Ping. Just want to get comments on THP migration part (Patch 4-14). If they look OK, I can rebase THP migration part on mmotm-2017-02-22-16-28 and send them out for merging. Thanks. Zi Yan wrote: > From: Zi Yan <ziy@xxxxxxxxxx> > > Hi all, > > The patches are rebased on mmotm-2017-02-01-15-35 with feedbacks from > Naoya Horiguchi's v2 patches. > > I fix a bug in zap_pmd_range() and include the fixes in Patches 1-3. > The racy check in zap_pmd_range() can miss pmd_protnone and pmd_migration_entry, > which leads to PTE page table not freed. > > In Patch 4, I move _PAGE_SWP_SOFT_DIRTY to bit 1. Because bit 6 (used in v2) > can be set by some CPUs by mistake and the new swap entry format does not use > bit 1-4. > > I also adjust two core migration functions, set_pmd_migration_entry() and > remove_migration_pmd(), to use Kirill A. Shutemov's page_vma_mapped_walk() > function. Patch 8 needs Kirill's comments, since I also add changes > to his page_vma_mapped_walk() function with pmd_migration_entry handling. > > In Patch 8, I replace pmdp_huge_get_and_clear() with pmdp_huge_clear_flush() > in set_pmd_migration_entry() to avoid data corruption after page migration. > > In Patch 9, I include is_pmd_migration_entry() in pmd_none_or_trans_huge_or_clear_bad(). > Otherwise, a pmd_migration_entry is treated as pmd_bad and cleared, which > leads to deposited PTE page table not freed. > > I personally use this patchset with my customized kernel to test frequent > page migrations by replacing page reclaim with page migration. > The bugs fixed in Patches 1-3 and 8 was discovered while I am testing my kernel. > I did a 16-hour stress test that has ~7 billion total page migrations. > No error or data corruption was found. > > > General description > =========================================== > > This patchset enhances page migration functionality to handle thp migration > for various page migration's callers: > - mbind(2) > - move_pages(2) > - migrate_pages(2) > - cgroup/cpuset migration > - memory hotremove > - soft offline > > The main benefit is that we can avoid unnecessary thp splits, which helps us > avoid performance decrease when your applications handles NUMA optimization on > their own. > > The implementation is similar to that of normal page migration, the key point > is that we modify a pmd to a pmd migration entry in swap-entry like format. > > > Any comments or advices are welcomed. > > Best Regards, > Yan Zi > > Naoya Horiguchi (11): > mm: x86: move _PAGE_SWP_SOFT_DIRTY from bit 7 to bit 1 > mm: mempolicy: add queue_pages_node_check() > mm: thp: introduce separate TTU flag for thp freezing > mm: thp: introduce CONFIG_ARCH_ENABLE_THP_MIGRATION > mm: thp: enable thp migration in generic path > mm: thp: check pmd migration entry in common path > mm: soft-dirty: keep soft-dirty bits over thp migration > mm: hwpoison: soft offline supports thp migration > mm: mempolicy: mbind and migrate_pages support thp migration > mm: migrate: move_pages() supports thp migration > mm: memory_hotplug: memory hotremove supports thp migration > > Zi Yan (3): > mm: thp: make __split_huge_pmd_locked visible. > mm: thp: create new __zap_huge_pmd_locked function. > mm: use pmd lock instead of racy checks in zap_pmd_range() > > arch/x86/Kconfig | 4 + > arch/x86/include/asm/pgtable.h | 17 ++ > arch/x86/include/asm/pgtable_64.h | 2 + > arch/x86/include/asm/pgtable_types.h | 10 +- > arch/x86/mm/gup.c | 4 +- > fs/proc/task_mmu.c | 37 +++-- > include/asm-generic/pgtable.h | 105 ++++-------- > include/linux/huge_mm.h | 36 ++++- > include/linux/rmap.h | 1 + > include/linux/swapops.h | 146 ++++++++++++++++- > mm/Kconfig | 3 + > mm/gup.c | 20 ++- > mm/huge_memory.c | 302 +++++++++++++++++++++++++++++------ > mm/madvise.c | 2 + > mm/memcontrol.c | 2 + > mm/memory-failure.c | 31 ++-- > mm/memory.c | 33 ++-- > mm/memory_hotplug.c | 17 +- > mm/mempolicy.c | 124 ++++++++++---- > mm/migrate.c | 66 ++++++-- > mm/mprotect.c | 6 +- > mm/mremap.c | 2 +- > mm/page_vma_mapped.c | 13 +- > mm/pagewalk.c | 2 + > mm/pgtable-generic.c | 3 +- > mm/rmap.c | 21 ++- > 26 files changed, 770 insertions(+), 239 deletions(-) > -- Best Regards, Yan Zi
Attachment:
signature.asc
Description: OpenPGP digital signature
