Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

On Wed, Jun 07, 2017 at 18:45:10 +0300, Lluís Vilanova wrote: > If there is such renewed interest, I will carve a bit more time to bring the > patches up to date and send the instrumentation ones for further discussion. I'm very interested and have time to spend on it -- I'm working on a

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

On 07/06/2017 17:52, Lluís Vilanova wrote: > Paolo Bonzini writes: > >> On 07/06/2017 14:07, Peter Maydell wrote: My understanding was that adding a public instrumentation interface would add too much code maintenance overhead for a feature that is not in QEMU's core

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

On 7 June 2017 at 16:45, Lluís Vilanova wrote: > This speed comes at the cost of exposing TCG operations to the instrumentation > library (i.e., the library can inject TCG code; AFAIR, calling out into a > function in the instrumentation library is slower than PIN). Mmm,

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

Lluís Vilanova writes: > Paolo Bonzini writes: > >> On 07/06/2017 14:07, Peter Maydell wrote: My understanding was that adding a public instrumentation interface would add too much code maintenance overhead for a feature that is not in QEMU's core

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

Paolo Bonzini writes: > On 07/06/2017 14:07, Peter Maydell wrote: >>> My understanding was that adding a public instrumentation interface would >>> add >>> too much code maintenance overhead for a feature that is not in QEMU's core >>> target. >> Well, it depends what you define as our core

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

Peter Maydell writes: > On 7 June 2017 at 12:12, Lluís Vilanova wrote: >> My understanding was that adding a public instrumentation interface would add >> too much code maintenance overhead for a feature that is not in QEMU's core >> target. > Well, it depends what you

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

On 07/06/2017 14:07, Peter Maydell wrote: >> My understanding was that adding a public instrumentation interface would add >> too much code maintenance overhead for a feature that is not in QEMU's core >> target. > Well, it depends what you define as our core target :-) > I think we get quite a

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

On 7 June 2017 at 12:12, Lluís Vilanova wrote: > My understanding was that adding a public instrumentation interface would add > too much code maintenance overhead for a feature that is not in QEMU's core > target. Well, it depends what you define as our core target :-) I

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

Emilio G Cota writes: > - Instrumentation. I think QEMU should have a good interface to enable > dynamic binary instrumentation. This has many uses and in fact there > are quite a few forks of QEMU doing this. > I think Lluís Vilanova's work [1] is a good start to eventually get >

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

Emilio G. Cota writes: > On Sat, Mar 25, 2017 at 12:52:35 -0400, Pranith Kumar wrote: > (snip) >> * Implement an LRU translation block code cache. >> >> In the current TCG design, when the translation cache fills up, we flush >> all >> the translated blocks (TBs) to free up

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

On Sat, Mar 25, 2017 at 12:52:35 -0400, Pranith Kumar wrote: (snip) > * Implement an LRU translation block code cache. > > In the current TCG design, when the translation cache fills up, we flush all > the translated blocks (TBs) to free up space. We can improve this situation > by not

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

On Mon, Mar 27, 2017 at 11:09:23PM -0400, Pranith Kumar wrote: > On Mon, Mar 27, 2017 at 11:03 PM, Pranith Kumar wrote: > > > > > If you think the project makes sense, I will add it to the GSoC wiki > > so that others can also apply for it. Please let me know if you are >

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

On Mon, Mar 27, 2017 at 11:03 PM, Pranith Kumar wrote: > > If you think the project makes sense, I will add it to the GSoC wiki > so that others can also apply for it. Please let me know if you are > interested in mentoring it along with Alex. > One other thing is if you

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

Hi Paolo, On Mon, Mar 27, 2017 at 7:32 AM, Paolo Bonzini wrote: > > > On 25/03/2017 17:52, Pranith Kumar wrote: >> * Implement an LRU translation block code cache. >> >> In the current TCG design, when the translation cache fills up, we flush >> all >> the translated

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

Hi Richard, Thanks for the feedback. Please find some comments inline. On Mon, Mar 27, 2017 at 6:57 AM, Richard Henderson wrote: > > 128MB is really quite large. I doubt doubling the cache size will really > help that much. That said, it's really quite trivial to make this

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

Hi Stefan, On Mon, Mar 27, 2017 at 11:54 AM, Stefan Hajnoczi wrote: > On Sat, Mar 25, 2017 at 12:52:35PM -0400, Pranith Kumar wrote: >> Alex Bennée, who mentored me last year, has agreed to mentor me again this >> time if the proposal is accepted. > > Thanks, the project idea

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

On Sat, Mar 25, 2017 at 12:52:35PM -0400, Pranith Kumar wrote: > Alex Bennée, who mentored me last year, has agreed to mentor me again this > time if the proposal is accepted. Thanks, the project idea looks good for GSoC. I've talked to Alex about adding it to the wiki page. The "How to propose

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

Richard Henderson writes: > On 03/26/2017 02:52 AM, Pranith Kumar wrote: >> Hello, >> > >> Please let me know if you have any comments or suggestions. Also please let >> me >> know if there are other enhancements that are easily implementable to >> increase >> TCG

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

On 25/03/2017 17:52, Pranith Kumar wrote: > * Implement an LRU translation block code cache. > > In the current TCG design, when the translation cache fills up, we flush all > the translated blocks (TBs) to free up space. We can improve this situation > by not flushing the TBs that were

Re: [Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

On 03/26/2017 02:52 AM, Pranith Kumar wrote: Hello, With MTTCG code now merged in mainline, I tried to see if we are able to run x86 SMP guests on ARM64 hosts. For this I tried running a windows XP guest on a dragonboard 410c which has 1GB RAM. Since x86 has a strong memory model whereas ARM64

[Qemu-devel] GSoC 2017 Proposal: TCG performance enhancements

Hello, With MTTCG code now merged in mainline, I tried to see if we are able to run x86 SMP guests on ARM64 hosts. For this I tried running a windows XP guest on a dragonboard 410c which has 1GB RAM. Since x86 has a strong memory model whereas ARM64 is a weak memory model, I added a patch to