2008-10-09 08:21:49

by bibo, mao

Subject: [patch 1/1] combine two adjacent mtrr region with the same type

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 <[email protected]>

-------------------------------------------------------------------------------
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"

2008-10-09 15:55:11

by Yinghai Lu

Subject: Re: [patch 1/1] combine two adjacent mtrr region with the same type

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 <[email protected]>
>
> -------------------------------------------------------------------------------
> 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

2008-10-10 04:00:51

by bmao

Subject: Re: [patch 1/1] combine two adjacent mtrr region with the same type

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 <[email protected]>
>>
>> -------------------------------------------------------------------------------
>> 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