Re: Performance hit in qemu-system-ppc

[BALATON Zoltan]

Hello,

cc-ing the ppc list, maintainer and original author of the patch could 
increase the chances that they actually see your message which they might 
miss on qemu-devel. David explicitely said he usually cannot read all 
mails on qemu-devel so likely should be cc-d on all PPC issues (or also cc 
the qemu-ppc list besides qemu-devel).

Regards,
BALATON Zoltan

On Sun, 26 Jan 2020, Howard Spoelstra wrote:
> Hi,
>
> I noticed a considerable (~20%) slowdown in the cpu performance of
> qemu-system-ppc.
> Bisecting led me to this commit:
>
> d03f140804b345a85973976506492027f703d82d is the first bad commit
> commit d03f140804b345a85973976506492027f703d82d
> Author: Richard Henderson <address@hidden>
> Date:   Mon Dec 9 13:49:58 2019 -0800
>
>    cputlb: Move body of cpu_ldst_template.h out of line
>
>    With the tracing hooks, the inline functions are no longer
>    so simple.  Once out-of-line, the current tlb_entry lookup
>    is redundant with the one in the main load/store_helper.
>
>    This also begins the introduction of a new target facing
>    interface, with suffix *_mmuidx_ra.  This is not yet
>    official because the interface is not done for user-only.
>
>    Use abi_ptr instead of target_ulong in preparation for
>    user-only; the two types are identical for softmmu.
>
>    What remains in cpu_ldst_template.h are the expansions
>    for _code, _data, and MMU_MODE<N>_SUFFIX.
>
>    Tested-by: Philippe Mathieu-Daudé <address@hidden>
>    Signed-off-by: Richard Henderson <address@hidden>
>
> accel/tcg/cputlb.c               | 116 ++++++++++++++++++++++++++++++++++++
> include/exec/cpu_ldst.h          |  25 +++++++-
> include/exec/cpu_ldst_template.h | 125
> ++++++++-------------------------------
> 3 files changed, 166 insertions(+), 100 deletions(-)
>
> Thanks for looking into this issue,
> Howard