Messages in this thread | | | Date | Thu, 2 Jul 2015 00:41:54 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH 2/4] mremap: don't do mm_populate(new_addr) on failure |
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On 07/01, David Rientjes wrote: > > On Sat, 20 Jun 2015, Oleg Nesterov wrote: > > > move_vma() sets *locked even if move_page_tables() or ->mremap() > > fails, change sys_mremap() to check "ret & ~PAGE_MASK". > > > > I think we should simply remove the VM_LOCKED code in move_vma(), > > that is why this patch doesn't change move_vma(). But this needs > > more cleanups. > > > > Signed-off-by: Oleg Nesterov <oleg@redhat.com> > > --- > > mm/mremap.c | 4 +++- > > 1 files changed, 3 insertions(+), 1 deletions(-) > > > > diff --git a/mm/mremap.c b/mm/mremap.c > > index a6306bc..492721c 100644 > > --- a/mm/mremap.c > > +++ b/mm/mremap.c > > @@ -574,8 +574,10 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, > > ret = move_vma(vma, addr, old_len, new_len, new_addr, &locked); > > } > > out: > > - if (ret & ~PAGE_MASK) > > + if (ret & ~PAGE_MASK) { > > vm_unacct_memory(charged); > > + locked = 0; > > + } > > up_write(¤t->mm->mmap_sem); > > if (locked && new_len > old_len) > > mm_populate(new_addr + old_len, new_len - old_len); > > Acked-by: David Rientjes <rientjes@google.com>
Thanks! I am resending this series with your acks applies.
Plus another patche which was already acked but ignored anyway ;)
> Might be cleaner to rename this to "populate" in sys_mremap() and set it > to false in the previous old_len >= new_len conditional and remove the > check here for new_len > old_len.
Oh, this needs much more cleanups. Imo the whole VM_LOCKED logic in these paths is ugly and confusing. move_vma() shouldn't look at VM_LOCKED at all, mremap_to() should not duplicate the vma_to_resize/move_vma code, etc.
Oleg.
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