Le 21/08/2024 à 10:18, Qi Zheng a écrit : > In handle_pte_fault(), we may modify the vmf->pte after acquiring the > vmf->ptl, so convert it to using pte_offset_map_maywrite_nolock(). But > since we already do the pte_same() check, so there is no need to get > pmdval to do pmd_same() check, just pass NULL to pmdvalp parameter. > > Signed-off-by: Qi Zheng <zhengqi.a...@bytedance.com> > --- > mm/memory.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index 93c0c25433d02..d3378e98faf13 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -5504,9 +5504,14 @@ static vm_fault_t handle_pte_fault(struct vm_fault > *vmf) > * pmd by anon khugepaged, since that takes mmap_lock in write > * mode; but shmem or file collapse to THP could still morph > * it into a huge pmd: just retry later if so. > + * > + * Use the maywrite version to indicate that vmf->pte will be > + * modified, but since we will use pte_same() to detect the > + * change of the pte entry, there is no need to get pmdval. > */ > - vmf->pte = pte_offset_map_nolock(vmf->vma->vm_mm, vmf->pmd, > - vmf->address, &vmf->ptl); > + vmf->pte = pte_offset_map_maywrite_nolock(vmf->vma->vm_mm, > + vmf->pmd, > vmf->address, > + NULL, &vmf->ptl);
This might be the demonstration that the function name is becoming too long. Can you find shorter names ? > if (unlikely(!vmf->pte)) > return 0; > vmf->orig_pte = ptep_get_lockless(vmf->pte);
