On Mon, Mar 7, 2022 at 3:43 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > 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. Thanks, Andrew. I think we could clean it up a little bit further. > > > --- 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)); We could remove the "if (pmd_trans_huge(*pmd))" section since folio is actually not used afterward at all. > - /* > - * 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); With the above if removed, this could be changed to: if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd) || is_pmd_migration_entry(*pmd)) __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(): > _ >
