The patch titled Subject: powerpc/pseries/cmm: call balloon_devinfo_init() also without CONFIG_BALLOON_COMPACTION has been added to the -mm mm-new branch. Its filename is powerpc-pseries-cmm-call-balloon_devinfo_init-also-without-config_balloon_compaction.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-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------ From: David Hildenbrand david@redhat.com Subject: powerpc/pseries/cmm: call balloon_devinfo_init() also without CONFIG_BALLOON_COMPACTION Date: Tue, 21 Oct 2025 12:06:05 +0200

Patch series "powerpc/pseries/cmm: two smaller fixes".

Two smaller fixes identified while doing a bigger rework.

This patch (of 2):

We always have to initialize the balloon_dev_info, even when compaction is not configured in: otherwise the containing list and the lock are left uninitialized.

Likely not many such configs exist in practice, but let's CC stable to be sure.

This was found by code inspection.

Link: https://lkml.kernel.org/r/20251021100606.148294-1-david@redhat.com Link: https://lkml.kernel.org/r/20251021100606.148294-2-david@redhat.com Fixes: fe030c9b85e6 ("powerpc/pseries/cmm: Implement balloon compaction") Signed-off-by: David Hildenbrand david@redhat.com Cc: Christophe Leroy christophe.leroy@csgroup.eu Cc: Madhavan Srinivasan maddy@linux.ibm.com Cc: Michael Ellerman mpe@ellerman.id.au Cc: Nicholas Piggin npiggin@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

arch/powerpc/platforms/pseries/cmm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/powerpc/platforms/pseries/cmm.c~powerpc-pseries-cmm-call-balloon_devinfo_init-also-without-config_balloon_compaction +++ a/arch/powerpc/platforms/pseries/cmm.c @@ -550,7 +550,6 @@ static int cmm_migratepage(struct balloo

static void cmm_balloon_compaction_init(void) { - balloon_devinfo_init(&b_dev_info); b_dev_info.migratepage = cmm_migratepage; } #else /* CONFIG_BALLOON_COMPACTION */ @@ -572,6 +571,7 @@ static int cmm_init(void) if (!firmware_has_feature(FW_FEATURE_CMO) && !simulate) return -EOPNOTSUPP;

+ balloon_devinfo_init(&b_dev_info); cmm_balloon_compaction_init();

rc = register_oom_notifier(&cmm_oom_nb); _

Patches currently in -mm which might be from david@redhat.com are

powerpc-pseries-cmm-call-balloon_devinfo_init-also-without-config_balloon_compaction.patch powerpc-pseries-cmm-adjust-balloon_migrate-when-migrating-pages.patch