Re: [PATCH] free e820 reserved memory in bootargs memmap

[zoucao-ipc]

I found commit characters errors, please ignore this path, V2 will be 
sent soon


On 2018/4/8 下午2:41, zou...@linux.alibaba.com wrote:

add a new chareater "-" in bootargs memmap, you can use this chareater to free
e820 reserved memory, for example:

reserved iomem:
cat /proc/iomem:
..
0010-6aefefff : System RAM
  0100-0165537a : Kernel code
  0165537b-01a8873f : Kernel data
  01c31000-01f4efff : Kernel bss
  2800-320f : Crash kernel
6aeff000-6eff : reserved   --> it is e820 reserved memory
6f00-78240fff : System RAM
..


add bootargs memmap=0x4101000-0x6aeff000, to free memory region: 
6aeff000-6eff
then 6aeff000-6eff will be merged into 0010-78240fff.

new iomem:
cat /proc/iomem:
..
0010-78240fff : System RAM
  0100-0165537a : Kernel code
  0165537b-01a8873f : Kernel data
  01c31000-01f4efff : Kernel bss
..

Re: [PATCH] x86/boot/e820: add new chareater "-" to free BIOS memory in memmap bootargs

[zoucao-ipc]

ping?

On 2018/4/10 上午10:59, zou...@linux.alibaba.com wrote:

From: zoucao 

Normally every BIOS reserved memory is used for some features, we can't
use them, but in some conditions,  users can ensure some BIOS memories
are not used and reserved memory is well to free, they have not a good
way to free these memories, here add a new chareater "-" in memmap to
free reserved memory.

Signed-off-by: zou cao 
---
  7u/Documentation/kernel-parameters.txt | 6 ++
  7u/arch/x86/kernel/e820.c  | 3 +++
  2 files changed, 9 insertions(+)

diff --git a/7u/Documentation/kernel-parameters.txt 
b/7u/Documentation/kernel-parameters.txt
index 9a1abb99a..dbea75e12 100644
--- a/7u/Documentation/kernel-parameters.txt
+++ b/7u/Documentation/kernel-parameters.txt
@@ -1677,6 +1677,12 @@ bytes respectively. Such letter suffixes can also be 
entirely omitted.
 or
 memmap=0x1$0x1869
  
+	memmap=nn[KMG]-ss[KMG]

+   Free E820 reserved memory, as specified by the user.
+   Region of reserved memory to be free, from ss to ss+nn.
+   Example: free reserved memory from 0x1869-0x186a
+   memmap=0x4101000-0x6aeff000
+
memory_corruption_check=0/1 [X86]
Some BIOSes seem to corrupt the first 64k of
memory when doing things like suspend/resume.
diff --git a/7u/arch/x86/kernel/e820.c b/7u/arch/x86/kernel/e820.c
index 174da5fc5..b8a042981 100644
--- a/7u/arch/x86/kernel/e820.c
+++ b/7u/arch/x86/kernel/e820.c
@@ -875,6 +875,9 @@ static int __init parse_memmap_one(char *p)
} else if (*p == '$') {
start_at = memparse(p+1, );
e820_add_region(start_at, mem_size, E820_RESERVED);
+   } else if (*p == '-') {
+   start_at = memparse(p+1, );
+   e820_remove_range(start_at, mem_size, E820_RESERVED, E820_RAM);
} else
e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
  

Re: [PATCH] x86/boot/e820: add new chareater "-" to free BIOS memory in memmap bootargs

[zoucao-ipc]

On 2018/4/17 下午9:47, Thomas Gleixner wrote:

On Tue, 10 Apr 2018, zou...@linux.alibaba.com wrote:

From: zoucao 

Interesting from ... Please use your real mail address for this.

miss this, i will do it.

Normally every BIOS reserved memory is used for some features, we can't
use them, but in some conditions,  users can ensure some BIOS memories
are not used and reserved memory is well to free, they have not a good
way to free these memories, here add a new chareater "-" in memmap to
free reserved memory.

I'm not really convinced about this. How should anyone without detailed
BIOS knowledge know that this is really reusable?

The person who knows must have access to the BIOS developer, so why can't
the BIOS be fixed instead?

Thanks,

tglx


Signed-off-by: zou cao 
---
  7u/Documentation/kernel-parameters.txt | 6 ++
  7u/arch/x86/kernel/e820.c  | 3 +++
  2 files changed, 9 insertions(+)

diff --git a/7u/Documentation/kernel-parameters.txt 
b/7u/Documentation/kernel-parameters.txt
index 9a1abb99a..dbea75e12 100644
--- a/7u/Documentation/kernel-parameters.txt
+++ b/7u/Documentation/kernel-parameters.txt
@@ -1677,6 +1677,12 @@ bytes respectively. Such letter suffixes can also be 
entirely omitted.
 or
 memmap=0x1$0x1869
  
+	memmap=nn[KMG]-ss[KMG]

+   Free E820 reserved memory, as specified by the user.
+   Region of reserved memory to be free, from ss to ss+nn.
+   Example: free reserved memory from 0x1869-0x186a
+   memmap=0x4101000-0x6aeff000
+
memory_corruption_check=0/1 [X86]
Some BIOSes seem to corrupt the first 64k of
memory when doing things like suspend/resume.
diff --git a/7u/arch/x86/kernel/e820.c b/7u/arch/x86/kernel/e820.c
index 174da5fc5..b8a042981 100644
--- a/7u/arch/x86/kernel/e820.c
+++ b/7u/arch/x86/kernel/e820.c
@@ -875,6 +875,9 @@ static int __init parse_memmap_one(char *p)
} else if (*p == '$') {
start_at = memparse(p+1, );
e820_add_region(start_at, mem_size, E820_RESERVED);
+   } else if (*p == '-') {
+   start_at = memparse(p+1, );
+   e820_remove_range(start_at, mem_size, E820_RESERVED, E820_RAM);
} else
e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
  
--

2.14.1.40.g8e62ba1

Re: [PATCH] x86/boot/e820: add new chareater "-" to free BIOS memory in memmap bootargs

[zoucao-ipc]

Hi thomas:

Sorry, i don't receive yesterday email, i think the ping email is lost,
so bad me.
Anyway，have you some suggestions for this little patch? i really need 
your help.


Regards,
czou

On 2018/4/17 下午6:22, Thomas Gleixner wrote:

On Tue, 17 Apr 2018, zoucao-ipc wrote:


ping?

You already pinged yesterday. Are you going to switch to hourly pings
tomorrow?

Re: [PATCH] x86/boot/e820: add new chareater "-" to free BIOS memory in memmap bootargs

[zoucao-ipc]

any suggestions？

On 2018/4/10 上午10:59, zou...@linux.alibaba.com wrote:

From: zoucao 

Normally every BIOS reserved memory is used for some features, we can't
use them, but in some conditions,  users can ensure some BIOS memories
are not used and reserved memory is well to free, they have not a good
way to free these memories, here add a new chareater "-" in memmap to
free reserved memory.

Signed-off-by: zou cao 
---
  7u/Documentation/kernel-parameters.txt | 6 ++
  7u/arch/x86/kernel/e820.c  | 3 +++
  2 files changed, 9 insertions(+)

diff --git a/7u/Documentation/kernel-parameters.txt 
b/7u/Documentation/kernel-parameters.txt
index 9a1abb99a..dbea75e12 100644
--- a/7u/Documentation/kernel-parameters.txt
+++ b/7u/Documentation/kernel-parameters.txt
@@ -1677,6 +1677,12 @@ bytes respectively. Such letter suffixes can also be 
entirely omitted.
 or
 memmap=0x1$0x1869
  
+	memmap=nn[KMG]-ss[KMG]

+   Free E820 reserved memory, as specified by the user.
+   Region of reserved memory to be free, from ss to ss+nn.
+   Example: free reserved memory from 0x1869-0x186a
+   memmap=0x4101000-0x6aeff000
+
memory_corruption_check=0/1 [X86]
Some BIOSes seem to corrupt the first 64k of
memory when doing things like suspend/resume.
diff --git a/7u/arch/x86/kernel/e820.c b/7u/arch/x86/kernel/e820.c
index 174da5fc5..b8a042981 100644
--- a/7u/arch/x86/kernel/e820.c
+++ b/7u/arch/x86/kernel/e820.c
@@ -875,6 +875,9 @@ static int __init parse_memmap_one(char *p)
} else if (*p == '$') {
start_at = memparse(p+1, );
e820_add_region(start_at, mem_size, E820_RESERVED);
+   } else if (*p == '-') {
+   start_at = memparse(p+1, );
+   e820_remove_range(start_at, mem_size, E820_RESERVED, E820_RAM);
} else
e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
  

Re: [PATCH] free e820 reserved memory in bootargs memmap

[zoucao-ipc]

I found commit characters errors, please ignore this path, V2 will be 
sent soon


On 2018/4/8 下午2:41, zou...@linux.alibaba.com wrote:

add a new chareater "-" in bootargs memmap, you can use this chareater to free
e820 reserved memory, for example:

reserved iomem:
cat /proc/iomem:
..
0010-6aefefff : System RAM
  0100-0165537a : Kernel code
  0165537b-01a8873f : Kernel data
  01c31000-01f4efff : Kernel bss
  2800-320f : Crash kernel
6aeff000-6eff : reserved   --> it is e820 reserved memory
6f00-78240fff : System RAM
..


add bootargs memmap=0x4101000-0x6aeff000, to free memory region: 
6aeff000-6eff
then 6aeff000-6eff will be merged into 0010-78240fff.

new iomem:
cat /proc/iomem:
..
0010-78240fff : System RAM
  0100-0165537a : Kernel code
  0165537b-01a8873f : Kernel data
  01c31000-01f4efff : Kernel bss
..

Re: [PATCH] x86/boot/e820: add new chareater "-" to free BIOS memory in memmap bootargs

[zoucao-ipc]

any suggestions？

On 2018/4/10 上午10:59, zou...@linux.alibaba.com wrote:

From: zoucao 

Normally every BIOS reserved memory is used for some features, we can't
use them, but in some conditions,  users can ensure some BIOS memories
are not used and reserved memory is well to free, they have not a good
way to free these memories, here add a new chareater "-" in memmap to
free reserved memory.

Signed-off-by: zou cao 
---
  7u/Documentation/kernel-parameters.txt | 6 ++
  7u/arch/x86/kernel/e820.c  | 3 +++
  2 files changed, 9 insertions(+)

diff --git a/7u/Documentation/kernel-parameters.txt 
b/7u/Documentation/kernel-parameters.txt
index 9a1abb99a..dbea75e12 100644
--- a/7u/Documentation/kernel-parameters.txt
+++ b/7u/Documentation/kernel-parameters.txt
@@ -1677,6 +1677,12 @@ bytes respectively. Such letter suffixes can also be 
entirely omitted.
 or
 memmap=0x1$0x1869
  
+	memmap=nn[KMG]-ss[KMG]

+   Free E820 reserved memory, as specified by the user.
+   Region of reserved memory to be free, from ss to ss+nn.
+   Example: free reserved memory from 0x1869-0x186a
+   memmap=0x4101000-0x6aeff000
+
memory_corruption_check=0/1 [X86]
Some BIOSes seem to corrupt the first 64k of
memory when doing things like suspend/resume.
diff --git a/7u/arch/x86/kernel/e820.c b/7u/arch/x86/kernel/e820.c
index 174da5fc5..b8a042981 100644
--- a/7u/arch/x86/kernel/e820.c
+++ b/7u/arch/x86/kernel/e820.c
@@ -875,6 +875,9 @@ static int __init parse_memmap_one(char *p)
} else if (*p == '$') {
start_at = memparse(p+1, );
e820_add_region(start_at, mem_size, E820_RESERVED);
+   } else if (*p == '-') {
+   start_at = memparse(p+1, );
+   e820_remove_range(start_at, mem_size, E820_RESERVED, E820_RAM);
} else
e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
  

Re: [PATCH] x86/boot/e820: add new chareater "-" to free BIOS memory in memmap bootargs

[zoucao-ipc]

ping?

On 2018/4/10 上午10:59, zou...@linux.alibaba.com wrote:

From: zoucao 

Normally every BIOS reserved memory is used for some features, we can't
use them, but in some conditions,  users can ensure some BIOS memories
are not used and reserved memory is well to free, they have not a good
way to free these memories, here add a new chareater "-" in memmap to
free reserved memory.

Signed-off-by: zou cao 
---
  7u/Documentation/kernel-parameters.txt | 6 ++
  7u/arch/x86/kernel/e820.c  | 3 +++
  2 files changed, 9 insertions(+)

diff --git a/7u/Documentation/kernel-parameters.txt 
b/7u/Documentation/kernel-parameters.txt
index 9a1abb99a..dbea75e12 100644
--- a/7u/Documentation/kernel-parameters.txt
+++ b/7u/Documentation/kernel-parameters.txt
@@ -1677,6 +1677,12 @@ bytes respectively. Such letter suffixes can also be 
entirely omitted.
 or
 memmap=0x1$0x1869
  
+	memmap=nn[KMG]-ss[KMG]

+   Free E820 reserved memory, as specified by the user.
+   Region of reserved memory to be free, from ss to ss+nn.
+   Example: free reserved memory from 0x1869-0x186a
+   memmap=0x4101000-0x6aeff000
+
memory_corruption_check=0/1 [X86]
Some BIOSes seem to corrupt the first 64k of
memory when doing things like suspend/resume.
diff --git a/7u/arch/x86/kernel/e820.c b/7u/arch/x86/kernel/e820.c
index 174da5fc5..b8a042981 100644
--- a/7u/arch/x86/kernel/e820.c
+++ b/7u/arch/x86/kernel/e820.c
@@ -875,6 +875,9 @@ static int __init parse_memmap_one(char *p)
} else if (*p == '$') {
start_at = memparse(p+1, );
e820_add_region(start_at, mem_size, E820_RESERVED);
+   } else if (*p == '-') {
+   start_at = memparse(p+1, );
+   e820_remove_range(start_at, mem_size, E820_RESERVED, E820_RAM);
} else
e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
  

Re: [PATCH] x86/boot/e820: add new chareater "-" to free BIOS memory in memmap bootargs

[zoucao-ipc]

Hi thomas:

Sorry, i don't receive yesterday email, i think the ping email is lost,
so bad me.
Anyway，have you some suggestions for this little patch? i really need 
your help.


Regards,
czou

On 2018/4/17 下午6:22, Thomas Gleixner wrote:

On Tue, 17 Apr 2018, zoucao-ipc wrote:


ping?

You already pinged yesterday. Are you going to switch to hourly pings
tomorrow?

Re: [PATCH] x86/boot/e820: add new chareater "-" to free BIOS memory in memmap bootargs

[zoucao-ipc]

On 2018/4/17 下午9:47, Thomas Gleixner wrote:

On Tue, 10 Apr 2018, zou...@linux.alibaba.com wrote:

From: zoucao 

Interesting from ... Please use your real mail address for this.

miss this, i will do it.

Normally every BIOS reserved memory is used for some features, we can't
use them, but in some conditions,  users can ensure some BIOS memories
are not used and reserved memory is well to free, they have not a good
way to free these memories, here add a new chareater "-" in memmap to
free reserved memory.

I'm not really convinced about this. How should anyone without detailed
BIOS knowledge know that this is really reusable?

The person who knows must have access to the BIOS developer, so why can't
the BIOS be fixed instead?

Thanks,

tglx


Signed-off-by: zou cao 
---
  7u/Documentation/kernel-parameters.txt | 6 ++
  7u/arch/x86/kernel/e820.c  | 3 +++
  2 files changed, 9 insertions(+)

diff --git a/7u/Documentation/kernel-parameters.txt 
b/7u/Documentation/kernel-parameters.txt
index 9a1abb99a..dbea75e12 100644
--- a/7u/Documentation/kernel-parameters.txt
+++ b/7u/Documentation/kernel-parameters.txt
@@ -1677,6 +1677,12 @@ bytes respectively. Such letter suffixes can also be 
entirely omitted.
 or
 memmap=0x1$0x1869
  
+	memmap=nn[KMG]-ss[KMG]

+   Free E820 reserved memory, as specified by the user.
+   Region of reserved memory to be free, from ss to ss+nn.
+   Example: free reserved memory from 0x1869-0x186a
+   memmap=0x4101000-0x6aeff000
+
memory_corruption_check=0/1 [X86]
Some BIOSes seem to corrupt the first 64k of
memory when doing things like suspend/resume.
diff --git a/7u/arch/x86/kernel/e820.c b/7u/arch/x86/kernel/e820.c
index 174da5fc5..b8a042981 100644
--- a/7u/arch/x86/kernel/e820.c
+++ b/7u/arch/x86/kernel/e820.c
@@ -875,6 +875,9 @@ static int __init parse_memmap_one(char *p)
} else if (*p == '$') {
start_at = memparse(p+1, );
e820_add_region(start_at, mem_size, E820_RESERVED);
+   } else if (*p == '-') {
+   start_at = memparse(p+1, );
+   e820_remove_range(start_at, mem_size, E820_RESERVED, E820_RAM);
} else
e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
  
--

2.14.1.40.g8e62ba1