	{0xffff, 0xffffffff},
 };
 
-static struct rtl8xxxu_reg32val rtl8188ru_phy_1t_highpa_table[] = {
+static const struct rtl8xxxu_reg32val rtl8188ru_phy_1t_highpa_table[] = {
 	{0x024, 0x0011800f}, {0x028, 0x00ffdb83},
 	{0x040, 0x000c0004}, {0x800, 0x80040000},
 	{0x804, 0x00000001}, {0x808, 0x0000fc00},
@@ -455,7 +455,7 @@  static struct rtl8xxxu_reg32val rtl8188ru_phy_1t_highpa_table[] = {
 	{0xffff, 0xffffffff},
 };
 
-static struct rtl8xxxu_reg32val rtl8xxx_agc_standard_table[] = {
+static const struct rtl8xxxu_reg32val rtl8xxx_agc_standard_table[] = {
 	{0xc78, 0x7b000001}, {0xc78, 0x7b010001},
 	{0xc78, 0x7b020001}, {0xc78, 0x7b030001},
 	{0xc78, 0x7b040001}, {0xc78, 0x7b050001},
@@ -539,7 +539,7 @@  static struct rtl8xxxu_reg32val rtl8xxx_agc_standard_table[] = {
 	{0xffff, 0xffffffff}
 };
 
-static struct rtl8xxxu_reg32val rtl8xxx_agc_highpa_table[] = {
+static const struct rtl8xxxu_reg32val rtl8xxx_agc_highpa_table[] = {
 	{0xc78, 0x7b000001}, {0xc78, 0x7b010001},
 	{0xc78, 0x7b020001}, {0xc78, 0x7b030001},
 	{0xc78, 0x7b040001}, {0xc78, 0x7b050001},
@@ -2146,7 +2146,7 @@  void rtl8xxxu_firmware_self_reset(struct rtl8xxxu_priv *priv)
 static int
 rtl8xxxu_init_mac(struct rtl8xxxu_priv *priv)
 {
-	struct rtl8xxxu_reg8val *array = priv->fops->mactable;
+	const struct rtl8xxxu_reg8val *array = priv->fops->mactable;
 	int i, ret;
 	u16 reg;
 	u8 val;
@@ -2174,7 +2174,7 @@  rtl8xxxu_init_mac(struct rtl8xxxu_priv *priv)
 }
 
 int rtl8xxxu_init_phy_regs(struct rtl8xxxu_priv *priv,
-			   struct rtl8xxxu_reg32val *array)
+			   const struct rtl8xxxu_reg32val *array)
 {
 	int i, ret;
 	u16 reg;