Messages in this thread | | | Date | Tue, 01 Sep 2015 13:54:26 +0300 | From | Boaz Harrosh <> | Subject | Re: [PATCH] mm, dax: VMA with vm_ops->pfn_mkwrite wants to be write-notified |
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On 09/01/2015 01:22 PM, Kirill A. Shutemov wrote: > For VM_PFNMAP and VM_MIXEDMAP we use vm_ops->pfn_mkwrite instead of > vm_ops->page_mkwrite to notify abort write access. This means we want > vma->vm_page_prot to be write-protected if the VMA provides this vm_ops. >
Hi Kirill
I will test with this right away and ACK on this.
Hmm so are you saying we might be missing some buffer modifications right now.
What would be a theoretical scenario that will cause these missed events? I would like to put a test in our test rigs that should fail today and this patch fixes.
[In our system every modified pmem block is also RDMAed to a remote pmem for HA, a missed modification will make the two copies unsynced]
Thanks for catching this Boaz
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Cc: Yigal Korman <yigal@plexistor.com> > Cc: Boaz Harrosh <boaz@plexistor.com> > Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> > Cc: Jan Kara <jack@suse.cz> > Cc: Dave Chinner <david@fromorbit.com> > --- > mm/mmap.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/mmap.c b/mm/mmap.c > index df6d5f07035b..3f78bceefe5a 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -1498,7 +1498,8 @@ int vma_wants_writenotify(struct vm_area_struct *vma) > return 0; > > /* The backer wishes to know when pages are first written to? */ > - if (vma->vm_ops && vma->vm_ops->page_mkwrite) > + if (vma->vm_ops && > + (vma->vm_ops->page_mkwrite || vma->vm_ops->pfn_mkwrite)) > return 1; > > /* The open routine did something to the protections that pgprot_modify >
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