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 + */