Commit 59d58189f3d9 ("crash: fix crash memory reserve exceed system
memory bug") fails crashkernel parsing if the crash size is found to be
higher than system RAM, which makes the memory_limit adjustment code
ineffective due to an early exit from reserve_crashkernel().

Regardless lets not violated the user-specified memory limit by
adjusting it. Remove this adjustment to ensure all reservations stay
within the limit. Commit f94f5ac07983 ("powerpc/fadump: Don't update
the user-specified memory limit") did the same for fadump.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Baoquan he <bhe@redhat.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
CC: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: kexec@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
---
 arch/powerpc/kexec/core.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/arch/powerpc/kexec/core.c b/arch/powerpc/kexec/core.c
index b8333a49ea5d..4945b33322ae 100644
--- a/arch/powerpc/kexec/core.c
+++ b/arch/powerpc/kexec/core.c
@@ -150,14 +150,6 @@ void __init reserve_crashkernel(void)
 		return;
 	}
 
-	/* Crash kernel trumps memory limit */
-	if (memory_limit && memory_limit <= crashk_res.end) {
-		memory_limit = crashk_res.end + 1;
-		total_mem_sz = memory_limit;
-		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
-		       memory_limit);
-	}
-
 	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
 			"for crashkernel (System RAM: %ldMB)\n",
 			(unsigned long)(crash_size >> 20),
-- 
2.47.1

On 21/01/25 5:24 pm, Sourabh Jain wrote:
> Commit 59d58189f3d9 ("crash: fix crash memory reserve exceed system
> memory bug") fails crashkernel parsing if the crash size is found to be
> higher than system RAM, which makes the memory_limit adjustment code
> ineffective due to an early exit from reserve_crashkernel().
> 
> Regardless lets not violated the user-specified memory limit by

s/violated/violate/

> adjusting it. Remove this adjustment to ensure all reservations stay
> within the limit. Commit f94f5ac07983 ("powerpc/fadump: Don't update
> the user-specified memory limit") did the same for fadump.
> 

Acked-by: Hari Bathini <hbathini@linux.ibm.com>

> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Baoquan he <bhe@redhat.com>
> Cc: Hari Bathini <hbathini@linux.ibm.com>
> CC: Madhavan Srinivasan <maddy@linux.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: kexec@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
> Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
> ---
>   arch/powerpc/kexec/core.c | 8 --------
>   1 file changed, 8 deletions(-)
> 
> diff --git a/arch/powerpc/kexec/core.c b/arch/powerpc/kexec/core.c
> index b8333a49ea5d..4945b33322ae 100644
> --- a/arch/powerpc/kexec/core.c
> +++ b/arch/powerpc/kexec/core.c
> @@ -150,14 +150,6 @@ void __init reserve_crashkernel(void)
>   		return;
>   	}
>   
> -	/* Crash kernel trumps memory limit */
> -	if (memory_limit && memory_limit <= crashk_res.end) {
> -		memory_limit = crashk_res.end + 1;
> -		total_mem_sz = memory_limit;
> -		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
> -		       memory_limit);
> -	}
> -
>   	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
>   			"for crashkernel (System RAM: %ldMB)\n",
>   			(unsigned long)(crash_size >> 20),

Hello Hari,


On 23/01/25 16:00, Hari Bathini wrote:
>
>
> On 21/01/25 5:24 pm, Sourabh Jain wrote:
>> Commit 59d58189f3d9 ("crash: fix crash memory reserve exceed system
>> memory bug") fails crashkernel parsing if the crash size is found to be
>> higher than system RAM, which makes the memory_limit adjustment code
>> ineffective due to an early exit from reserve_crashkernel().
>>
>> Regardless lets not violated the user-specified memory limit by
>
> s/violated/violate/

Noted. It will be fixed in next version.

>
>> adjusting it. Remove this adjustment to ensure all reservations stay
>> within the limit. Commit f94f5ac07983 ("powerpc/fadump: Don't update
>> the user-specified memory limit") did the same for fadump.
>>
>
> Acked-by: Hari Bathini <hbathini@linux.ibm.com>

Thanks for the Ack!

- Sourabh Jain


>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Cc: Baoquan he <bhe@redhat.com>
>> Cc: Hari Bathini <hbathini@linux.ibm.com>
>> CC: Madhavan Srinivasan <maddy@linux.ibm.com>
>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>> Cc: kexec@lists.infradead.org
>> Cc: linux-kernel@vger.kernel.org
>> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
>> Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
>> ---
>>   arch/powerpc/kexec/core.c | 8 --------
>>   1 file changed, 8 deletions(-)
>>
>> diff --git a/arch/powerpc/kexec/core.c b/arch/powerpc/kexec/core.c
>> index b8333a49ea5d..4945b33322ae 100644
>> --- a/arch/powerpc/kexec/core.c
>> +++ b/arch/powerpc/kexec/core.c
>> @@ -150,14 +150,6 @@ void __init reserve_crashkernel(void)
>>           return;
>>       }
>>   -    /* Crash kernel trumps memory limit */
>> -    if (memory_limit && memory_limit <= crashk_res.end) {
>> -        memory_limit = crashk_res.end + 1;
>> -        total_mem_sz = memory_limit;
>> -        printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
>> -               memory_limit);
>> -    }
>> -
>>       printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
>>               "for crashkernel (System RAM: %ldMB)\n",
>>               (unsigned long)(crash_size >> 20),
>