kernel/git/next/linux-next.git/mm/khugepaged.c, branch akpm-base

mm/khugepaged: try to free transhuge swapcache when possible

2022-06-27T20:45:42+00:00

Transhuge swapcaches won't be freed in __collapse_huge_page_copy(). It's because release_pte_page() is not called for these pages and thus free_page_and_swap_cache can't grab the page lock. These pages won't be freed from swap cache even if we are the only user until next time reclaim. It shouldn't hurt indeed, but we could try to free these pages to save more memory for system. Link: https://lkml.kernel.org/r/20220625092816.4856-8-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Cc: Alistair Popple Cc: Andrea Arcangeli Cc: David Hildenbrand Cc: David Howells Cc: Matthew Wilcox (Oracle) Cc: NeilBrown Cc: Peter Xu Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Yang Shi Cc: Zach O'Keefe Signed-off-by: Andrew Morton

mm/khugepaged: remove unneeded return value of khugepaged_add_pte_mapped_thp()

2022-06-27T20:45:42+00:00

The return value of khugepaged_add_pte_mapped_thp() is always 0 and also ignored. Remove it to clean up the code. Link: https://lkml.kernel.org/r/20220625092816.4856-7-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Reviewed-by: Zach O'Keefe Reviewed-by: Yang Shi Cc: Alistair Popple Cc: Andrea Arcangeli Cc: David Hildenbrand Cc: David Howells Cc: Matthew Wilcox (Oracle) Cc: NeilBrown Cc: Peter Xu Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm/khugepaged: use helper macro __ATTR_RW

2022-06-27T20:45:42+00:00

Use helper macro __ATTR_RW to define the khugepaged attributes. Minor readability improvement. Link: https://lkml.kernel.org/r/20220625092816.4856-6-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Reviewed-by: Yang Shi Cc: Alistair Popple Cc: Andrea Arcangeli Cc: David Hildenbrand Cc: David Howells Cc: Matthew Wilcox (Oracle) Cc: NeilBrown Cc: Peter Xu Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Zach O'Keefe Signed-off-by: Andrew Morton

mm/khugepaged: minor cleanup for collapse_file

2022-06-27T20:45:42+00:00

nr_none is always 0 for non-shmem case because the page can be read from the backend store. So when nr_none ! = 0, it must be in is_shmem case. Also only adjust the nrpages and uncharge shmem when nr_none != 0 to save cpu cycles. Link: https://lkml.kernel.org/r/20220625092816.4856-5-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Reviewed-by: Zach O'Keefe Cc: Alistair Popple Cc: Andrea Arcangeli Cc: David Hildenbrand Cc: David Howells Cc: Matthew Wilcox (Oracle) Cc: NeilBrown Cc: Peter Xu Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Yang Shi Signed-off-by: Andrew Morton

mm/khugepaged: trivial typo and codestyle cleanup

2022-06-27T20:45:42+00:00

Fix some typos and tweak the code to meet codestyle. No functional change intended. Link: https://lkml.kernel.org/r/20220625092816.4856-4-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Reviewed-by: Zach O'Keefe Reviewed-by: Yang Shi Cc: Alistair Popple Cc: Andrea Arcangeli Cc: David Hildenbrand Cc: David Howells Cc: Matthew Wilcox (Oracle) Cc: NeilBrown Cc: Peter Xu Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm/khugepaged: stop swapping in page when VM_FAULT_RETRY occurs

2022-06-27T20:45:42+00:00

When do_swap_page returns VM_FAULT_RETRY, we do not retry here and thus swap entry will remain in pagetable. This will result in later failure. So stop swapping in pages in this case to save cpu cycles. As A further optimization, mmap_lock is released when __collapse_huge_page_swapin() fails to avoid relocking mmap_lock. And "swapped_in++" is moved after error handling to make it more accurate. Link: https://lkml.kernel.org/r/20220625092816.4856-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Cc: Alistair Popple Cc: Andrea Arcangeli Cc: David Hildenbrand Cc: David Howells Cc: Matthew Wilcox (Oracle) Cc: NeilBrown Cc: Peter Xu Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Yang Shi Cc: Zach O'Keefe Signed-off-by: Andrew Morton

mm/khugepaged: remove unneeded shmem_huge_enabled() check

2022-06-27T20:45:41+00:00

Patch series "A few cleanup patches for khugepaged", v2. This series contains a few cleaup patches to remove unneeded return value, use helper macro, fix typos and so on. More details can be found in the respective changelogs. This patch (of 7): If we reach here, khugepaged_scan_mm_slot() has already made sure that hugepage is enabled for shmem, via its call to hugepage_vma_check(). Remove this duplicated check. Link: https://lkml.kernel.org/r/20220625092816.4856-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220625092816.4856-2-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Reviewed-by: Yang Shi Reviewed-by: Zach O'Keefe Cc: Andrea Arcangeli Cc: Matthew Wilcox (Oracle) Cc: Vlastimil Babka Cc: David Howells Cc: NeilBrown Cc: Alistair Popple Cc: David Hildenbrand Cc: Suren Baghdasaryan Cc: Peter Xu Signed-off-by: Andrew Morton

mm: khugepaged: reorg some khugepaged helpers

2022-06-27T20:45:28+00:00

The khugepaged_{enabled|always|req_madv} are not khugepaged only anymore, move them to huge_mm.h and rename to hugepage_flags_xxx, and remove khugepaged_req_madv due to no users. Also move khugepaged_defrag to khugepaged.c since its only caller is in that file, it doesn't have to be in a header file. Link: https://lkml.kernel.org/r/20220616174840.1202070-7-shy828301@gmail.com Signed-off-by: Yang Shi Reviewed-by: Zach O'Keefe Cc: Kirill A. Shutemov Cc: Matthew Wilcox Cc: Miaohe Lin Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm: thp: kill __transhuge_page_enabled()

2022-06-27T20:45:28+00:00

The page fault path checks THP eligibility with __transhuge_page_enabled() which does the similar thing as hugepage_vma_check(), so use hugepage_vma_check() instead. However page fault allows DAX and !anon_vma cases, so added a new flag, in_pf, to hugepage_vma_check() to make page fault work correctly. The in_pf flag is also used to skip shmem and file THP for page fault since shmem handles THP in its own shmem_fault() and file THP allocation on fault is not supported yet. Also remove hugepage_vma_enabled() since hugepage_vma_check() is the only caller now, it is not necessary to have a helper function. Link: https://lkml.kernel.org/r/20220616174840.1202070-6-shy828301@gmail.com Signed-off-by: Yang Shi Reviewed-by: Zach O'Keefe Cc: Kirill A. Shutemov Cc: Matthew Wilcox Cc: Miaohe Lin Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm: thp: kill transparent_hugepage_active()

2022-06-27T20:45:28+00:00

The transparent_hugepage_active() was introduced to show THP eligibility bit in smaps in proc, smaps is the only user. But it actually does the similar check as hugepage_vma_check() which is used by khugepaged. We definitely don't have to maintain two similar checks, so kill transparent_hugepage_active(). This patch also fixed the wrong behavior for VM_NO_KHUGEPAGED vmas. Also move hugepage_vma_check() to huge_memory.c and huge_mm.h since it is not only for khugepaged anymore. Link: https://lkml.kernel.org/r/20220616174840.1202070-5-shy828301@gmail.com Signed-off-by: Yang Shi Reviewed-by: Zach O'Keefe Cc: Kirill A. Shutemov Cc: Matthew Wilcox Cc: Miaohe Lin Cc: Vlastimil Babka Signed-off-by: Andrew Morton