The patch titled
Subject: powerpc/crash: preserve user-specified memory limit
has been added to the -mm mm-nonmm-unstable branch. Its filename is
powerpc-crash-preserve-user-specified-memory-limit.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/powerpc-crash-preserve-user-specified-memory-limit.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Sourabh Jain <sourabhjain@xxxxxxxxxxxxx>
Subject: powerpc/crash: preserve user-specified memory limit
Date: Fri, 31 Jan 2025 17:08:28 +0530
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 violate 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.
Link: https://lkml.kernel.org/r/20250131113830.925179-6-sourabhjain@xxxxxxxxxxxxx
Signed-off-by: Sourabh Jain <sourabhjain@xxxxxxxxxxxxx>
Reviewed-by: Mahesh Salgaonkar <mahesh@xxxxxxxxxxxxx>
Acked-by: Hari Bathini <hbathini@xxxxxxxxxxxxx>
Cc: Baoquan he <bhe@xxxxxxxxxx>
Cc: Madhavan Srinivasan <maddy@xxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kexec/core.c | 8 --------
1 file changed, 8 deletions(-)
--- a/arch/powerpc/kexec/core.c~powerpc-crash-preserve-user-specified-memory-limit
+++ a/arch/powerpc/kexec/core.c
@@ -128,14 +128,6 @@ 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),
_
Patches currently in -mm which might be from sourabhjain@xxxxxxxxxxxxx are
kexec-initialize-elf-lowest-address-to-ulong_max.patch
crash-remove-an-unused-argument-from-reserve_crashkernel_generic.patch
crash-let-arch-decide-usable-memory-range-in-reserved-area.patch
powerpc-crash-use-generic-apis-to-locate-memory-hole-for-kdump.patch
powerpc-crash-preserve-user-specified-memory-limit.patch
powerpc-insert-system-ram-resource-to-prevent-crashkernel-conflict.patch
powerpc-crash-use-generic-crashkernel-reservation.patch
