Re: [PATCH v1 1/3] mm/ksm: unmerge and clear VM_MERGEABLE when setting PR_SET_MEMORY_MERGE=0

From: David Hildenbrand
Date: Fri Apr 21 2023 - 13:23:07 EST


I understand we want to keep the name "symmetric" with
ksm_enable_merge_any, but it also unmerges the ksm pages. Do we want to
reflect that in the function name?

ksm_disable_merge_any_umerge() is suboptimal.

As ksm_disable_merge_any() now reverts what ksm_enable_merge_any() ended
up doing, I think it's just fine.

(it would be a different story if we'd be using "set" / "clear"
terminology instead of "enable" / "disable").

We can describe that in the comment.


Can we add a comment for the function?

Can do for symmetry with ksm_enable_merge_any().


+/**
+ * ksm_disable_merge_any - Disable merging on all compatible VMA's of the mm,
+ * previously enabled via ksm_enable_merge_any().
+ *
+ * Disabling merging implies unmerging any merged pages, like setting
+ * MADV_UNMERGEABLE would. If unmerging fails, the whole operation fails and
+ * merging on all compatible VMA's remains enabled.
+ *
+ * @mm: Pointer to mm
+ *
+ * Returns 0 on success, otherwise error code
+ */


--
Thanks,

David / dhildenb