The patch titled Subject: mm,ksm: swapoff might need to copy has been removed from the -mm tree. Its filename was mmksm-swapoff-might-need-to-copy.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Hugh Dickins <hughd@xxxxxxxxxx> Subject: mm,ksm: swapoff might need to copy Before establishing that KSM page migration was the cause of my WARN_ON_ONCE(page_mapped(page))s, I suspected that they came from the lack of a ksm_might_need_to_copy() in swapoff's unuse_pte() - which in many respects is equivalent to faulting in a page. In fact I've never caught that as the cause: but in theory it does at least need the KSM_RUN_UNMERGE check in ksm_might_need_to_copy(), to avoid bringing a KSM page back in when it's not supposed to be. I intended to copy how it's done in do_swap_page(), but have a strong aversion to how "swapcache" ends up being used there: rework it with "page != swapcache". Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Petr Holasek <pholasek@xxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Izik Eidus <izik.eidus@xxxxxxxxxxxxxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/swapfile.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff -puN mm/swapfile.c~mmksm-swapoff-might-need-to-copy mm/swapfile.c --- a/mm/swapfile.c~mmksm-swapoff-might-need-to-copy +++ a/mm/swapfile.c @@ -874,11 +874,17 @@ unsigned int count_swap_pages(int type, static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, swp_entry_t entry, struct page *page) { + struct page *swapcache; struct mem_cgroup *memcg; spinlock_t *ptl; pte_t *pte; int ret = 1; + swapcache = page; + page = ksm_might_need_to_copy(page, vma, addr); + if (unlikely(!page)) + return -ENOMEM; + if (mem_cgroup_try_charge_swapin(vma->vm_mm, page, GFP_KERNEL, &memcg)) { ret = -ENOMEM; @@ -897,7 +903,10 @@ static int unuse_pte(struct vm_area_stru get_page(page); set_pte_at(vma->vm_mm, addr, pte, pte_mkold(mk_pte(page, vma->vm_page_prot))); - page_add_anon_rmap(page, vma, addr); + if (page == swapcache) + page_add_anon_rmap(page, vma, addr); + else /* ksm created a completely new copy */ + page_add_new_anon_rmap(page, vma, addr); mem_cgroup_commit_charge_swapin(page, memcg); swap_free(entry); /* @@ -908,6 +917,10 @@ static int unuse_pte(struct vm_area_stru out: pte_unmap_unlock(pte, ptl); out_nolock: + if (page != swapcache) { + unlock_page(page); + put_page(page); + } return ret; } _ Patches currently in -mm which might be from hughd@xxxxxxxxxx are origin.patch revert-x86-mm-make-spurious_fault-check-explicitly-check-the-present-bit.patch pageattr-prevent-pse-and-gloabl-leftovers-to-confuse-pmd-pte_present-and-pmd_huge.patch mm-accelerate-munlock-treatment-of-thp-pages.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html