Re: [PATCH v3 29/40] mm: drop some redundant checks around hugetlb VMAs
From: "Zi Yan" <ziy@nvidia.com>
Date: 2026-09-29 02:36:59
Also in:
bpf, fuse-devel, kvm, kvm-riscv, kvmarm, linux-arch, linux-doc, linux-fsdevel, linux-mm, linux-perf-users, linux-rdma, linux-s390, linux-scsi, linux-sound, linux-trace-kernel, linux-usb, linuxppc-dev, lkml, selinux, sparclinux
On Thu Sep 17, 2026 at 12:22 PM EDT, Lorenzo Stoakes (ARM) wrote:
Adjust code which inadvertently perform redundant checks on hugetlb VMAs and clean them up: * hugetlb VMAs have VMA_DONTEXPAND_BIT set so a VMA_SPECIAL_FLAGS check suffices. (migrate_vma_setup() regains an explicit hugetlb test later in the series, once VMA_SPECIAL_FLAGS is removed.) * hugetlb VMAs unconditionally set vma->vm_ops, so they are never anonymous. * hugetlb VMAs do not set VMA_PFNMAP_BIT so checking for this is redundant. While we're here also drop a VM_BUG_ON() which the simplified check above makes unreachable, and use the new VMA flag API. No functional change intended. Acked-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> --- arch/arm64/kvm/mmu.c | 4 +--- drivers/gpu/drm/drm_gpusvm.c | 3 +-- mm/migrate_device.c | 4 ++-- 3 files changed, 4 insertions(+), 7 deletions(-)
Makes sense. Reviewed-by: Zi Yan <ziy@nvidia.com> -- Best Regards, Yan, Zi