[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Performance hit in qemu-system-ppc

From: Howard Spoelstra
Subject: Performance hit in qemu-system-ppc
Date: Sun, 26 Jan 2020 00:30:02 +0100


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,

reply via email to

[Prev in Thread] Current Thread [Next in Thread]