Re: [PATCH 3/3] x86/xen: Move paravirt IOPL switching to slow the path

2017-06-14 Thread Andy Lutomirski
On Wed, Jun 14, 2017 at 11:25 AM, Brian Gerst wrote: > On Wed, Jun 14, 2017 at 2:02 PM, Andrew Cooper > wrote: >> On 14/06/17 18:40, Andy Lutomirski wrote: >>> On Wed, Jun 14, 2017 at 5:40 AM, Brian Gerst wrote: Since tasks using IOPL are very rare, move the switching code to the slow

Re: [PATCH 3/3] x86/xen: Move paravirt IOPL switching to slow the path

2017-06-14 Thread Brian Gerst
On Wed, Jun 14, 2017 at 2:02 PM, Andrew Cooper wrote: > On 14/06/17 18:40, Andy Lutomirski wrote: >> On Wed, Jun 14, 2017 at 5:40 AM, Brian Gerst wrote: >>> Since tasks using IOPL are very rare, move the switching code to the slow >>> path for lower impact on normal tasks. >> I think that Andrew

Re: [PATCH 3/3] x86/xen: Move paravirt IOPL switching to slow the path

2017-06-14 Thread Andrew Cooper
On 14/06/17 18:40, Andy Lutomirski wrote: > On Wed, Jun 14, 2017 at 5:40 AM, Brian Gerst wrote: >> Since tasks using IOPL are very rare, move the switching code to the slow >> path for lower impact on normal tasks. > I think that Andrew Cooper added a vmassist that we could opt in to > that makes

Re: [PATCH 3/3] x86/xen: Move paravirt IOPL switching to slow the path

2017-06-14 Thread Andy Lutomirski
On Wed, Jun 14, 2017 at 5:40 AM, Brian Gerst wrote: > Since tasks using IOPL are very rare, move the switching code to the slow > path for lower impact on normal tasks. I think that Andrew Cooper added a vmassist that we could opt in to that makes Xen PV IOPL switching work more or less just like

Re: [PATCH 3/3] x86/xen: Move paravirt IOPL switching to slow the path

2017-06-14 Thread Juergen Gross
On 14/06/17 19:29, Brian Gerst wrote: > On Wed, Jun 14, 2017 at 9:14 AM, Juergen Gross wrote: >> On 14/06/17 14:40, Brian Gerst wrote: >>> Since tasks using IOPL are very rare, move the switching code to the slow >>> path for lower impact on normal tasks. >>> >>> Signed-off-by: Brian Gerst >>> --

Re: [PATCH 3/3] x86/xen: Move paravirt IOPL switching to slow the path

2017-06-14 Thread Brian Gerst
On Wed, Jun 14, 2017 at 9:14 AM, Juergen Gross wrote: > On 14/06/17 14:40, Brian Gerst wrote: >> Since tasks using IOPL are very rare, move the switching code to the slow >> path for lower impact on normal tasks. >> >> Signed-off-by: Brian Gerst >> --- >> arch/x86/include/asm/paravirt.h |

Re: [PATCH 3/3] x86/xen: Move paravirt IOPL switching to slow the path

2017-06-14 Thread Juergen Gross
On 14/06/17 14:40, Brian Gerst wrote: > Since tasks using IOPL are very rare, move the switching code to the slow > path for lower impact on normal tasks. > > Signed-off-by: Brian Gerst > --- > arch/x86/include/asm/paravirt.h | 6 ++ > arch/x86/include/asm/processor.h | 1 + > a

[PATCH 3/3] x86/xen: Move paravirt IOPL switching to slow the path

2017-06-14 Thread Brian Gerst
Since tasks using IOPL are very rare, move the switching code to the slow path for lower impact on normal tasks. Signed-off-by: Brian Gerst --- arch/x86/include/asm/paravirt.h | 6 ++ arch/x86/include/asm/processor.h | 1 + arch/x86/include/asm/thread_info.h| 5 - arch/