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* [patch 1/1] combine two adjacent mtrr region with the same type
@ 2008-10-09  8:21 bibo mao
  2008-10-09 15:54 ` Yinghai Lu
  0 siblings, 1 reply; 3+ messages in thread
From: bibo mao @ 2008-10-09  8:21 UTC (permalink / raw)
  To: linux-kernel; +Cc: akpm

This patch is to combine two adjacent mtrr region with the same type.

 kernel/cpu/mtrr/main.c          |   17 +++++++++++++++--
 3 files changed, 15 insertions(+), 2 deletions(-)

Signed-off-by: bibo mao <bibo.mao@gmail.com>

-------------------------------------------------------------------------------
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 6e212f3..c3adf83 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -305,7 +305,7 @@ int mtrr_add_page(unsigned long base, unsigned long size,
 {
 	int i, j, replace, error;
 	mtrr_type ltype;
-	unsigned long lbase, lsize;
+	unsigned long lbase, lsize, newbase;

 	if (!mtrr_if)
 		return -ENXIO;
@@ -344,7 +344,7 @@ int mtrr_add_page(unsigned long base, unsigned long size,
 	mutex_lock(&mtrr_mutex);
 	for (i = 0; i < num_var_ranges; ++i) {
 		mtrr_if->get(i, &lbase, &lsize, &ltype);
-		if (!lsize || base > lbase + lsize - 1 || base + size - 1 < lbase)
+		if (!lsize || base > lbase + lsize || base + size < lbase)
 			continue;
 		/*  At this point we know there is some kind of overlap/enclosure  */
 		if (base < lbase || base + size - 1 > lbase + lsize - 1) {
@@ -356,6 +356,19 @@ int mtrr_add_page(unsigned long base, unsigned long size,
 				}
 				else if (types_compatible(type, ltype))
 					continue;
+			} else if ((base == lbase + lsize) || (lbase ==base + size)) {
+				if (type != ltype)
+					continue;
+				/* New region adjacent with an existing region  */
+				newbase = (base < lbase) ? base : lbase;
+				if (!mtrr_if->validate_add_page(newbase,lsize + size,type) &&
+				   mtrr_if->get_free_region(newbase, lsize + size, replace)>=0) {
+					base = newbase;
+					size += lsize;
+					replace = i;
+					continue;
+				} else
+					continue;
 			}
 			printk(KERN_WARNING
 			       "mtrr: 0x%lx000,0x%lx000 overlaps existing"

^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [patch 1/1] combine two adjacent mtrr region with the same type
  2008-10-09  8:21 [patch 1/1] combine two adjacent mtrr region with the same type bibo mao
@ 2008-10-09 15:54 ` Yinghai Lu
  2008-10-10  3:59   ` bmao
  0 siblings, 1 reply; 3+ messages in thread
From: Yinghai Lu @ 2008-10-09 15:54 UTC (permalink / raw)
  To: bibo mao; +Cc: linux-kernel, akpm

bibo mao wrote:
> This patch is to combine two adjacent mtrr region with the same type.
> 
>  kernel/cpu/mtrr/main.c          |   17 +++++++++++++++--
>  3 files changed, 15 insertions(+), 2 deletions(-)
> 
> Signed-off-by: bibo mao <bibo.mao@gmail.com>
> 
> -------------------------------------------------------------------------------
> diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
> index 6e212f3..c3adf83 100644
> --- a/arch/x86/kernel/cpu/mtrr/main.c
> +++ b/arch/x86/kernel/cpu/mtrr/main.c
> @@ -305,7 +305,7 @@ int mtrr_add_page(unsigned long base, unsigned long size,
>  {
>  	int i, j, replace, error;
>  	mtrr_type ltype;
> -	unsigned long lbase, lsize;
> +	unsigned long lbase, lsize, newbase;
> 
>  	if (!mtrr_if)
>  		return -ENXIO;
> @@ -344,7 +344,7 @@ int mtrr_add_page(unsigned long base, unsigned long size,
>  	mutex_lock(&mtrr_mutex);
>  	for (i = 0; i < num_var_ranges; ++i) {
>  		mtrr_if->get(i, &lbase, &lsize, &ltype);
> -		if (!lsize || base > lbase + lsize - 1 || base + size - 1 < lbase)
> +		if (!lsize || base > lbase + lsize || base + size < lbase)
>  			continue;
>  		/*  At this point we know there is some kind of overlap/enclosure  */
>  		if (base < lbase || base + size - 1 > lbase + lsize - 1) {
> @@ -356,6 +356,19 @@ int mtrr_add_page(unsigned long base, unsigned long size,
>  				}
>  				else if (types_compatible(type, ltype))
>  					continue;
> +			} else if ((base == lbase + lsize) || (lbase ==base + size)) {
> +				if (type != ltype)
> +					continue;
this path seems not right...

do you need

                if (ltype != type) {
                        if (types_compatible(type, ltype))
                                continue;
                        printk (KERN_WARNING "mtrr: type mismatch for %lx000,%lx000 old: %s new: %s\n",
                             base, size, mtrr_attrib_to_str(ltype),
                             mtrr_attrib_to_str(type));
                        goto out;
                }
?




> +				/* New region adjacent with an existing region  */
> +				newbase = (base < lbase) ? base : lbase;
> +				if (!mtrr_if->validate_add_page(newbase,lsize + size,type) &&
> +				   mtrr_if->get_free_region(newbase, lsize + size, replace)>=0) {
> +					base = newbase;
> +					size += lsize;
> +					replace = i;
> +					continue;
> +				} else
> +					continue;
>  			}
>  			printk(KERN_WARNING
>  			       "mtrr: 0x%lx000,0x%lx000 overlaps existing"

better to have some test case...

YH

^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [patch 1/1] combine two adjacent mtrr region with the same type
  2008-10-09 15:54 ` Yinghai Lu
@ 2008-10-10  3:59   ` bmao
  0 siblings, 0 replies; 3+ messages in thread
From: bmao @ 2008-10-10  3:59 UTC (permalink / raw)
  To: Yinghai Lu; +Cc: bibo mao, linux-kernel, akpm

Yinghai Lu wrote:
> bibo mao wrote:
>> This patch is to combine two adjacent mtrr region with the same type.
>>
>>  kernel/cpu/mtrr/main.c          |   17 +++++++++++++++--
>>  3 files changed, 15 insertions(+), 2 deletions(-)
>>
>> Signed-off-by: bibo mao <bibo.mao@gmail.com>
>>
>> -------------------------------------------------------------------------------
>> diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
>> index 6e212f3..c3adf83 100644
>> --- a/arch/x86/kernel/cpu/mtrr/main.c
>> +++ b/arch/x86/kernel/cpu/mtrr/main.c
>> @@ -305,7 +305,7 @@ int mtrr_add_page(unsigned long base, unsigned long size,
>>  {
>>       int i, j, replace, error;
>>       mtrr_type ltype;
>> -     unsigned long lbase, lsize;
>> +     unsigned long lbase, lsize, newbase;
>>
>>       if (!mtrr_if)
>>               return -ENXIO;
>> @@ -344,7 +344,7 @@ int mtrr_add_page(unsigned long base, unsigned long size,
>>       mutex_lock(&mtrr_mutex);
>>       for (i = 0; i < num_var_ranges; ++i) {
>>               mtrr_if->get(i, &lbase, &lsize, &ltype);
>> -             if (!lsize || base > lbase + lsize - 1 || base + size - 1 < lbase)
>> +             if (!lsize || base > lbase + lsize || base + size < lbase)
>>                       continue;
>>               /*  At this point we know there is some kind of overlap/enclosure  */
>>               if (base < lbase || base + size - 1 > lbase + lsize - 1) {
>> @@ -356,6 +356,19 @@ int mtrr_add_page(unsigned long base, unsigned long size,
>>                               }
>>                               else if (types_compatible(type, ltype))
>>                                       continue;
>> +                     } else if ((base == lbase + lsize) || (lbase ==base + size)) {
>> +                             if (type != ltype)
>> +                                     continue;
> this path seems not right...
> 
> do you need
> 
>                 if (ltype != type) {
>                         if (types_compatible(type, ltype))
>                                 continue;
>                         printk (KERN_WARNING "mtrr: type mismatch for %lx000,%lx000 old: %s new: %s\n",
>                              base, size, mtrr_attrib_to_str(ltype),
>                              mtrr_attrib_to_str(type));
>                         goto out;
>                 }
> ?
This warning info is for two enclosed mtrr region, but it is adjacent here. Here is no overlapped mtrr region even.
> 
> 
> 
> 
>> +                             /* New region adjacent with an existing region  */
>> +                             newbase = (base < lbase) ? base : lbase;
>> +                             if (!mtrr_if->validate_add_page(newbase,lsize + size,type) &&
>> +                                mtrr_if->get_free_region(newbase, lsize + size, replace)>=0) {
>> +                                     base = newbase;
>> +                                     size += lsize;
>> +                                     replace = i;
>> +                                     continue;
>> +                             } else
>> +                                     continue;
>>                       }
>>                       printk(KERN_WARNING
>>                              "mtrr: 0x%lx000,0x%lx000 overlaps existing"
> 
> better to have some test case...
> 
> YH
> 
Here is test result: 

# echo "base=0x02000000 size=0x00800000 type=write-back" >| /proc/mtrr
# echo "base=0x03000000 size=0x01000000 type=write-back" >| /proc/mtrr
# cat /proc/mtrr 
reg00: base=0x02000000 (  32MB), size=   8MB: write-back, count=1
reg01: base=0x03000000 (  48MB), size=  16MB: write-back, count=1

# echo "base=0x02800000 size=0x00800000 type=write-back" >| /proc/mtrr
# cat /proc/mtrr 
reg01: base=0x02000000 (  32MB), size=  32MB: write-back, count=3

Without this patch, it will display with this result:

reg00: base=0x02000000 (  32MB), size=   8MB: write-back, count=1
reg01: base=0x03000000 (  48MB), size=  16MB: write-back, count=1
reg02: base=0x02800000 (  40MB), size=   8MB: write-back, count=1

thanks
bibo,mao

^ permalink raw reply	[flat|nested] 3+ messages in thread
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2008-10-09  8:21 [patch 1/1] combine two adjacent mtrr region with the same type bibo mao
2008-10-09 15:54 ` Yinghai Lu
2008-10-10  3:59   ` bmao

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