diff mbox series

[RESEND,v1,3/5] powerpc/kdump: preserve user-specified memory limit

Message ID 20250108101458.406806-4-sourabhjain@linux.ibm.com (mailing list archive)
State Superseded
Headers show
Series powerpc/crash: use generic crashkernel reservation | expand

Commit Message

Sourabh Jain Jan. 8, 2025, 10:14 a.m. UTC
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
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
---
 arch/powerpc/kexec/core.c | 8 --------
 1 file changed, 8 deletions(-)

Comments

Mahesh Salgaonkar Jan. 8, 2025, 5:06 p.m. UTC | #1
On 2025-01-08 15:44:56 Wed, 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
> 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.

Agreed.

Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>

Thanks,
-Mahesh.
Sourabh Jain Jan. 9, 2025, 3:24 a.m. UTC | #2
Hello Mahesh,


On 08/01/25 22:36, Mahesh J Salgaonkar wrote:
> On 2025-01-08 15:44:56 Wed, 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
>> 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.
> Agreed.
>
> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>

Thanks for the review.

- Sourabh Jain
diff mbox series

Patch

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),