Re: [Xen-ia64-devel] One unstablity in fast syscall path

2006-06-19 Thread Tristan Gingold
Le Lundi 19 Juin 2006 15:35, Magenheimer, Dan (HP Labs Fort Collins) a écrit : On this point VTi may have a real advantage over paravirtualization. Could you explain further? Yes. The virtualization handler has the opcode in GR25. I don't know the amount of PAL code involved,

Re: [Xen-ia64-devel] One unstablity in fast syscall path

2006-06-14 Thread Tristan Gingold
Le Mardi 13 Juin 2006 22:11, Magenheimer, Dan (HP Labs Fort Collins) a écrit : After reading some Xen/ia64 source, I think we'd better not to use vpsr.ic for fast hypercall: it has some interractions with vpsr.ic flag! I'd vote for creating a new paravirtualized register: xen_break (or

Re: [Xen-ia64-devel] One unstablity in fast syscall path

2006-06-14 Thread Tristan Gingold
Le Mercredi 14 Juin 2006 05:02, Isaku Yamahata a écrit : On Tue, Jun 13, 2006 at 01:11:04PM -0700, Magenheimer, Dan (HP Labs Fort Collins) wrote: There are two purposes of paravirtualization: one is correctness and the other is performance. If fully virtualized vDSO works properly and

RE: [Xen-ia64-devel] One unstablity in fast syscall path

2006-06-14 Thread Magenheimer, Dan (HP Labs Fort Collins)
I have a question on priv_handle_op(). I changed the function so that xen/ia64 reflects itlb miss to a domain when xen/ia64 fails to read a bundle. Xen/ia64 reflected dtlb miss before my change. Is it correct to reflect dtlb miss? No this was just a hack that worked. It does need

Re: [Xen-ia64-devel] One unstablity in fast syscall path

2006-06-13 Thread Tristan Gingold
Le Mardi 13 Juin 2006 02:36, Tian, Kevin a écrit : Recently we kept seeing intermittent domU creation failure after creating VTI domain. After some debug, we found it caused by following changeset: changeset: 10238:b27139d8c1e1 user:[EMAIL PROTECTED] date:Sat Jun 03

Re: [Xen-ia64-devel] One unstablity in fast syscall path

2006-06-13 Thread Isaku Yamahata
On Mon, Jun 12, 2006 at 09:49:17PM -0600, Alex Williamson wrote: On Tue, 2006-06-13 at 08:36 +0800, Tian, Kevin wrote: That's the real problem, though we're not sure why this phenomenon is easier to be reproduced after creating VTI domain. Quick/easy solution can be to roll back above

RE: [Xen-ia64-devel] One unstablity in fast syscall path

2006-06-13 Thread Tian, Kevin
From: Isaku Yamahata [mailto:[EMAIL PROTECTED] Sent: 2006年6月13日 19:13 There are the following choices for right fix, I think. A. use hypercall instead of hyperprivop. B. introduce new flag for hyperprivop instread VPSR.ic as Tristan proposed. C. use one of itr to map vDSO. D. abondan vDSO

Re: [Xen-ia64-devel] One unstablity in fast syscall path

2006-06-13 Thread Isaku Yamahata
On Tue, Jun 13, 2006 at 01:11:04PM -0700, Magenheimer, Dan (HP Labs Fort Collins) wrote: There are two purposes of paravirtualization: one is correctness and the other is performance. If fully virtualized vDSO works properly and there's no impact on performance, it shouldn't be

Re: [Xen-ia64-devel] One unstablity in fast syscall path

2006-06-12 Thread Alex Williamson
On Tue, 2006-06-13 at 08:36 +0800, Tian, Kevin wrote: That's the real problem, though we're not sure why this phenomenon is easier to be reproduced after creating VTI domain. Quick/easy solution can be to roll back above changeset to ensure tree stability first, and then community needs to