Messages in this thread Patch in this message | | | Date | Wed, 13 Jun 2012 16:59:23 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH -V9 04/15] hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages |
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On Wed 13-06-12 15:57:23, Aneesh Kumar K.V wrote: > From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> > > Use a mmu_gather instead of a temporary linked list for accumulating > pages when we unmap a hugepage range
Sorry for coming up with the comment that late but you owe us an explanation _why_ you are doing this.
I assume that this fixes a real problem when we take i_mmap_mutex already up in unmap_mapping_range mutex_lock(&mapping->i_mmap_mutex); unmap_mapping_range_tree | unmap_mapping_range_list unmap_mapping_range_vma zap_page_range_single unmap_single_vma unmap_hugepage_range mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
And that this should have been marked for stable as well (I haven't checked when this has been introduced).
But then I do not see how this help when you still do this: [...] > diff --git a/mm/memory.c b/mm/memory.c > index 1b7dc66..545e18a 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -1326,8 +1326,11 @@ static void unmap_single_vma(struct mmu_gather *tlb, > * Since no pte has actually been setup, it is > * safe to do nothing in this case. > */ > - if (vma->vm_file) > - unmap_hugepage_range(vma, start, end, NULL); > + if (vma->vm_file) { > + mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex); > + __unmap_hugepage_range(tlb, vma, start, end, NULL); > + mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex); > + } > } else > unmap_page_range(tlb, vma, start, end, details); > }
-- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic
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