Re: [Xen-devel] [PATCH 00/16] x86: indirect call overhead reduction

2018-08-01 Thread Jan Beulich
>>> On 11.07.18 at 15:15, wrote: > While indirect calls have always been more expensive than direct ones, > their cost has further increased with the Spectre v2 mitigations. In a > number of cases we simply pointlessly use them in the first place. In > many other cases the indirection solely

Re: [Xen-devel] [PATCH 00/16] x86: indirect call overhead reduction

2018-07-16 Thread Jan Beulich
>>> On 13.07.18 at 19:15, wrote: > On 13/07/18 15:27, Jan Beulich wrote: > On 13.07.18 at 15:39, wrote: >>> On 13/07/18 14:27, Jan Beulich wrote: >>> On 13.07.18 at 15:00, wrote: > What would be the generic interface here? I saw it was based on > alternative for the plumbing.

Re: [Xen-devel] [PATCH 00/16] x86: indirect call overhead reduction

2018-07-13 Thread Julien Grall
Hi, On 13/07/18 14:27, Jan Beulich wrote: On 13.07.18 at 15:00, wrote: Hi Jan, On 13/07/18 09:10, Jan Beulich wrote: On 11.07.18 at 15:15, wrote: While indirect calls have always been more expensive than direct ones, their cost has further increased with the Spectre v2 mitigations. In a

Re: [Xen-devel] [PATCH 00/16] x86: indirect call overhead reduction

2018-07-13 Thread Jan Beulich
>>> On 13.07.18 at 15:00, wrote: > Hi Jan, > > On 13/07/18 09:10, Jan Beulich wrote: > On 11.07.18 at 15:15, wrote: >>> While indirect calls have always been more expensive than direct ones, >>> their cost has further increased with the Spectre v2 mitigations. In a >>> number of cases we

Re: [Xen-devel] [PATCH 00/16] x86: indirect call overhead reduction

2018-07-13 Thread Julien Grall
Hi Jan, On 13/07/18 09:10, Jan Beulich wrote: On 11.07.18 at 15:15, wrote: While indirect calls have always been more expensive than direct ones, their cost has further increased with the Spectre v2 mitigations. In a number of cases we simply pointlessly use them in the first place. In many

Re: [Xen-devel] [PATCH 00/16] x86: indirect call overhead reduction

2018-07-13 Thread Jan Beulich
>>> On 11.07.18 at 15:15, wrote: > While indirect calls have always been more expensive than direct ones, > their cost has further increased with the Spectre v2 mitigations. In a > number of cases we simply pointlessly use them in the first place. In > many other cases the indirection solely

[Xen-devel] [PATCH 00/16] x86: indirect call overhead reduction

2018-07-11 Thread Jan Beulich
While indirect calls have always been more expensive than direct ones, their cost has further increased with the Spectre v2 mitigations. In a number of cases we simply pointlessly use them in the first place. In many other cases the indirection solely exists to abstract from e.g. vendor specific