| From | Michel Lespinasse <> | Subject | [RFC PATCH 18/37] mm: enable speculative fault handling in do_numa_page() | Date | Tue, 6 Apr 2021 18:44:43 -0700 |
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Change handle_pte_fault() to allow speculative fault execution to proceed through do_numa_page().
do_swap_page() does not implement speculative execution yet, so it needs to abort with VM_FAULT_RETRY in that case.
Signed-off-by: Michel Lespinasse <michel@lespinasse.org> --- mm/memory.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c index 78cc36749754..eea72bd78d06 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3346,6 +3346,11 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) vm_fault_t ret = 0; void *shadow = NULL; + if (vmf->flags & FAULT_FLAG_SPECULATIVE) { + pte_unmap(vmf->pte); + return VM_FAULT_RETRY; + } + if (!pte_unmap_same(vma->vm_mm, vmf->pmd, vmf->pte, vmf->orig_pte)) goto out; @@ -4342,17 +4347,17 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf) return do_fault(vmf); } - if (vmf->flags & FAULT_FLAG_SPECULATIVE) { - pte_unmap(vmf->pte); - return VM_FAULT_RETRY; - } - if (!pte_present(vmf->orig_pte)) return do_swap_page(vmf); if (pte_protnone(vmf->orig_pte) && vma_is_accessible(vmf->vma)) return do_numa_page(vmf); + if (vmf->flags & FAULT_FLAG_SPECULATIVE) { + pte_unmap(vmf->pte); + return VM_FAULT_RETRY; + } + vmf->ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd); spin_lock(vmf->ptl); entry = vmf->orig_pte; -- 2.20.1
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