The patch titled Subject: kernfs: drop shared NUMA mempolicy hooks has been added to the -mm mm-unstable branch. Its filename is kernfs-drop-shared-numa-mempolicy-hooks.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kernfs-drop-shared-numa-mempolicy-hooks.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Hugh Dickins <hughd@xxxxxxxxxx> Subject: kernfs: drop shared NUMA mempolicy hooks Date: Tue, 3 Oct 2023 02:16:29 -0700 (PDT) It seems strange that kernfs should be an outlier with a set_policy and get_policy in its kernfs_vm_ops. Ah, it dates back to v2.6.30's commit 095160aee954 ("sysfs: fix some bin_vm_ops errors"), when I had crashed on powerpc's pci_mmap_legacy_page_range() fallback to shmem_zero_setup(). Well, that was commendably thorough, to give sysfs-bin a set_policy and get_policy, just to avoid the way it was coded resulting in EINVAL from mmap when CONFIG_NUMA; but somehow feels a bit over-the-top to me now. It's easier to say that nobody should expect to manage a shmem object's shared NUMA mempolicy via some kernfs backdoor to that object: delete that code (and there's no longer an EINVAL from mmap in the NUMA case). This then leaves set_policy/get_policy as implemented only by shmem - though importantly also by SysV SHM, which has to interface with shmem which implements them, and with SHM_HUGETLB which does not. Link: https://lkml.kernel.org/r/302164-a760-4a9e-879b-6870c9b4013@xxxxxxxxxx Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: "Huang, Ying" <ying.huang@xxxxxxxxx> Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Nhat Pham <nphamcs@xxxxxxxxx> Cc: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx> Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx> Cc: Tejun heo <tj@xxxxxxxxxx> Cc: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx> Cc: Yang Shi <shy828301@xxxxxxxxx> Cc: Yosry Ahmed <yosryahmed@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/kernfs/file.c | 49 --------------------------------------------- 1 file changed, 49 deletions(-) --- a/fs/kernfs/file.c~kernfs-drop-shared-numa-mempolicy-hooks +++ a/fs/kernfs/file.c @@ -429,60 +429,11 @@ static int kernfs_vma_access(struct vm_a return ret; } -#ifdef CONFIG_NUMA -static int kernfs_vma_set_policy(struct vm_area_struct *vma, - struct mempolicy *new) -{ - struct file *file = vma->vm_file; - struct kernfs_open_file *of = kernfs_of(file); - int ret; - - if (!of->vm_ops) - return 0; - - if (!kernfs_get_active(of->kn)) - return -EINVAL; - - ret = 0; - if (of->vm_ops->set_policy) - ret = of->vm_ops->set_policy(vma, new); - - kernfs_put_active(of->kn); - return ret; -} - -static struct mempolicy *kernfs_vma_get_policy(struct vm_area_struct *vma, - unsigned long addr) -{ - struct file *file = vma->vm_file; - struct kernfs_open_file *of = kernfs_of(file); - struct mempolicy *pol; - - if (!of->vm_ops) - return vma->vm_policy; - - if (!kernfs_get_active(of->kn)) - return vma->vm_policy; - - pol = vma->vm_policy; - if (of->vm_ops->get_policy) - pol = of->vm_ops->get_policy(vma, addr); - - kernfs_put_active(of->kn); - return pol; -} - -#endif - static const struct vm_operations_struct kernfs_vm_ops = { .open = kernfs_vma_open, .fault = kernfs_vma_fault, .page_mkwrite = kernfs_vma_page_mkwrite, .access = kernfs_vma_access, -#ifdef CONFIG_NUMA - .set_policy = kernfs_vma_set_policy, - .get_policy = kernfs_vma_get_policy, -#endif }; static int kernfs_fop_mmap(struct file *file, struct vm_area_struct *vma) _ Patches currently in -mm which might be from hughd@xxxxxxxxxx are hugetlbfs-drop-shared-numa-mempolicy-pretence.patch kernfs-drop-shared-numa-mempolicy-hooks.patch mempolicy-fix-migrate_pages2-syscall-return-nr_failed.patch mempolicy-trivia-delete-those-ancient-pr_debugs.patch mempolicy-trivia-slightly-more-consistent-naming.patch mempolicy-trivia-use-pgoff_t-in-shared-mempolicy-tree.patch mempolicy-mpol_shared_policy_init-without-pseudo-vma.patch mempolicy-remove-confusing-mpol_mf_lazy-dead-code.patch mm-add-page_rmappable_folio-wrapper.patch mempolicy-alloc_pages_mpol-for-numa-policy-without-vma.patch mempolicy-mmap_lock-is-not-needed-while-migrating-folios.patch mempolicy-migration-attempt-to-match-interleave-nodes.patch