Re: Suggestions for TCG performance improvements

2021-12-06 Thread Alex Bennée
Vasilev Oleg writes: > On 12/3/2021 8:32 PM, Alex Bennée wrote: >> Vasilev Oleg writes: >> >>> On 12/2/2021 7:02 PM, Alex Bennée wrote: >>> Vasilev Oleg writes: > ...skipped... I did ponder a debug mode which would keep the last N tables dropped by tlb_mmu_resize_locked and the

Re: Suggestions for TCG performance improvements

2021-12-06 Thread Vasilev Oleg via
On 12/3/2021 8:32 PM, Alex Bennée wrote: > Vasilev Oleg writes: > >> On 12/2/2021 7:02 PM, Alex Bennée wrote: >> >>> Vasilev Oleg writes: ...skipped... >>> I did ponder a debug mode which would keep the last N tables dropped by >>> tlb_mmu_resize_locked and then measure the differences in the ent

Re: Suggestions for TCG performance improvements

2021-12-03 Thread Alex Bennée
Vasilev Oleg writes: > On 12/2/2021 7:02 PM, Alex Bennée wrote: > >> Vasilev Oleg writes: >> >>> I've discovered some MMU-related suggestions in the 2018 letter[2], and >>> those seem to be still not implemented (flush still uses memset[3]). >>> Do you think we should go forward with implement

Re: Suggestions for TCG performance improvements

2021-12-03 Thread Vasilev Oleg via
On 12/2/2021 7:02 PM, Alex Bennée wrote: > Vasilev Oleg writes: > >> I've discovered some MMU-related suggestions in the 2018 letter[2], and >> those seem to be still not implemented (flush still uses memset[3]). >> Do you think we should go forward with implementing those? > I doubt you can do b

Re: Suggestions for TCG performance improvements

2021-12-02 Thread Richard Henderson
On 12/2/21 9:21 PM, Emilio Cota wrote: On Thu, Dec 2, 2021 at 4:47 AM Vasilev Oleg wrote: The mentioned paper[4] also describes other possible improvements. Some of those are already implemented (such as victim TLB and dynamic size for TLB), but others are not (e.g. TLB lookup uninlining and se

Re: Suggestions for TCG performance improvements

2021-12-02 Thread Emilio Cota
On Thu, Dec 2, 2021 at 4:47 AM Vasilev Oleg wrote: > The mentioned paper[4] also describes other possible improvements. > Some of those are already implemented (such as victim TLB and dynamic > size for TLB), but others are not (e.g. TLB lookup uninlining and > set-associative TLB layer). Do you t

Re: Suggestions for TCG performance improvements

2021-12-02 Thread Alex Bennée
Vasilev Oleg writes: > Hi everyone, > > I've recently been tasked with improving QEMU performance and would like > to discuss several possible optimizations which we could implement and > later upstream. Excellent - it's always good to see others that want to improve our emulation performance