Hi all,
when a stubdom is destroyed, fs-backend does not correctly unmap all the
pages mapped for the shared ring.
This causes some pages not to be properly freed by xen, hence after a
cycle of 50 save\restore we don''t have enough spare memory to start 2
VMs any more.
This patch fixes the issue properly unmapping all the pages needed by
the shared ring.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
diff -r 633e08774dab tools/fs-back/fs-backend.c
--- a/tools/fs-back/fs-backend.c Thu Mar 19 14:01:56 2009 +0000
+++ b/tools/fs-back/fs-backend.c Thu Mar 19 16:33:34 2009 +0000
@@ -161,7 +161,7 @@
while (!xenbus_frontend_state_changed(mount, STATE_CLOSING));
xenbus_write_backend_state(mount, STATE_CLOSED);
- xc_gnttab_munmap(mount->gnth, mount->ring.sring, 1);
+ xc_gnttab_munmap(mount->gnth, mount->ring.sring,
mount->shared_ring_size);
xc_gnttab_close(mount->gnth);
xc_evtchn_unbind(mount->evth, mount->local_evtchn);
xc_evtchn_close(mount->evth);
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On Thu, Mar 19, 2009 at 12:58 PM, Stefano Stabellini <stefano.stabellini@eu.citrix.com> wrote:> Hi all, > when a stubdom is destroyed, fs-backend does not correctly unmap all the > pages mapped for the shared ring. > This causes some pages not to be properly freed by xen, hence after a > cycle of 50 save\restore we don''t have enough spare memory to start 2 > VMs any more. > This patch fixes the issue properly unmapping all the pages needed by > the shared ring. >I can confirm that fs-backend is more stable. I have performed hundreds of save/restore cycles without issue. Keith Coleman _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Stefano Stabellini
2009-Mar-23 10:48 UTC
Re: [Xen-devel] [PATCH] fs-backend: fix gnttab unmap
Keith Coleman wrote:> On Thu, Mar 19, 2009 at 12:58 PM, Stefano Stabellini > <stefano.stabellini@eu.citrix.com> wrote: >> Hi all, >> when a stubdom is destroyed, fs-backend does not correctly unmap all the >> pages mapped for the shared ring. >> This causes some pages not to be properly freed by xen, hence after a >> cycle of 50 save\restore we don''t have enough spare memory to start 2 >> VMs any more. >> This patch fixes the issue properly unmapping all the pages needed by >> the shared ring. >> > > I can confirm that fs-backend is more stable. I have performed > hundreds of save/restore cycles without issue. >good, thanks again for testing. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel