Messages in this thread | | | Date | Thu, 16 Oct 2014 13:37:19 -0700 | From | Dmitry Torokhov <> | Subject | Re: [Xen-devel] [PATCH] Input: xen-kbdfront - free grant table entry in xenkbd_disconnect_backend |
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On Thu, Oct 16, 2014 at 05:01:09PM +0100, David Vrabel wrote: > On 16/10/14 02:46, hansechang@gmail.com wrote: > > From: Chang Huaixin <huaixin.chx@alibaba-inc.com> > > > > xenkbd_disconnect_backend doesn't free grant table entry. > > This bug affects live migration. > > > > xenkbd_disconnect_backend uses gnttab_end_foreign_access_ref > > to handle grant table entry which doesn't really free an entry. > > > > Thus every time we do xenkbd_resume, grant table entry increses > > by one. As an grant table entry occupies 8 bytes, an grant table > > page has at most 512 entries. Every 512 times we do xenkdb_resume, > > grant table pages increses by one. > > > > After around 3500 times of live migration, grant table pages > > will increase by 7, causing too many pages to populate and hitting > > max_pages limit when assigning pages.Thus assign_pages will fail, > > so will live migration. > > Acked-by: David Vrabel <david.vrabel@citrix.com> > > This need to be send to the input subsystem maintainers.
Applied, thank you.
-- Dmitry
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