Messages in this thread | | | Subject | Re: [PATCH v4] mm: get rid of odd jump labels in find_mergeable_anon_vma() | From | David Hildenbrand <> | Date | Mon, 18 Nov 2019 14:48:35 +0100 |
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On 18.11.19 13:24, linmiaohe wrote: > From: Miaohe Lin <linmiaohe@huawei.com> > > The jump labels try_prev and none are not really needed > in find_mergeable_anon_vma(), eliminate them to improve > readability. > > Reviewed-by: David Hildenbrand <david@redhat.com> > Reviewed-by: John Hubbard <jhubbard@nvidia.com> > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > --- > -v2: > Fix commit descriptions and further simplify the code > as suggested by David Hildenbrand and John Hubbard. > -v3: > Rewrite patch version info. Don't show this in commit log. > -v4: > Get rid of var near completely as well. > --- > mm/mmap.c | 36 ++++++++++++++++-------------------- > 1 file changed, 16 insertions(+), 20 deletions(-) > > diff --git a/mm/mmap.c b/mm/mmap.c > index 91d5e097a4ed..4d93bda30eac 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -1273,26 +1273,22 @@ static struct anon_vma *reusable_anon_vma(struct vm_area_struct *old, struct vm_ > */ > struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *vma) > { > - struct anon_vma *anon_vma; > - struct vm_area_struct *near; > - > - near = vma->vm_next; > - if (!near) > - goto try_prev; > - > - anon_vma = reusable_anon_vma(near, vma, near); > - if (anon_vma) > - return anon_vma; > -try_prev: > - near = vma->vm_prev; > - if (!near) > - goto none; > - > - anon_vma = reusable_anon_vma(near, near, vma); > - if (anon_vma) > - return anon_vma; > -none: > + struct anon_vma *anon_vma = NULL; > + > + /* Try next first. */ > + if (vma->vm_next) { > + anon_vma = reusable_anon_vma(vma->vm_next, vma, vma->vm_next); > + if (anon_vma) > + return anon_vma; > + } > + > + /* Try prev next. */ > + if (vma->vm_prev) > + anon_vma = reusable_anon_vma(vma->vm_prev, vma->vm_prev, vma); > + > /* > + * We might reach here with anon_vma == NULL if we can't find > + * any reusable anon_vma. > * There's no absolute need to look only at touching neighbours: > * we could search further afield for "compatible" anon_vmas. > * But it would probably just be a waste of time searching, > @@ -1300,7 +1296,7 @@ struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *vma) > * We're trying to allow mprotect remerging later on, > * not trying to minimize memory used for anon_vmas. > */ > - return NULL; > + return anon_vma; > } > > /* >
Looks much better, thanks!
Reviewed-by: David Hildenbrand <david@redhat.com>
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Thanks,
David / dhildenb
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