On Mon, 7 Mar 2022 09:24:58 +0100 David Hildenbrand <david@xxxxxxxxxx> wrote: > On 07.03.22 03:07, Andrew Morton wrote: > > On Fri, 4 Mar 2022 19:50:08 +0100 David Hildenbrand <david@xxxxxxxxxx> wrote: > > > >> @Andrew, the last mail I received was > >> > >> + mm-huge_memory-remove-stale-locking-logic-from-__split_huge_pmd.patch > >> added to -mm tree > >> > >> The patch shows up in mmotm as > >> > >> #[merged]mm-huge_memory-remove-stale-locking-logic-from-__split_huge_pmd.patch > >> > >> ... which shouldn't be true. > > > > I guess I mislabelled the reason for dropping it. Should have been to-be-updated, > > due to https://lkml.kernel.org/r/CAHbLzkpbnQyHRckoRtbZoaLvANu92MY4kEsbKudaQ8MDUA3nVg@xxxxxxxxxxxxxx > > > > Let me clarify. > > 1. I sent [1] (9 patches) > > 2. You queued the 9 patches > > E.g., in "mmotm 2022-02-15-20-22 uploaded" > > * mm-optimize-do_wp_page-for-exclusive-pages-in-the-swapcache.patch > * mm-optimize-do_wp_page-for-fresh-pages-in-local-lru-pagevecs.patch > * mm-slightly-clarify-ksm-logic-in-do_swap_page.patch > * mm-streamline-cow-logic-in-do_swap_page.patch > * mm-huge_memory-streamline-cow-logic-in-do_huge_pmd_wp_page.patch > * mm-khugepaged-remove-reuse_swap_page-usage.patch > * mm-swapfile-remove-stale-reuse_swap_page.patch > * mm-huge_memory-remove-stale-page_trans_huge_mapcount.patch > * mm-huge_memory-remove-stale-locking-logic-from-__split_huge_pmd.patch > > 3. The last patch in the series was dropped. What remains are 8 patches. > > E.g., in "mmotm 2022-02-24-22-38 uploaded" > > * mm-optimize-do_wp_page-for-exclusive-pages-in-the-swapcache.patch > * mm-optimize-do_wp_page-for-fresh-pages-in-local-lru-pagevecs.patch > * mm-slightly-clarify-ksm-logic-in-do_swap_page.patch > * mm-streamline-cow-logic-in-do_swap_page.patch > * mm-huge_memory-streamline-cow-logic-in-do_huge_pmd_wp_page.patch > * mm-khugepaged-remove-reuse_swap_page-usage.patch > * mm-swapfile-remove-stale-reuse_swap_page.patch > * mm-huge_memory-remove-stale-page_trans_huge_mapcount.patch > > 4. Yang Shi sent his patch (the one we're replying to) > > 5. You picked his patch and dropped it again due to [2] > > > I'm wondering why 3 happened and why > https://www.ozlabs.org/~akpm/mmotm/series contains: > > > mm-optimize-do_wp_page-for-exclusive-pages-in-the-swapcache.patch > mm-optimize-do_wp_page-for-fresh-pages-in-local-lru-pagevecs.patch > mm-slightly-clarify-ksm-logic-in-do_swap_page.patch > mm-streamline-cow-logic-in-do_swap_page.patch > mm-huge_memory-streamline-cow-logic-in-do_huge_pmd_wp_page.patch > mm-khugepaged-remove-reuse_swap_page-usage.patch > mm-swapfile-remove-stale-reuse_swap_page.patch > mm-huge_memory-remove-stale-page_trans_huge_mapcount.patch > ... > #[merged]mm-huge_memory-remove-stale-locking-logic-from-__split_huge_pmd.patch OK, thanks. I guess it was me seeing 100% rejects when merging onto the folio changes then incorrectly deciding the patch was now in linux-next via some other tree. I restored it and fixed things up. Please check. --- a/mm/huge_memory.c~mm-huge_memory-remove-stale-locking-logic-from-__split_huge_pmd +++ a/mm/huge_memory.c @@ -2133,8 +2133,6 @@ void __split_huge_pmd(struct vm_area_str { spinlock_t *ptl; struct mmu_notifier_range range; - bool do_unlock_folio = false; - pmd_t _pmd; mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm, address & HPAGE_PMD_MASK, @@ -2153,42 +2151,14 @@ void __split_huge_pmd(struct vm_area_str goto out; } -repeat: if (pmd_trans_huge(*pmd)) { - if (!folio) { + if (!folio) folio = page_folio(pmd_page(*pmd)); - /* - * An anonymous page must be locked, to ensure that a - * concurrent reuse_swap_page() sees stable mapcount; - * but reuse_swap_page() is not used on shmem or file, - * and page lock must not be taken when zap_pmd_range() - * calls __split_huge_pmd() while i_mmap_lock is held. - */ - if (folio_test_anon(folio)) { - if (unlikely(!folio_trylock(folio))) { - folio_get(folio); - _pmd = *pmd; - spin_unlock(ptl); - folio_lock(folio); - spin_lock(ptl); - if (unlikely(!pmd_same(*pmd, _pmd))) { - folio_unlock(folio); - folio_put(folio); - folio = NULL; - goto repeat; - } - folio_put(folio); - } - do_unlock_folio = true; - } - } } else if (!(pmd_devmap(*pmd) || is_pmd_migration_entry(*pmd))) goto out; __split_huge_pmd_locked(vma, pmd, range.start, freeze); out: spin_unlock(ptl); - if (do_unlock_folio) - folio_unlock(folio); /* * No need to double call mmu_notifier->invalidate_range() callback. * They are 3 cases to consider inside __split_huge_pmd_locked(): _
