Re: [PATCH 0/7] Embedded PPC misc clean up and optimisation

[Daniel Henrique Barboza]

Queued in gitlab.com/danielhb/qemu/tree/ppc-next. Thanks,


Daniel

On 5/30/23 10:28, BALATON Zoltan wrote:
> Hello,
>
> This series improves embedded PPC TLB emulation a bit and contains
> some misc clean up I've found along the way. Before this patch
> ppcemb_tlb_check() shows up in a memory access intensive profile
> (running RageMem speed test in AmigaOS on sam460ex) at 11.91%
> children, 10.77% self. After this series it does not show up at all.
> This is not the biggest bottleneck, that is calling tlb_flush() from
> helper_440_tlbwe() excessively but this was simpler to clean up and
> still makes a small improvement.
>
> RageMem results on master:
> ---> RAM <---
> READ32:  593 MB/Sec
> READ64:  616 MB/Sec
> WRITE32: 589 MB/Sec
> WRITE64: 621 MB/Sec
> WRITE: 518 MB/Sec (Tricky)
>
> ---> VIDEO BUS <---
> READ:  588 MB/Sec
> WRITE: 571 MB/Sec
>
> with this series:
> ---> RAM <---
> READ32:  674 MB/Sec
> READ64:  707 MB/Sec
> WRITE32: 665 MB/Sec
> WRITE64: 714 MB/Sec
> WRITE: 580 MB/Sec (Tricky)
>
> ---> VIDEO BUS <---
> READ:  691 MB/Sec
> WRITE: 662 MB/Sec
>
> The results have some jitter but both the higher values and that the
> function is gone from the profile can prove the series has an effect.
> If nothing else then simplifying the code a bit. For comparison this
> is faster than a real sam460ex but much slower than running the same
> with -M pegasos2 so embedded PPC TLB emulation still might need some
> improvement. I know these are different and PPC440 has software
> assisted TLB but the problem with it seems to be too much tlb_flushes
> not that it needs more exceptions.
>
> (If somebody is interested to reproduce and experiment with it the
> benchmarks and some results are available from here:
> https://www.amigans.net/modules/newbb/viewtopic.php?topic_id=9226
> some of the tests also have MorphOS versions that's easier to get than
> AmigaOS or sources that could be compiled under Linux.)
>
> Regards,
> BALATON Zoltan
>
> BALATON Zoltan (7):
>    target/ppc: Remove single use function
>    target/ppc: Remove "ext" parameter of ppcemb_tlb_check()
>    target/ppc: Move ppcemb_tlb_search() to mmu_common.c
>    target/ppc: Remove some unneded line breaks
>    target/ppc: Simplify ppcemb_tlb_search()
>    target/ppc: Change ppcemb_tlb_check() to return bool
>    target/ppc: Eliminate goto in mmubooke_check_tlb()
>
>   target/ppc/cpu.h        | 13 ++----
>   target/ppc/mmu_common.c | 91 +++++++++++++++++++++++------------------
>   target/ppc/mmu_helper.c | 32 +--------------
>   3 files changed, 57 insertions(+), 79 deletions(-)