The patch titled Subject: mm/memory_hotplug: fix memmap_on_memory sysfs value retrieval has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-memory_hotplug-fix-memmap_on_memory-sysfs-value-retrieval.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------ From: Sumanth Korikkar sumanthk@linux.ibm.com Subject: mm/memory_hotplug: fix memmap_on_memory sysfs value retrieval Date: Wed, 10 Jan 2024 15:01:27 +0100

set_memmap_mode() stores the kernel parameter memmap mode as an integer. However, the get_memmap_mode() function utilizes param_get_bool() to fetch the value as a boolean, leading to potential endianness issue. On Big-endian architectures, the memmap_on_memory is consistently displayed as 'N' regardless of its actual status.

To address this endianness problem, the solution involves obtaining the mode as an integer. This adjustment ensures the proper display of the memmap_on_memory parameter, presenting it as one of the following options: Force, Y, or N.

Link: https://lkml.kernel.org/r/20240110140127.241451-1-sumanthk@linux.ibm.com Fixes: 2d1f649c7c08 ("mm/memory_hotplug: support memmap_on_memory when memmap is not aligned to pageblocks") Signed-off-by: Sumanth Korikkar sumanthk@linux.ibm.com Suggested-by: Gerald Schaefer gerald.schaefer@linux.ibm.com Cc: Alexander Gordeev agordeev@linux.ibm.com Cc: Aneesh Kumar K.V aneesh.kumar@linux.ibm.com Cc: David Hildenbrand david@redhat.com Cc: Heiko Carstens hca@linux.ibm.com Cc: Michal Hocko mhocko@suse.com Cc: Oscar Salvador osalvador@suse.de Cc: Vasily Gorbik gor@linux.ibm.com Cc: stable@vger.kernel.org [6.6+] Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

mm/memory_hotplug.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/mm/memory_hotplug.c~mm-memory_hotplug-fix-memmap_on_memory-sysfs-value-retrieval +++ a/mm/memory_hotplug.c @@ -101,9 +101,11 @@ static int set_memmap_mode(const char *v

static int get_memmap_mode(char *buffer, const struct kernel_param *kp) { - if (*((int *)kp->arg) == MEMMAP_ON_MEMORY_FORCE) - return sprintf(buffer, "force\n"); - return param_get_bool(buffer, kp); + int mode = *((int *)kp->arg); + + if (mode == MEMMAP_ON_MEMORY_FORCE) + return sprintf(buffer, "force\n"); + return sprintf(buffer, "%c\n", mode ? 'Y' : 'N'); }

static const struct kernel_param_ops memmap_mode_ops = { _

Patches currently in -mm which might be from sumanthk@linux.ibm.com are

mm-memory_hotplug-fix-memmap_on_memory-sysfs-value-retrieval.patch mm-memory_hotplug-introduce-mem_prepare_online-mem_finish_offline-notifiers.patch s390-mm-allocate-vmemmap-pages-from-self-contained-memory-range.patch s390-sclp-remove-unhandled-memory-notifier-type.patch s390-mm-implement-mem_prepare_online-mem_finish_offline-notifiers.patch s390-enable-mhp_memmap_on_memory.patch