[PATCH v4 1/1] kernel/crash_core: Add crashkernel=auto for vmcore creation

[PATCH v4 1/1] kernel/crash_core: Add crashkernel=auto for vmcore creation

[Saeed Mirzamohammadi]

This adds crashkernel=auto feature to configure reserved memory for
vmcore creation. CONFIG_CRASH_AUTO_STR is defined to be set for
different kernel distributions and different archs based on their
needs.

Signed-off-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
Signed-off-by: John Donnelly <john.p.donnelly@oracle.com>
Tested-by: John Donnelly <john.p.donnelly@oracle.com>
---
 Documentation/admin-guide/kdump/kdump.rst     |  3 ++-
 .../admin-guide/kernel-parameters.txt         |  6 ++++++
 arch/Kconfig                                  | 20 +++++++++++++++++++
 kernel/crash_core.c                           |  7 +++++++
 4 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst
index 75a9dd98e76e..ae030111e22a 100644
--- a/Documentation/admin-guide/kdump/kdump.rst
+++ b/Documentation/admin-guide/kdump/kdump.rst
@@ -285,7 +285,8 @@ This would mean:
     2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
     3) if the RAM size is larger than 2G, then reserve 128M
 
-
+Or you can use crashkernel=auto to choose the crash kernel memory size
+based on the recommended configuration set for each arch.
 
 Boot into System Kernel
 =======================
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 9e3cdb271d06..a5deda5c85fe 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -747,6 +747,12 @@
 			a memory unit (amount[KMG]). See also
 			Documentation/admin-guide/kdump/kdump.rst for an example.
 
+	crashkernel=auto
+			[KNL] This parameter will set the reserved memory for
+			the crash kernel based on the value of the CRASH_AUTO_STR
+			that is the best effort estimation for each arch. See also
+			arch/Kconfig for further details.
+
 	crashkernel=size[KMG],high
 			[KNL, X86-64] range could be above 4G. Allow kernel
 			to allocate physical memory region from top, so could
diff --git a/arch/Kconfig b/arch/Kconfig
index 24862d15f3a3..23d047548772 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -14,6 +14,26 @@ menu "General architecture-dependent options"
 config CRASH_CORE
 	bool
 
+config CRASH_AUTO_STR
+	string "Memory reserved for crash kernel"
+	depends on CRASH_CORE
+	default "1G-64G:128M,64G-1T:256M,1T-:512M"
+	help
+	  This configures the reserved memory dependent
+	  on the value of System RAM. The syntax is:
+	  crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
+	              range=start-[end]
+
+	  For example:
+	      crashkernel=512M-2G:64M,2G-:128M
+
+	  This would mean:
+
+	      1) if the RAM is smaller than 512M, then don't reserve anything
+	         (this is the "rescue" case)
+	      2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
+	      3) if the RAM size is larger than 2G, then reserve 128M
+
 config KEXEC_CORE
 	select CRASH_CORE
 	bool
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 825284baaf46..90f9e4bb6704 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -7,6 +7,7 @@
 #include <linux/crash_core.h>
 #include <linux/utsname.h>
 #include <linux/vmalloc.h>
+#include <linux/kexec.h>
 
 #include <asm/page.h>
 #include <asm/sections.h>
@@ -250,6 +251,12 @@ static int __init __parse_crashkernel(char *cmdline,
 	if (suffix)
 		return parse_crashkernel_suffix(ck_cmdline, crash_size,
 				suffix);
+#ifdef CONFIG_CRASH_AUTO_STR
+	if (strncmp(ck_cmdline, "auto", 4) == 0) {
+		ck_cmdline = CONFIG_CRASH_AUTO_STR;
+		pr_info("Using crashkernel=auto, the size chosen is a best effort estimation.\n");
+	}
+#endif
 	/*
 	 * if the commandline contains a ':', then that's the extended
 	 * syntax -- if not, it must be the classic syntax
-- 
2.27.0

Re: [PATCH v4 1/1] kernel/crash_core: Add crashkernel=auto for vmcore creation

[Baoquan He]

On 02/23/21 at 09:41am, Saeed Mirzamohammadi wrote:
> This adds crashkernel=auto feature to configure reserved memory for
> vmcore creation. CONFIG_CRASH_AUTO_STR is defined to be set for
> different kernel distributions and different archs based on their
> needs.
> 
> Signed-off-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
> Signed-off-by: John Donnelly <john.p.donnelly@oracle.com>
> Tested-by: John Donnelly <john.p.donnelly@oracle.com>

Looks good, thx.

Acked-by: Baoquan He <bhe@redhat.com>

By the way, please provide changelog in the future. That can help people
know better what's happened during patch reviewing and evolution.

Thanks
Baoquan

> ---
>  Documentation/admin-guide/kdump/kdump.rst     |  3 ++-
>  .../admin-guide/kernel-parameters.txt         |  6 ++++++
>  arch/Kconfig                                  | 20 +++++++++++++++++++
>  kernel/crash_core.c                           |  7 +++++++
>  4 files changed, 35 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst
> index 75a9dd98e76e..ae030111e22a 100644
> --- a/Documentation/admin-guide/kdump/kdump.rst
> +++ b/Documentation/admin-guide/kdump/kdump.rst
> @@ -285,7 +285,8 @@ This would mean:
>      2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
>      3) if the RAM size is larger than 2G, then reserve 128M
>  
> -
> +Or you can use crashkernel=auto to choose the crash kernel memory size
> +based on the recommended configuration set for each arch.
>  
>  Boot into System Kernel
>  =======================
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 9e3cdb271d06..a5deda5c85fe 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -747,6 +747,12 @@
>  			a memory unit (amount[KMG]). See also
>  			Documentation/admin-guide/kdump/kdump.rst for an example.
>  
> +	crashkernel=auto
> +			[KNL] This parameter will set the reserved memory for
> +			the crash kernel based on the value of the CRASH_AUTO_STR
> +			that is the best effort estimation for each arch. See also
> +			arch/Kconfig for further details.
> +
>  	crashkernel=size[KMG],high
>  			[KNL, X86-64] range could be above 4G. Allow kernel
>  			to allocate physical memory region from top, so could
> diff --git a/arch/Kconfig b/arch/Kconfig
> index 24862d15f3a3..23d047548772 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -14,6 +14,26 @@ menu "General architecture-dependent options"
>  config CRASH_CORE
>  	bool
>  
> +config CRASH_AUTO_STR
> +	string "Memory reserved for crash kernel"
> +	depends on CRASH_CORE
> +	default "1G-64G:128M,64G-1T:256M,1T-:512M"
> +	help
> +	  This configures the reserved memory dependent
> +	  on the value of System RAM. The syntax is:
> +	  crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
> +	              range=start-[end]
> +
> +	  For example:
> +	      crashkernel=512M-2G:64M,2G-:128M
> +
> +	  This would mean:
> +
> +	      1) if the RAM is smaller than 512M, then don't reserve anything
> +	         (this is the "rescue" case)
> +	      2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
> +	      3) if the RAM size is larger than 2G, then reserve 128M
> +
>  config KEXEC_CORE
>  	select CRASH_CORE
>  	bool
> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> index 825284baaf46..90f9e4bb6704 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -7,6 +7,7 @@
>  #include <linux/crash_core.h>
>  #include <linux/utsname.h>
>  #include <linux/vmalloc.h>
> +#include <linux/kexec.h>
>  
>  #include <asm/page.h>
>  #include <asm/sections.h>
> @@ -250,6 +251,12 @@ static int __init __parse_crashkernel(char *cmdline,
>  	if (suffix)
>  		return parse_crashkernel_suffix(ck_cmdline, crash_size,
>  				suffix);
> +#ifdef CONFIG_CRASH_AUTO_STR
> +	if (strncmp(ck_cmdline, "auto", 4) == 0) {
> +		ck_cmdline = CONFIG_CRASH_AUTO_STR;
> +		pr_info("Using crashkernel=auto, the size chosen is a best effort estimation.\n");
> +	}
> +#endif
>  	/*
>  	 * if the commandline contains a ':', then that's the extended
>  	 * syntax -- if not, it must be the classic syntax
> -- 
> 2.27.0
> 

Re: [PATCH v4 1/1] kernel/crash_core: Add crashkernel=auto for vmcore creation

[Kairui Song]

On Wed, Feb 24, 2021 at 1:45 AM Saeed Mirzamohammadi
<saeed.mirzamohammadi@oracle.com> wrote:
>
> This adds crashkernel=auto feature to configure reserved memory for
> vmcore creation. CONFIG_CRASH_AUTO_STR is defined to be set for
> different kernel distributions and different archs based on their
> needs.
>
> Signed-off-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
> Signed-off-by: John Donnelly <john.p.donnelly@oracle.com>
> Tested-by: John Donnelly <john.p.donnelly@oracle.com>
> ---
>  Documentation/admin-guide/kdump/kdump.rst     |  3 ++-
>  .../admin-guide/kernel-parameters.txt         |  6 ++++++
>  arch/Kconfig                                  | 20 +++++++++++++++++++
>  kernel/crash_core.c                           |  7 +++++++
>  4 files changed, 35 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst
> index 75a9dd98e76e..ae030111e22a 100644
> --- a/Documentation/admin-guide/kdump/kdump.rst
> +++ b/Documentation/admin-guide/kdump/kdump.rst
> @@ -285,7 +285,8 @@ This would mean:
>      2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
>      3) if the RAM size is larger than 2G, then reserve 128M
>
> -
> +Or you can use crashkernel=auto to choose the crash kernel memory size
> +based on the recommended configuration set for each arch.
>
>  Boot into System Kernel
>  =======================
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 9e3cdb271d06..a5deda5c85fe 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -747,6 +747,12 @@
>                         a memory unit (amount[KMG]). See also
>                         Documentation/admin-guide/kdump/kdump.rst for an example.
>
> +       crashkernel=auto
> +                       [KNL] This parameter will set the reserved memory for
> +                       the crash kernel based on the value of the CRASH_AUTO_STR
> +                       that is the best effort estimation for each arch. See also
> +                       arch/Kconfig for further details.
> +
>         crashkernel=size[KMG],high
>                         [KNL, X86-64] range could be above 4G. Allow kernel
>                         to allocate physical memory region from top, so could
> diff --git a/arch/Kconfig b/arch/Kconfig
> index 24862d15f3a3..23d047548772 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -14,6 +14,26 @@ menu "General architecture-dependent options"
>  config CRASH_CORE
>         bool
>
> +config CRASH_AUTO_STR
> +       string "Memory reserved for crash kernel"
> +       depends on CRASH_CORE
> +       default "1G-64G:128M,64G-1T:256M,1T-:512M"
> +       help
> +         This configures the reserved memory dependent
> +         on the value of System RAM. The syntax is:
> +         crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
> +                     range=start-[end]
> +
> +         For example:
> +             crashkernel=512M-2G:64M,2G-:128M
> +
> +         This would mean:
> +
> +             1) if the RAM is smaller than 512M, then don't reserve anything
> +                (this is the "rescue" case)
> +             2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
> +             3) if the RAM size is larger than 2G, then reserve 128M
> +
>  config KEXEC_CORE
>         select CRASH_CORE
>         bool
> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> index 825284baaf46..90f9e4bb6704 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -7,6 +7,7 @@
>  #include <linux/crash_core.h>
>  #include <linux/utsname.h>
>  #include <linux/vmalloc.h>
> +#include <linux/kexec.h>
>
>  #include <asm/page.h>
>  #include <asm/sections.h>
> @@ -250,6 +251,12 @@ static int __init __parse_crashkernel(char *cmdline,
>         if (suffix)
>                 return parse_crashkernel_suffix(ck_cmdline, crash_size,
>                                 suffix);
> +#ifdef CONFIG_CRASH_AUTO_STR
> +       if (strncmp(ck_cmdline, "auto", 4) == 0) {
> +               ck_cmdline = CONFIG_CRASH_AUTO_STR;
> +               pr_info("Using crashkernel=auto, the size chosen is a best effort estimation.\n");
> +       }
> +#endif
>         /*
>          * if the commandline contains a ':', then that's the extended
>          * syntax -- if not, it must be the classic syntax
> --
> 2.27.0
>
>
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
>

Thanks for help pushing the crashkernel=auto to upstream
This patch works well.

Tested-by: Kairui Song <kasong@redhat.com>


--
Best Regards,
Kairui Song

Re: [PATCH v4 1/1] kernel/crash_core: Add crashkernel=auto for vmcore creation

[Dave Young]

On 02/23/21 at 09:41am, Saeed Mirzamohammadi wrote:
> This adds crashkernel=auto feature to configure reserved memory for
> vmcore creation. CONFIG_CRASH_AUTO_STR is defined to be set for
> different kernel distributions and different archs based on their
> needs.
> 
> Signed-off-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
> Signed-off-by: John Donnelly <john.p.donnelly@oracle.com>
> Tested-by: John Donnelly <john.p.donnelly@oracle.com>
> ---
>  Documentation/admin-guide/kdump/kdump.rst     |  3 ++-
>  .../admin-guide/kernel-parameters.txt         |  6 ++++++
>  arch/Kconfig                                  | 20 +++++++++++++++++++
>  kernel/crash_core.c                           |  7 +++++++
>  4 files changed, 35 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst
> index 75a9dd98e76e..ae030111e22a 100644
> --- a/Documentation/admin-guide/kdump/kdump.rst
> +++ b/Documentation/admin-guide/kdump/kdump.rst
> @@ -285,7 +285,8 @@ This would mean:
>      2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
>      3) if the RAM size is larger than 2G, then reserve 128M
>  
> -
> +Or you can use crashkernel=auto to choose the crash kernel memory size
> +based on the recommended configuration set for each arch.
>  
>  Boot into System Kernel
>  =======================
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 9e3cdb271d06..a5deda5c85fe 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -747,6 +747,12 @@
>  			a memory unit (amount[KMG]). See also
>  			Documentation/admin-guide/kdump/kdump.rst for an example.
>  
> +	crashkernel=auto
> +			[KNL] This parameter will set the reserved memory for
> +			the crash kernel based on the value of the CRASH_AUTO_STR
> +			that is the best effort estimation for each arch. See also
> +			arch/Kconfig for further details.
> +
>  	crashkernel=size[KMG],high
>  			[KNL, X86-64] range could be above 4G. Allow kernel
>  			to allocate physical memory region from top, so could
> diff --git a/arch/Kconfig b/arch/Kconfig
> index 24862d15f3a3..23d047548772 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -14,6 +14,26 @@ menu "General architecture-dependent options"
>  config CRASH_CORE
>  	bool
>  
> +config CRASH_AUTO_STR
> +	string "Memory reserved for crash kernel"
> +	depends on CRASH_CORE
> +	default "1G-64G:128M,64G-1T:256M,1T-:512M"
> +	help
> +	  This configures the reserved memory dependent
> +	  on the value of System RAM. The syntax is:
> +	  crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
> +	              range=start-[end]
> +
> +	  For example:
> +	      crashkernel=512M-2G:64M,2G-:128M
> +
> +	  This would mean:
> +
> +	      1) if the RAM is smaller than 512M, then don't reserve anything
> +	         (this is the "rescue" case)
> +	      2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
> +	      3) if the RAM size is larger than 2G, then reserve 128M
> +
>  config KEXEC_CORE
>  	select CRASH_CORE
>  	bool
> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> index 825284baaf46..90f9e4bb6704 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -7,6 +7,7 @@
>  #include <linux/crash_core.h>
>  #include <linux/utsname.h>
>  #include <linux/vmalloc.h>
> +#include <linux/kexec.h>
>  
>  #include <asm/page.h>
>  #include <asm/sections.h>
> @@ -250,6 +251,12 @@ static int __init __parse_crashkernel(char *cmdline,
>  	if (suffix)
>  		return parse_crashkernel_suffix(ck_cmdline, crash_size,
>  				suffix);
> +#ifdef CONFIG_CRASH_AUTO_STR
> +	if (strncmp(ck_cmdline, "auto", 4) == 0) {
> +		ck_cmdline = CONFIG_CRASH_AUTO_STR;
> +		pr_info("Using crashkernel=auto, the size chosen is a best effort estimation.\n");
> +	}
> +#endif
>  	/*
>  	 * if the commandline contains a ':', then that's the extended
>  	 * syntax -- if not, it must be the classic syntax
> -- 
> 2.27.0
> 


Acked-by: Dave Young <dyoung@redhat.com>

Thanks
Dave

Re: [PATCH v4 1/1] kernel/crash_core: Add crashkernel=auto for vmcore creation

[john.p.donnelly]

On 2/25/21 6:38 PM, Dave Young wrote:
> On 02/23/21 at 09:41am, Saeed Mirzamohammadi wrote:
>> This adds crashkernel=auto feature to configure reserved memory for
>> vmcore creation. CONFIG_CRASH_AUTO_STR is defined to be set for
>> different kernel distributions and different archs based on their
>> needs.
>>
>> Signed-off-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
>> Signed-off-by: John Donnelly <john.p.donnelly@oracle.com>
>> Tested-by: John Donnelly <john.p.donnelly@oracle.com>
>> ---
>>   Documentation/admin-guide/kdump/kdump.rst     |  3 ++-
>>   .../admin-guide/kernel-parameters.txt         |  6 ++++++
>>   arch/Kconfig                                  | 20 +++++++++++++++++++
>>   kernel/crash_core.c                           |  7 +++++++
>>   4 files changed, 35 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst
>> index 75a9dd98e76e..ae030111e22a 100644
>> --- a/Documentation/admin-guide/kdump/kdump.rst
>> +++ b/Documentation/admin-guide/kdump/kdump.rst
>> @@ -285,7 +285,8 @@ This would mean:
>>       2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
>>       3) if the RAM size is larger than 2G, then reserve 128M
>>   
>> -
>> +Or you can use crashkernel=auto to choose the crash kernel memory size
>> +based on the recommended configuration set for each arch.
>>   
>>   Boot into System Kernel
>>   =======================
>> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
>> index 9e3cdb271d06..a5deda5c85fe 100644
>> --- a/Documentation/admin-guide/kernel-parameters.txt
>> +++ b/Documentation/admin-guide/kernel-parameters.txt
>> @@ -747,6 +747,12 @@
>>   			a memory unit (amount[KMG]). See also
>>   			Documentation/admin-guide/kdump/kdump.rst for an example.
>>   
>> +	crashkernel=auto
>> +			[KNL] This parameter will set the reserved memory for
>> +			the crash kernel based on the value of the CRASH_AUTO_STR
>> +			that is the best effort estimation for each arch. See also
>> +			arch/Kconfig for further details.
>> +
>>   	crashkernel=size[KMG],high
>>   			[KNL, X86-64] range could be above 4G. Allow kernel
>>   			to allocate physical memory region from top, so could
>> diff --git a/arch/Kconfig b/arch/Kconfig
>> index 24862d15f3a3..23d047548772 100644
>> --- a/arch/Kconfig
>> +++ b/arch/Kconfig
>> @@ -14,6 +14,26 @@ menu "General architecture-dependent options"
>>   config CRASH_CORE
>>   	bool
>>   
>> +config CRASH_AUTO_STR
>> +	string "Memory reserved for crash kernel"
>> +	depends on CRASH_CORE
>> +	default "1G-64G:128M,64G-1T:256M,1T-:512M"
>> +	help
>> +	  This configures the reserved memory dependent
>> +	  on the value of System RAM. The syntax is:
>> +	  crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
>> +	              range=start-[end]
>> +
>> +	  For example:
>> +	      crashkernel=512M-2G:64M,2G-:128M
>> +
>> +	  This would mean:
>> +
>> +	      1) if the RAM is smaller than 512M, then don't reserve anything
>> +	         (this is the "rescue" case)
>> +	      2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
>> +	      3) if the RAM size is larger than 2G, then reserve 128M
>> +
>>   config KEXEC_CORE
>>   	select CRASH_CORE
>>   	bool
>> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
>> index 825284baaf46..90f9e4bb6704 100644
>> --- a/kernel/crash_core.c
>> +++ b/kernel/crash_core.c
>> @@ -7,6 +7,7 @@
>>   #include <linux/crash_core.h>
>>   #include <linux/utsname.h>
>>   #include <linux/vmalloc.h>
>> +#include <linux/kexec.h>
>>   
>>   #include <asm/page.h>
>>   #include <asm/sections.h>
>> @@ -250,6 +251,12 @@ static int __init __parse_crashkernel(char *cmdline,
>>   	if (suffix)
>>   		return parse_crashkernel_suffix(ck_cmdline, crash_size,
>>   				suffix);
>> +#ifdef CONFIG_CRASH_AUTO_STR
>> +	if (strncmp(ck_cmdline, "auto", 4) == 0) {
>> +		ck_cmdline = CONFIG_CRASH_AUTO_STR;
>> +		pr_info("Using crashkernel=auto, the size chosen is a best effort estimation.\n");
>> +	}
>> +#endif
>>   	/*
>>   	 * if the commandline contains a ':', then that's the extended
>>   	 * syntax -- if not, it must be the classic syntax
>> -- 
>> 2.27.0
>>
> 
> 
> Acked-by: Dave Young <dyoung@redhat.com>
> 
> Thanks
> Dave
> 
Hi,

   Thank you.

   When can  we expect this to be applied in a future build ?