[PATCH v1 1/2] powerpc/pseries/cmm: call balloon_devinfo_init() also without CONFIG_BALLOON_COMPACTION

[PATCH v1 1/2] powerpc/pseries/cmm: call balloon_devinfo_init() also without CONFIG_BALLOON_COMPACTION

[David Hildenbrand]

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.

Fixes: fe030c9b85e6 ("powerpc/pseries/cmm: Implement balloon compaction")
Cc: <stable@vger.kernel.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 arch/powerpc/platforms/pseries/cmm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c
index 0823fa2da1516..688f5fa1c7245 100644
--- a/arch/powerpc/platforms/pseries/cmm.c
+++ b/arch/powerpc/platforms/pseries/cmm.c
@@ -550,7 +550,6 @@ static int cmm_migratepage(struct balloon_dev_info *b_dev_info,
 
 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);
-- 
2.51.0

Re: [PATCH v1 1/2] powerpc/pseries/cmm: call balloon_devinfo_init() also without CONFIG_BALLOON_COMPACTION

[Ritesh Harjani]

David Hildenbrand <david@redhat.com> writes:

> 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.
>

Agreed cmm uses balloon_dev_info infrastructure beyond just
CONFIG_BALLOON_COMPACTION, so it should be initialized by default.

The patch looks good to me. Please feel free to add:

Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>

[PATCH v1 2/2] powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages

[David Hildenbrand]

Let's properly adjust BALLOON_MIGRATE like the other drivers.

Note that the INFLATE/DEFLATE events are triggered from the core when
enqueueing/dequeueing pages.

Not completely sure whether really is stable material, but the fix is
trivial so let's just CC stable.

This was found by code inspection.

Fixes: fe030c9b85e6 ("powerpc/pseries/cmm: Implement balloon compaction")
Cc: <stable@vger.kernel.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 arch/powerpc/platforms/pseries/cmm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c
index 688f5fa1c7245..310dab4bc8679 100644
--- a/arch/powerpc/platforms/pseries/cmm.c
+++ b/arch/powerpc/platforms/pseries/cmm.c
@@ -532,6 +532,7 @@ static int cmm_migratepage(struct balloon_dev_info *b_dev_info,
 
 	spin_lock_irqsave(&b_dev_info->pages_lock, flags);
 	balloon_page_insert(b_dev_info, newpage);
+	__count_vm_event(BALLOON_MIGRATE);
 	b_dev_info->isolated_pages--;
 	spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);
 
-- 
2.51.0

Re: [PATCH v1 2/2] powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages

[Ritesh Harjani]

David Hildenbrand <david@redhat.com> writes:

> Let's properly adjust BALLOON_MIGRATE like the other drivers.
>
> Note that the INFLATE/DEFLATE events are triggered from the core when
> enqueueing/dequeueing pages.
>
> Not completely sure whether really is stable material, but the fix is
> trivial so let's just CC stable.
>
> This was found by code inspection.
>
> Fixes: fe030c9b85e6 ("powerpc/pseries/cmm: Implement balloon compaction")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  arch/powerpc/platforms/pseries/cmm.c | 1 +
>  1 file changed, 1 insertion(+)

Make sense to add vmstat counter for BALLOON_MIGRATE as well.
The changes looks good to me. Please feel free to add:

Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>