Patch "powerpc/hugetlb: Call mm_dec_nr_pmds() in hugetlb_free_pmd_range()" has been added to the 4.0-stable tree

This is a note to let you know that I've just added the patch titled

powerpc/hugetlb: Call mm_dec_nr_pmds() in hugetlb_free_pmd_range()

to the 4.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
powerpc-hugetlb-call-mm_dec_nr_pmds-in-hugetlb_free_pmd_range.patch
and it can be found in the queue-4.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Scott Wood <[email protected]>
Date: Fri, 10 Apr 2015 19:37:34 -0500
Subject: powerpc/hugetlb: Call mm_dec_nr_pmds() in hugetlb_free_pmd_range()

From: Scott Wood <[email protected]>

commit 50c6a665b383cb5839e45d04e36faeeefaffa052 upstream.

Commit dc6c9a35b66b5 ("mm: account pmd page tables to the process") added a counter that is incremented whenever a PMD is allocated and decremented whenever a PMD is freed. For hugepages on PPC, common code is used to allocated PMDs, but arch-specific code is used to free PMDs.

This results in kernel output such as "BUG: non-zero nr_pmds on freeing
mm: 1" when using hugepages.

Update the PPC hugepage PMD freeing code to decrement the count, just as the above commit did for free_pmd_range().

---
 arch/powerpc/mm/hugetlbpage.c |    1 +
 1 file changed, 1 insertion(+)

@@ -581,6 +581,7 @@ static void hugetlb_free_pmd_range(struc
 	pmd = pmd_offset(pud, start);
 	pud_clear(pud);
 	pmd_free_tlb(tlb, pmd, start);
+	mm_dec_nr_pmds(tlb->mm);
 }
 
 static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,

Patches currently in stable-queue which might be from [email protected] are

queue-4.0/powerpc-hugetlb-call-mm_dec_nr_pmds-in-hugetlb_free_pmd_range.patch