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2022-10-03mm: use nth_page instead of mem_map_offset mem_map_nextCheng Li
To handle the discontiguous case, mem_map_next() has a parameter named `offset`. As a function caller, one would be confused why "get next entry" needs a parameter named "offset". The other drawback of mem_map_next() is that the callers must take care of the map between parameter "iter" and "offset", otherwise we may get an hole or duplication during iteration. So we use nth_page instead of mem_map_next. And replace mem_map_offset with nth_page() per Matthew's comments. Link: https://lkml.kernel.org/r/1662708669-9395-1-git-send-email-lic121@chinatelecom.cn Signed-off-by: Cheng Li <lic121@chinatelecom.cn> Fixes: 69d177c2fc70 ("hugetlbfs: handle pages higher order than MAX_ORDER") Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm/hugetlb.c: remove unnecessary initialization of local `err'Li zeming
Link: https://lkml.kernel.org/r/20220905020918.3552-1-zeming@nfschina.com Signed-off-by: Li zeming <zeming@nfschina.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26Merge branch 'mm-hotfixes-stable' into mm-stableAndrew Morton
2022-09-26mm/hugetlb: correct demote page offset logicDoug Berger
With gigantic pages it may not be true that struct page structures are contiguous across the entire gigantic page. The nth_page macro is used here in place of direct pointer arithmetic to correct for this. Mike said: : This error could cause addressing exceptions. However, this is only : possible in configurations where CONFIG_SPARSEMEM && : !CONFIG_SPARSEMEM_VMEMMAP. Such a configuration option is rare and : unknown to be the default anywhere. Link: https://lkml.kernel.org/r/20220914190917.3517663-1-opendmb@gmail.com Fixes: 8531fc6f52f5 ("hugetlb: add hugetlb demote page support") Signed-off-by: Doug Berger <opendmb@gmail.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11hugetlb: remove meaningless BUG_ON(huge_pte_none())Miaohe Lin
When code reaches here, invalid page would have been accessed if huge pte is none. So this BUG_ON(huge_pte_none()) is meaningless. Remove it. Link: https://lkml.kernel.org/r/20220901120030.63318-10-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11hugetlb: add comment for subtle SetHPageVmemmapOptimized()Miaohe Lin
The SetHPageVmemmapOptimized() called here seems unnecessary as it's assumed to be set when calling this function. But it's indeed cleared by above set_page_private(page, 0). Add a comment to avoid possible future confusion. Link: https://lkml.kernel.org/r/20220901120030.63318-9-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11hugetlb: kill hugetlbfs_pagecache_page()Miaohe Lin
Fold hugetlbfs_pagecache_page() into its sole caller to remove some duplicated code. No functional change intended. Link: https://lkml.kernel.org/r/20220901120030.63318-8-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11hugetlb: pass NULL to kobj_to_hstate() if nid is unusedMiaohe Lin
We can pass NULL to kobj_to_hstate() directly when nid is unused to simplify the code. No functional change intended. Link: https://lkml.kernel.org/r/20220901120030.63318-7-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11hugetlb: use helper {huge_pte|pmd}_lock()Miaohe Lin
Use helper huge_pte_lock and pmd_lock to simplify the code. No functional change intended. Link: https://lkml.kernel.org/r/20220901120030.63318-6-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11hugetlb: use sizeof() to get the array sizeMiaohe Lin
It's better to use sizeof() to get the array size instead of manual calculation. Minor readability improvement. Link: https://lkml.kernel.org/r/20220901120030.63318-5-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11hugetlb: use LIST_HEAD() to define a list headMiaohe Lin
Use LIST_HEAD() directly to define a list head to simplify the code. No functional change intended. Link: https://lkml.kernel.org/r/20220901120030.63318-4-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11hugetlb: Use helper macro SZ_1KMiaohe Lin
Use helper macro SZ_1K to do the size conversion to make code more consistent in this file. Minor readability improvement. Link: https://lkml.kernel.org/r/20220901120030.63318-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11hugetlb: make hugetlb_cma_check() staticMiaohe Lin
Patch series "A few cleanup patches for hugetlb", v2. This series contains a few cleanup patches to use helper functions to simplify the codes, remove unneeded nid parameter and so on. More details can be found in the respective changelogs. This patch (of 10): Make hugetlb_cma_check() static as it's only used inside mm/hugetlb.c. Link: https://lkml.kernel.org/r/20220901120030.63318-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220901120030.63318-2-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm/hugetlb: make detecting shared pte more reliableMiaohe Lin
If the pagetables are shared, we shouldn't copy or take references. Since src could have unshared and dst shares with another vma, huge_pte_none() is thus used to determine whether dst_pte is shared. But this check isn't reliable. A shared pte could have pte none in pagetable in fact. The page count of ptep page should be checked here in order to reliably determine whether pte is shared. [lukas.bulwahn@gmail.com: remove unused local variable dst_entry in copy_hugetlb_page_range()] Link: https://lkml.kernel.org/r/20220822082525.26071-1-lukas.bulwahn@gmail.com Link: https://lkml.kernel.org/r/20220816130553.31406-7-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm/hugetlb: fix sysfs group leak in hugetlb_unregister_node()Miaohe Lin
The sysfs group per_node_hstate_attr_group and hstate_demote_attr_group when h->demote_order != 0 are created in hugetlb_register_node(). But these sysfs groups are not removed when unregister the node, thus sysfs group is leaked. Using sysfs_remove_group() to fix this issue. Link: https://lkml.kernel.org/r/20220816130553.31406-6-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Fengwei Yin <fengwei.yin@intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm/hugetlb: fix missing call to restore_reserve_on_error()Miaohe Lin
When huge_add_to_page_cache() fails, the page is freed directly without calling restore_reserve_on_error() to restore reserve for newly allocated pages not in page cache. Fix this by calling restore_reserve_on_error() when huge_add_to_page_cache fails. [linmiaohe@huawei.com: remove err == -EEXIST check and retry logic] Link: https://lkml.kernel.org/r/20220823030209.57434-4-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220816130553.31406-4-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm/hugetlb: fix WARN_ON(!kobj) in sysfs_create_group()Miaohe Lin
If sysfs_create_group() fails with hstate_attr_group, hstate_kobjs[hi] will be set to NULL. Then it will be passed to sysfs_create_group() if h->demote_order != 0 thus triggering WARN_ON(!kobj) check. Fix this by making sure hstate_kobjs[hi] != NULL when calling sysfs_create_group. Link: https://lkml.kernel.org/r/20220816130553.31406-3-linmiaohe@huawei.com Fixes: 79dfc695525f ("hugetlb: add demote hugetlb page sysfs interfaces") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm/hugetlb: fix incorrect update of max_huge_pagesMiaohe Lin
Patch series "A few fixup patches for hugetlb". This series contains a few fixup patches to fix incorrect update of max_huge_pages, fix WARN_ON(!kobj) in sysfs_create_group() and so on. More details can be found in the respective changelogs. This patch (of 6): There should be pages_per_huge_page(h) / pages_per_huge_page(target_hstate) pages incremented for target_hstate->max_huge_pages when page is demoted. Update max_huge_pages accordingly for consistency. Link: https://lkml.kernel.org/r/20220816130553.31406-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220816130553.31406-2-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm/hugetlb: add dedicated func to get 'allowed' nodemask for current processFeng Tang
Muchun Song found that after MPOL_PREFERRED_MANY policy was introduced in commit b27abaccf8e8 ("mm/mempolicy: add MPOL_PREFERRED_MANY for multiple preferred nodes"), the policy_nodemask_current()'s semantics for this new policy has been changed, which returns 'preferred' nodes instead of 'allowed' nodes. With the changed semantic of policy_nodemask_current, a task with MPOL_PREFERRED_MANY policy could fail to get its reservation even though it can fall back to other nodes (either defined by cpusets or all online nodes) for that reservation failing mmap calles unnecessarily early. The fix is to not consider MPOL_PREFERRED_MANY for reservations at all because they, unlike MPOL_MBIND, do not pose any actual hard constrain. Michal suggested the policy_nodemask_current() is only used by hugetlb, and could be moved to hugetlb code with more explicit name to enforce the 'allowed' semantics for which only MPOL_BIND policy matters. apply_policy_zone() is made extern to be called in hugetlb code and its return value is changed to bool. [1]. https://lore.kernel.org/lkml/20220801084207.39086-1-songmuchun@bytedance.com/t/ Link: https://lkml.kernel.org/r/20220805005903.95563-1-feng.tang@intel.com Fixes: b27abaccf8e8 ("mm/mempolicy: add MPOL_PREFERRED_MANY for multiple preferred nodes") Signed-off-by: Feng Tang <feng.tang@intel.com> Reported-by: Muchun Song <songmuchun@bytedance.com> Suggested-by: Michal Hocko <mhocko@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Ben Widawsky <bwidawsk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-28mm/hugetlb: avoid corrupting page->mapping in hugetlb_mcopy_atomic_pteMiaohe Lin
In MCOPY_ATOMIC_CONTINUE case with a non-shared VMA, pages in the page cache are installed in the ptes. But hugepage_add_new_anon_rmap is called for them mistakenly because they're not vm_shared. This will corrupt the page->mapping used by page cache code. Link: https://lkml.kernel.org/r/20220712130542.18836-1-linmiaohe@huawei.com Fixes: f619147104c8 ("userfaultfd: add UFFDIO_CONTINUE ioctl") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-20mm/hugetlb: support write-faults in shared mappingsDavid Hildenbrand
If we ever get a write-fault on a write-protected page in a shared mapping, we'd be in trouble (again). Instead, we can simply map the page writable. And in fact, there is even a way right now to trigger that code via uffd-wp ever since we stared to support it for shmem in 5.19: -------------------------------------------------------------------------- #include <stdio.h> #include <stdlib.h> #include <string.h> #include <fcntl.h> #include <unistd.h> #include <errno.h> #include <sys/mman.h> #include <sys/syscall.h> #include <sys/ioctl.h> #include <linux/userfaultfd.h> #define HUGETLB_SIZE (2 * 1024 * 1024u) static char *map; int uffd; static int temp_setup_uffd(void) { struct uffdio_api uffdio_api; struct uffdio_register uffdio_register; struct uffdio_writeprotect uffd_writeprotect; struct uffdio_range uffd_range; uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY); if (uffd < 0) { fprintf(stderr, "syscall() failed: %d\n", errno); return -errno; } uffdio_api.api = UFFD_API; uffdio_api.features = UFFD_FEATURE_PAGEFAULT_FLAG_WP; if (ioctl(uffd, UFFDIO_API, &uffdio_api) < 0) { fprintf(stderr, "UFFDIO_API failed: %d\n", errno); return -errno; } if (!(uffdio_api.features & UFFD_FEATURE_PAGEFAULT_FLAG_WP)) { fprintf(stderr, "UFFD_FEATURE_WRITEPROTECT missing\n"); return -ENOSYS; } /* Register UFFD-WP */ uffdio_register.range.start = (unsigned long) map; uffdio_register.range.len = HUGETLB_SIZE; uffdio_register.mode = UFFDIO_REGISTER_MODE_WP; if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) < 0) { fprintf(stderr, "UFFDIO_REGISTER failed: %d\n", errno); return -errno; } /* Writeprotect a single page. */ uffd_writeprotect.range.start = (unsigned long) map; uffd_writeprotect.range.len = HUGETLB_SIZE; uffd_writeprotect.mode = UFFDIO_WRITEPROTECT_MODE_WP; if (ioctl(uffd, UFFDIO_WRITEPROTECT, &uffd_writeprotect)) { fprintf(stderr, "UFFDIO_WRITEPROTECT failed: %d\n", errno); return -errno; } /* Unregister UFFD-WP without prior writeunprotection. */ uffd_range.start = (unsigned long) map; uffd_range.len = HUGETLB_SIZE; if (ioctl(uffd, UFFDIO_UNREGISTER, &uffd_range)) { fprintf(stderr, "UFFDIO_UNREGISTER failed: %d\n", errno); return -errno; } return 0; } int main(int argc, char **argv) { int fd; fd = open("/dev/hugepages/tmp", O_RDWR | O_CREAT); if (!fd) { fprintf(stderr, "open() failed\n"); return -errno; } if (ftruncate(fd, HUGETLB_SIZE)) { fprintf(stderr, "ftruncate() failed\n"); return -errno; } map = mmap(NULL, HUGETLB_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); if (map == MAP_FAILED) { fprintf(stderr, "mmap() failed\n"); return -errno; } *map = 0; if (temp_setup_uffd()) return 1; *map = 0; return 0; } -------------------------------------------------------------------------- Above test fails with SIGBUS when there is only a single free hugetlb page. # echo 1 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages # ./test Bus error (core dumped) And worse, with sufficient free hugetlb pages it will map an anonymous page into a shared mapping, for example, messing up accounting during unmap and breaking MAP_SHARED semantics: # echo 2 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages # ./test # cat /proc/meminfo | grep HugePages_ HugePages_Total: 2 HugePages_Free: 1 HugePages_Rsvd: 18446744073709551615 HugePages_Surp: 0 Reason is that uffd-wp doesn't clear the uffd-wp PTE bit when unregistering and consequently keeps the PTE writeprotected. Reason for this is to avoid the additional overhead when unregistering. Note that this is the case also for !hugetlb and that we will end up with writable PTEs that still have the uffd-wp PTE bit set once we return from hugetlb_wp(). I'm not touching the uffd-wp PTE bit for now, because it seems to be a generic thing -- wp_page_reuse() also doesn't clear it. VM_MAYSHARE handling in hugetlb_fault() for FAULT_FLAG_WRITE indicates that MAP_SHARED handling was at least envisioned, but could never have worked as expected. While at it, make sure that we never end up in hugetlb_wp() on write faults without VM_WRITE, because we don't support maybe_mkwrite() semantics as commonly used in the !hugetlb case -- for example, in wp_page_reuse(). Note that there is no need to do any kind of reservation in hugetlb_fault() in this case ... because we already have a hugetlb page mapped R/O that we will simply map writable and we are not dealing with COW/unsharing. Link: https://lkml.kernel.org/r/20220811103435.188481-3-david@redhat.com Fixes: b1f9e876862d ("mm/uffd: enable write protection for shmem & hugetlbfs") Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Hugh Dickins <hughd@google.com> Cc: Jamie Liu <jamieliu@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Peter Feiner <pfeiner@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: <stable@vger.kernel.org> [5.19] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08mm, hwpoison, hugetlb: support saving mechanism of raw error pagesNaoya Horiguchi
When handling memory error on a hugetlb page, the error handler tries to dissolve and turn it into 4kB pages. If it's successfully dissolved, PageHWPoison flag is moved to the raw error page, so that's all right. However, dissolve sometimes fails, then the error page is left as hwpoisoned hugepage. It's useful if we can retry to dissolve it to save healthy pages, but that's not possible now because the information about where the raw error pages is lost. Use the private field of a few tail pages to keep that information. The code path of shrinking hugepage pool uses this info to try delayed dissolve. In order to remember multiple errors in a hugepage, a singly-linked list originated from SUBPAGE_INDEX_HWPOISON-th tail page is constructed. Only simple operations (adding an entry or clearing all) are required and the list is assumed not to be very long, so this simple data structure should be enough. If we failed to save raw error info, the hwpoison hugepage has errors on unknown subpage, then this new saving mechanism does not work any more, so disable saving new raw error info and freeing hwpoison hugepages. Link: https://lkml.kernel.org/r/20220714042420.1847125-4-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entryNaoya Horiguchi
follow_pud_mask() does not support non-present pud entry now. As long as I tested on x86_64 server, follow_pud_mask() still simply returns no_page_table() for non-present_pud_entry() due to pud_bad(), so no severe user-visible effect should happen. But generally we should call follow_huge_pud() for non-present pud entry for 1GB hugetlb page. Update pud_huge() and follow_huge_pud() to handle non-present pud entries. The changes are similar to previous works for pud entries commit e66f17ff7177 ("mm/hugetlb: take page table lock in follow_huge_pmd()") and commit cbef8478bee5 ("mm/hugetlb: pmd_huge() returns true for non-present hugepage"). Link: https://lkml.kernel.org/r/20220714042420.1847125-3-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: David Hildenbrand <david@redhat.com> Cc: kernel test robot <lkp@intel.com> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08mm/hugetlb: check gigantic_page_runtime_supported() in ↵Naoya Horiguchi
return_unused_surplus_pages() Patch series "mm, hwpoison: enable 1GB hugepage support", v7. This patch (of 8): I found a weird state of 1GB hugepage pool, caused by the following procedure: - run a process reserving all free 1GB hugepages, - shrink free 1GB hugepage pool to zero (i.e. writing 0 to /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages), then - kill the reserving process. , then all the hugepages are free *and* surplus at the same time. $ cat /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages 3 $ cat /sys/kernel/mm/hugepages/hugepages-1048576kB/free_hugepages 3 $ cat /sys/kernel/mm/hugepages/hugepages-1048576kB/resv_hugepages 0 $ cat /sys/kernel/mm/hugepages/hugepages-1048576kB/surplus_hugepages 3 This state is resolved by reserving and allocating the pages then freeing them again, so this seems not to result in serious problem. But it's a little surprising (shrinking pool suddenly fails). This behavior is caused by hstate_is_gigantic() check in return_unused_surplus_pages(). This was introduced so long ago in 2008 by commit aa888a74977a ("hugetlb: support larger than MAX_ORDER"), and at that time the gigantic pages were not supposed to be allocated/freed at run-time. Now kernel can support runtime allocation/free, so let's check gigantic_page_runtime_supported() together. Link: https://lkml.kernel.org/r/20220714042420.1847125-1-naoya.horiguchi@linux.dev Link: https://lkml.kernel.org/r/20220714042420.1847125-2-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Muchun Song <songmuchun@bytedance.com> Cc: kernel test robot <lkp@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08mm: hugetlb_vmemmap: improve hugetlb_vmemmap code readabilityMuchun Song
There is a discussion about the name of hugetlb_vmemmap_alloc/free in thread [1]. The suggestion suggested by David is rename "alloc/free" to "optimize/restore" to make functionalities clearer to users, "optimize" means the function will optimize vmemmap pages, while "restore" means restoring its vmemmap pages discared before. This commit does this. Another discussion is the confusion RESERVE_VMEMMAP_NR isn't used explicitly for vmemmap_addr but implicitly for vmemmap_end in hugetlb_vmemmap_alloc/free. David suggested we can compute what hugetlb_vmemmap_init() does now at runtime. We do not need to worry for the overhead of computing at runtime since the calculation is simple enough and those functions are not in a hot path. This commit has the following improvements: 1) The function suffixed name ("optimize/restore") is more expressive. 2) The logic becomes less weird in hugetlb_vmemmap_optimize/restore(). 3) The hugetlb_vmemmap_init() does not need to be exported anymore. 4) A ->optimize_vmemmap_pages field in struct hstate is killed. 5) There is only one place where checks is_power_of_2(sizeof(struct page)) instead of two places. 6) Add more comments for hugetlb_vmemmap_optimize/restore(). 7) For external users, hugetlb_optimize_vmemmap_pages() is used for detecting if the HugeTLB's vmemmap pages is optimizable originally. In this commit, it is killed and we introduce a new helper hugetlb_vmemmap_optimizable() to replace it. The name is more expressive. Link: https://lore.kernel.org/all/20220404074652.68024-2-songmuchun@bytedance.com/ [1] Link: https://lkml.kernel.org/r/20220628092235.91270-7-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Will Deacon <will@kernel.org> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-05Merge tag 'mm-stable-2022-08-03' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Most of the MM queue. A few things are still pending. Liam's maple tree rework didn't make it. This has resulted in a few other minor patch series being held over for next time. Multi-gen LRU still isn't merged as we were waiting for mapletree to stabilize. The current plan is to merge MGLRU into -mm soon and to later reintroduce mapletree, with a view to hopefully getting both into 6.1-rc1. Summary: - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe Lin, Yang Shi, Anshuman Khandual and Mike Rapoport - Some kmemleak fixes from Patrick Wang and Waiman Long - DAMON updates from SeongJae Park - memcg debug/visibility work from Roman Gushchin - vmalloc speedup from Uladzislau Rezki - more folio conversion work from Matthew Wilcox - enhancements for coherent device memory mapping from Alex Sierra - addition of shared pages tracking and CoW support for fsdax, from Shiyang Ruan - hugetlb optimizations from Mike Kravetz - Mel Gorman has contributed some pagealloc changes to improve latency and realtime behaviour. - mprotect soft-dirty checking has been improved by Peter Xu - Many other singleton patches all over the place" [ XFS merge from hell as per Darrick Wong in https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ] * tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits) tools/testing/selftests/vm/hmm-tests.c: fix build mm: Kconfig: fix typo mm: memory-failure: convert to pr_fmt() mm: use is_zone_movable_page() helper hugetlbfs: fix inaccurate comment in hugetlbfs_statfs() hugetlbfs: cleanup some comments in inode.c hugetlbfs: remove unneeded header file hugetlbfs: remove unneeded hugetlbfs_ops forward declaration hugetlbfs: use helper macro SZ_1{K,M} mm: cleanup is_highmem() mm/hmm: add a test for cross device private faults selftests: add soft-dirty into run_vmtests.sh selftests: soft-dirty: add test for mprotect mm/mprotect: fix soft-dirty check in can_change_pte_writable() mm: memcontrol: fix potential oom_lock recursion deadlock mm/gup.c: fix formatting in check_and_migrate_movable_page() xfs: fail dax mount if reflink is enabled on a partition mm/memcontrol.c: remove the redundant updating of stats_flush_threshold userfaultfd: don't fail on unrecognized features hugetlb_cgroup: fix wrong hugetlb cgroup numa stat ...
2022-08-03Merge tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecacheLinus Torvalds
Pull folio updates from Matthew Wilcox: - Fix an accounting bug that made NR_FILE_DIRTY grow without limit when running xfstests - Convert more of mpage to use folios - Remove add_to_page_cache() and add_to_page_cache_locked() - Convert find_get_pages_range() to filemap_get_folios() - Improvements to the read_cache_page() family of functions - Remove a few unnecessary checks of PageError - Some straightforward filesystem conversions to use folios - Split PageMovable users out from address_space_operations into their own movable_operations - Convert aops->migratepage to aops->migrate_folio - Remove nobh support (Christoph Hellwig) * tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache: (78 commits) fs: remove the NULL get_block case in mpage_writepages fs: don't call ->writepage from __mpage_writepage fs: remove the nobh helpers jfs: stop using the nobh helper ext2: remove nobh support ntfs3: refactor ntfs_writepages mm/folio-compat: Remove migration compatibility functions fs: Remove aops->migratepage() secretmem: Convert to migrate_folio hugetlb: Convert to migrate_folio aio: Convert to migrate_folio f2fs: Convert to filemap_migrate_folio() ubifs: Convert to filemap_migrate_folio() btrfs: Convert btrfs_migratepage to migrate_folio mm/migrate: Add filemap_migrate_folio() mm/migrate: Convert migrate_page() to migrate_folio() nfs: Convert to migrate_folio btrfs: Convert btree_migratepage to migrate_folio mm/migrate: Convert expected_page_refs() to folio_expected_refs() mm/migrate: Convert buffer_migrate_page() to buffer_migrate_folio() ...
2022-07-18hugetlb: fix memoryleak in hugetlb_mcopy_atomic_pteMiaohe Lin
When alloc_huge_page fails, *pagep is set to NULL without put_page first. So the hugepage indicated by *pagep is leaked. Link: https://lkml.kernel.org/r/20220709092629.54291-1-linmiaohe@huawei.com Fixes: 8cc5fcbb5be8 ("mm, hugetlb: fix racy resv_huge_pages underflow on UFFDIO_COPY") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-18mm/hugetlb: separate path for hwpoison entry in copy_hugetlb_page_range()Naoya Horiguchi
Originally copy_hugetlb_page_range() handles migration entries and hwpoisoned entries in similar manner. But recently the related code path has more code for migration entries, and when is_writable_migration_entry() was converted to !is_readable_migration_entry(), hwpoison entries on source processes got to be unexpectedly updated (which is legitimate for migration entries, but not for hwpoison entries). This results in unexpected serious issues like kernel panic when forking processes with hwpoison entries in pmd. Separate the if branch into one for hwpoison entries and one for migration entries. Link: https://lkml.kernel.org/r/20220704013312.2415700-3-naoya.horiguchi@linux.dev Fixes: 6c287605fd56 ("mm: remember exclusively mapped anonymous pages with PG_anon_exclusive") Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: <stable@vger.kernel.org> [5.18] Cc: David Hildenbrand <david@redhat.com> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17mm, hugetlb: skip irrelevant nodes in show_free_areas()Gang Li
show_free_areas() allows to filter out node specific data which is irrelevant to the allocation request. But hugetlb_show_meminfo() still shows hugetlb on all nodes, which is redundant and unnecessary. Use show_mem_node_skip() to skip irrelevant nodes. And replace hugetlb_show_meminfo() with hugetlb_show_meminfo_node(nid). before-and-after sample output of OOM: before: ``` [ 214.362453] Node 1 active_anon:148kB inactive_anon:4050920kB active_file:112kB inactive_file:100kB [ 214.375429] Node 1 Normal free:45100kB boost:0kB min:45576kB low:56968kB high:68360kB reserved_hig [ 214.388334] lowmem_reserve[]: 0 0 0 0 0 [ 214.390251] Node 1 Normal: 423*4kB (UE) 320*8kB (UME) 187*16kB (UE) 117*32kB (UE) 57*64kB (UME) 20 [ 214.397626] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB [ 214.401518] Node 1 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB ``` after: ``` [ 145.069705] Node 1 active_anon:128kB inactive_anon:4049412kB active_file:56kB inactive_file:84kB u [ 145.110319] Node 1 Normal free:45424kB boost:0kB min:45576kB low:56968kB high:68360kB reserved_hig [ 145.152315] lowmem_reserve[]: 0 0 0 0 0 [ 145.155244] Node 1 Normal: 470*4kB (UME) 373*8kB (UME) 247*16kB (UME) 168*32kB (UE) 86*64kB (UME) [ 145.164119] Node 1 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB ``` Link: https://lkml.kernel.org/r/20220706034655.1834-1-ligang.bdlg@bytedance.com Signed-off-by: Gang Li <ligang.bdlg@bytedance.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17hugetlb: do not update address in huge_pmd_unshareMike Kravetz
As an optimization for loops sequentially processing hugetlb address ranges, huge_pmd_unshare would update a passed address if it unshared a pmd. Updating a loop control variable outside the loop like this is generally a bad idea. These loops are now using hugetlb_mask_last_page to optimize scanning when non-present ptes are discovered. The same can be done when huge_pmd_unshare returns 1 indicating a pmd was unshared. Remove address update from huge_pmd_unshare. Change the passed argument type and update all callers. In loops sequentially processing addresses use hugetlb_mask_last_page to update address if pmd is unshared. [sfr@canb.auug.org.au: fix an unused variable warning/error] Link: https://lkml.kernel.org/r/20220622171117.70850960@canb.auug.org.au Link: https://lkml.kernel.org/r/20220621235620.291305-4-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: James Houghton <jthoughton@google.com> Cc: kernel test robot <lkp@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rolf Eike Beer <eike-kernel@sf-tec.de> Cc: Will Deacon <will@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17hugetlb: skip to end of PT page mapping when pte not presentMike Kravetz
Patch series "hugetlb: speed up linear address scanning", v2. At unmap, fork and remap time hugetlb address ranges are linearly scanned. We can optimize these scans if the ranges are sparsely populated. Also, enable page table "Lazy copy" for hugetlb at fork. NOTE: Architectures not defining CONFIG_ARCH_WANT_GENERAL_HUGETLB need to add an arch specific version hugetlb_mask_last_page() to take advantage of sparse address scanning improvements. Baolin Wang added the routine for arm64. Other architectures which could be optimized are: ia64, mips, parisc, powerpc, s390, sh and sparc. This patch (of 4): HugeTLB address ranges are linearly scanned during fork, unmap and remap operations. If a non-present entry is encountered, the code currently continues to the next huge page aligned address. However, a non-present entry implies that the page table page for that entry is not present. Therefore, the linear scan can skip to the end of range mapped by the page table page. This can speed operations on large sparsely populated hugetlb mappings. Create a new routine hugetlb_mask_last_page() that will return an address mask. When the mask is ORed with an address, the result will be the address of the last huge page mapped by the associated page table page. Use this mask to update addresses in routines which linearly scan hugetlb address ranges when a non-present pte is encountered. hugetlb_mask_last_page is related to the implementation of huge_pte_offset as hugetlb_mask_last_page is called when huge_pte_offset returns NULL. This patch only provides a complete hugetlb_mask_last_page implementation when CONFIG_ARCH_WANT_GENERAL_HUGETLB is defined. Architectures which provide their own versions of huge_pte_offset can also provide their own version of hugetlb_mask_last_page. Link: https://lkml.kernel.org/r/20220621235620.291305-1-mike.kravetz@oracle.com Link: https://lkml.kernel.org/r/20220621235620.291305-2-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Reported-by: kernel test robot <lkp@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Xu <peterx@redhat.com> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Cc: James Houghton <jthoughton@google.com> Cc: Mina Almasry <almasrymina@google.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Rolf Eike Beer <eike-kernel@sf-tec.de> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17mm: rename is_pinnable_page() to is_longterm_pinnable_page()Alex Sierra
Patch series "Add MEMORY_DEVICE_COHERENT for coherent device memory mapping", v9. This patch series introduces MEMORY_DEVICE_COHERENT, a type of memory owned by a device that can be mapped into CPU page tables like MEMORY_DEVICE_GENERIC and can also be migrated like MEMORY_DEVICE_PRIVATE. This patch series is mostly self-contained except for a few places where it needs to update other subsystems to handle the new memory type. System stability and performance are not affected according to our ongoing testing, including xfstests. How it works: The system BIOS advertises the GPU device memory (aka VRAM) as SPM (special purpose memory) in the UEFI system address map. The amdgpu driver registers the memory with devmap as MEMORY_DEVICE_COHERENT using devm_memremap_pages. The initial user for this hardware page migration capability is the Frontier supercomputer project. This functionality is not AMD-specific. We expect other GPU vendors to find this functionality useful, and possibly other hardware types in the future. Our test nodes in the lab are similar to the Frontier configuration, with .5 TB of system memory plus 256 GB of device memory split across 4 GPUs, all in a single coherent address space. Page migration is expected to improve application efficiency significantly. We will report empirical results as they become available. Coherent device type pages at gup are now migrated back to system memory if they are being pinned long-term (FOLL_LONGTERM). The reason is, that long-term pinning would interfere with the device memory manager owning the device-coherent pages (e.g. evictions in TTM). These series incorporate Alistair Popple patches to do this migration from pin_user_pages() calls. hmm_gup_test has been added to hmm-test to test different get user pages calls. This series includes handling of device-managed anonymous pages returned by vm_normal_pages. Although they behave like normal pages for purposes of mapping in CPU page tables and for COW, they do not support LRU lists, NUMA migration or THP. We also introduced a FOLL_LRU flag that adds the same behaviour to follow_page and related APIs, to allow callers to specify that they expect to put pages on an LRU list. This patch (of 14): is_pinnable_page() and folio_is_pinnable() are renamed to is_longterm_pinnable_page() and folio_is_longterm_pinnable() respectively. These functions are used in the FOLL_LONGTERM flag context. Link: https://lkml.kernel.org/r/20220715150521.18165-1-alex.sierra@amd.com Link: https://lkml.kernel.org/r/20220715150521.18165-2-alex.sierra@amd.com Signed-off-by: Alex Sierra <alex.sierra@amd.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03mm: hugetlb: kill set_huge_swap_pte_at()Qi Zheng
Commit e5251fd43007 ("mm/hugetlb: introduce set_huge_swap_pte_at() helper") add set_huge_swap_pte_at() to handle swap entries on architectures that support hugepages consisting of contiguous ptes. And currently the set_huge_swap_pte_at() is only overridden by arm64. set_huge_swap_pte_at() provide a sz parameter to help determine the number of entries to be updated. But in fact, all hugetlb swap entries contain pfn information, so we can find the corresponding folio through the pfn recorded in the swap entry, then the folio_size() is the number of entries that need to be updated. And considering that users will easily cause bugs by ignoring the difference between set_huge_swap_pte_at() and set_huge_pte_at(). Let's handle swap entries in set_huge_pte_at() and remove the set_huge_swap_pte_at(), then we can call set_huge_pte_at() anywhere, which simplifies our coding. Link: https://lkml.kernel.org/r/20220626145717.53572-1-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03mm: hugetlb: remove minimum_order variableMuchun Song
commit 641844f5616d ("mm/hugetlb: introduce minimum hugepage order") fixed a static checker warning and introduced a global variable minimum_order to fix the warning. However, the local variable in dissolve_free_huge_pages() can be initialized to huge_page_order(&default_hstate) to fix the warning. So remove minimum_order to simplify the code. Link: https://lkml.kernel.org/r/20220616033846.96937-1-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03mm/hugetlb: remove unnecessary huge_ptep_set_access_flags() in ↵Baolin Wang
hugetlb_mcopy_atomic_pte() There is no need to update the hugetlb access flags after just setting the hugetlb page table entry by set_huge_pte_at(), since the page table entry value has no changes. Thus remove the unnecessary huge_ptep_set_access_flags() in hugetlb_mcopy_atomic_pte(). Link: https://lkml.kernel.org/r/f3e28b897b53a69967a8b98a6fdcda3be80c9229.1653616175.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03mm/migration: fix potential pte_unmap on an not mapped pteMiaohe Lin
__migration_entry_wait and migration_entry_wait_on_locked assume pte is always mapped from caller. But this is not the case when it's called from migration_entry_wait_huge and follow_huge_pmd. Add a hugetlbfs variant that calls hugetlb_migration_entry_wait(ptep == NULL) to fix this issue. Link: https://lkml.kernel.org/r/20220530113016.16663-5-linmiaohe@huawei.com Fixes: 30dad30922cc ("mm: migration: add migrate_entry_wait_huge()") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Christoph Lameter <cl@linux.com> Cc: David Howells <dhowells@redhat.com> Cc: Huang Ying <ying.huang@intel.com> Cc: kernel test robot <lkp@intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03mm/migration: return errno when isolate_huge_page failedMiaohe Lin
We might fail to isolate huge page due to e.g. the page is under migration which cleared HPageMigratable. We should return errno in this case rather than always return 1 which could confuse the user, i.e. the caller might think all of the memory is migrated while the hugetlb page is left behind. We make the prototype of isolate_huge_page consistent with isolate_lru_page as suggested by Huang Ying and rename isolate_huge_page to isolate_hugetlb as suggested by Muchun to improve the readability. Link: https://lkml.kernel.org/r/20220530113016.16663-4-linmiaohe@huawei.com Fixes: e8db67eb0ded ("mm: migrate: move_pages() supports thp migration") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Suggested-by: Huang Ying <ying.huang@intel.com> Reported-by: kernel test robot <lkp@intel.com> (build error) Cc: Alistair Popple <apopple@nvidia.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Christoph Lameter <cl@linux.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-29hugetlb: Convert huge_add_to_page_cache() to use a folioMatthew Wilcox (Oracle)
Remove the last caller of add_to_page_cache() Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com>
2022-06-27docs: rename Documentation/vm to Documentation/mmMike Rapoport
so it will be consistent with code mm directory and with Documentation/admin-guide/mm and won't be confused with virtual machines. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Suggested-by: Matthew Wilcox <willy@infradead.org> Tested-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Jonathan Corbet <corbet@lwn.net> Acked-by: Wu XiangCheng <bobwxc@email.cn>
2022-06-01delayacct: track delays from write-protect copyYang Yang
Delay accounting does not track the delay of write-protect copy. When tasks trigger many write-protect copys(include COW and unsharing of anonymous pages[1]), it may spend a amount of time waiting for them. To get the delay of tasks in write-protect copy, could help users to evaluate the impact of using KSM or fork() or GUP. Also update tools/accounting/getdelays.c: / # ./getdelays -dl -p 231 print delayacct stats ON listen forever PID 231 CPU count real total virtual total delay total delay average 6247 1859000000 2154070021 1674255063 0.268ms IO count delay total delay average 0 0 0ms SWAP count delay total delay average 0 0 0ms RECLAIM count delay total delay average 0 0 0ms THRASHING count delay total delay average 0 0 0ms COMPACT count delay total delay average 3 72758 0ms WPCOPY count delay total delay average 3635 271567604 0ms [1] commit 31cc5bc4af70("mm: support GUP-triggered unsharing of anonymous pages") Link: https://lkml.kernel.org/r/20220409014342.2505532-1-yang.yang29@zte.com.cn Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jiang Xuexin <jiang.xuexin@zte.com.cn> Reviewed-by: Ran Xiaokai <ran.xiaokai@zte.com.cn> Reviewed-by: wangyong <wang.yong12@zte.com.cn> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-27Merge tag 'mm-hotfixes-stable-2022-05-27' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull hotfixes from Andrew Morton: "Six hotfixes. The page_table_check one from Miaohe Lin is considered a minor thing so it isn't marked for -stable. The remainder address pre-5.19 issues and are cc:stable" * tag 'mm-hotfixes-stable-2022-05-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/page_table_check: fix accessing unmapped ptep kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add] mm/page_alloc: always attempt to allocate at least one page during bulk allocation hugetlb: fix huge_pmd_unshare address update zsmalloc: fix races between asynchronous zspage free and page migration Revert "mm/cma.c: remove redundant cma_mutex lock"
2022-05-27hugetlb: fix huge_pmd_unshare address updateMike Kravetz
The routine huge_pmd_unshare() is passed a pointer to an address associated with an area which may be unshared. If unshare is successful this address is updated to 'optimize' callers iterating over huge page addresses. For the optimization to work correctly, address should be updated to the last huge page in the unmapped/unshared area. However, in the common case where the passed address is PUD_SIZE aligned, the address is incorrectly updated to the address of the preceding huge page. That wastes CPU cycles as the unmapped/unshared range is scanned twice. Link: https://lkml.kernel.org/r/20220524205003.126184-1-mike.kravetz@oracle.com Fixes: 39dde65c9940 ("shared page table for hugetlb page") Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/hugetlb: handle uffd-wp during fork()Peter Xu
Firstly, we'll need to pass in dst_vma into copy_hugetlb_page_range() because for uffd-wp it's the dst vma that matters on deciding how we should treat uffd-wp protected ptes. We should recognize pte markers during fork and do the pte copy if needed. [lkp@intel.com: vma_needs_copy can be static] Link: https://lkml.kernel.org/r/Ylb0CGeFJlc4EzLk@7ec4ff11d4ae Link: https://lkml.kernel.org/r/20220405014918.14932-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/hugetlb: only drop uffd-wp special pte if requiredPeter Xu
As with shmem uffd-wp special ptes, only drop the uffd-wp special swap pte if unmapping an entire vma or synchronized such that faults can not race with the unmap operation. This requires passing zap_flags all the way to the lowest level hugetlb unmap routine: __unmap_hugepage_range. In general, unmap calls originated in hugetlbfs code will pass the ZAP_FLAG_DROP_MARKER flag as synchronization is in place to prevent faults. The exception is hole punch which will first unmap without any synchronization. Later when hole punch actually removes the page from the file, it will check to see if there was a subsequent fault and if so take the hugetlb fault mutex while unmapping again. This second unmap will pass in ZAP_FLAG_DROP_MARKER. The justification of "whether to apply ZAP_FLAG_DROP_MARKER flag when unmap a hugetlb range" is (IMHO): we should never reach a state when a page fault could errornously fault in a page-cache page that was wr-protected to be writable, even in an extremely short period. That could happen if e.g. we pass ZAP_FLAG_DROP_MARKER when hugetlbfs_punch_hole() calls hugetlb_vmdelete_list(), because if a page faults after that call and before remove_inode_hugepages() is executed, the page cache can be mapped writable again in the small racy window, that can cause unexpected data overwritten. [peterx@redhat.com: fix sparse warning] Link: https://lkml.kernel.org/r/Ylcdw8I1L5iAoWhb@xz-m1.local [akpm@linux-foundation.org: move zap_flags_t from mm.h to mm_types.h to fix build issues] Link: https://lkml.kernel.org/r/20220405014915.14873-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/hugetlb: allow uffd wr-protect none ptesPeter Xu
Teach hugetlbfs code to wr-protect none ptes just in case the page cache existed for that pte. Meanwhile we also need to be able to recognize a uffd-wp marker pte and remove it for uffd_wp_resolve. Since at it, introduce a variable "psize" to replace all references to the huge page size fetcher. Link: https://lkml.kernel.org/r/20220405014912.14815-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/hugetlb: handle pte markers in page faultsPeter Xu
Allow hugetlb code to handle pte markers just like none ptes. It's mostly there, we just need to make sure we don't assume hugetlb_no_page() only handles none pte, so when detecting pte change we should use pte_same() rather than pte_none(). We need to pass in the old_pte to do the comparison. Check the original pte to see whether it's a pte marker, if it is, we should recover uffd-wp bit on the new pte to be installed, so that the next write will be trapped by uffd. Link: https://lkml.kernel.org/r/20220405014909.14761-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/hugetlb: handle UFFDIO_WRITEPROTECTPeter Xu
This starts from passing cp_flags into hugetlb_change_protection() so hugetlb will be able to handle MM_CP_UFFD_WP[_RESOLVE] requests. huge_pte_clear_uffd_wp() is introduced to handle the case where the UFFDIO_WRITEPROTECT is requested upon migrating huge page entries. Link: https://lkml.kernel.org/r/20220405014906.14708-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/hugetlb: take care of UFFDIO_COPY_MODE_WPPeter Xu
Pass the wp_copy variable into hugetlb_mcopy_atomic_pte() thoughout the stack. Apply the UFFD_WP bit if UFFDIO_COPY_MODE_WP is with UFFDIO_COPY. Hugetlb pages are only managed by hugetlbfs, so we're safe even without setting dirty bit in the huge pte if the page is installed as read-only. However we'd better still keep the dirty bit set for a read-only UFFDIO_COPY pte (when UFFDIO_COPY_MODE_WP bit is set), not only to match what we do with shmem, but also because the page does contain dirty data that the kernel just copied from the userspace. Link: https://lkml.kernel.org/r/20220405014904.14643-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/hugetlb: hook page faults for uffd write protectionPeter Xu
Hook up hugetlbfs_fault() with the capability to handle userfaultfd-wp faults. We do this slightly earlier than hugetlb_cow() so that we can avoid taking some extra locks that we definitely don't need. Link: https://lkml.kernel.org/r/20220405014901.14590-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>