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X-Received-From: 2a00:1450:4864:20::441 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Aleksandar Rikalo , qemu-devel@nongnu.org, Aurelien Jarno , Philippe =?utf-8?Q?Mathieu-Daud?= =?utf-8?Q?=C3=A9?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Aleksandar Markovic writes: > =D0=BF=D0=B5=D1=82, 20. =D0=BC=D0=B0=D1=80 2020. =D1=83 12:45 Alex Benn= =C3=A9e =D1=98=D0=B5 =D0=BD=D0=B0=D0=BF=D0=B8=D1= =81=D0=B0=D0=BE/=D0=BB=D0=B0: >> >> While debugging check-acceptance failures I found an instability in >> the mips64el test case. Briefly the test case: >> >> retry.py -n 100 -c -- ./mips64el-softmmu/qemu-system-mips64el \ >> -display none -vga none -serial mon:stdio \ >> -machine malta -kernel ./vmlinux-4.7.0-rc1.I6400 \ >> -cpu I6400 -smp 8 -vga std \ >> -append "printk.time=3D0 clocksource=3DGIC console=3Dtty0 console=3D= ttyS0 panic=3D-1" \ >> --no-reboot >> > > Thank for the findings! > > Could you perhaps attach or link to "retry.py"? Sure - it's just a noddy python script which I use for repeated testing: https://github.com/stsquad/retry > Did you run this particular test for the first time now, or it used to > pass before? I only noticed it since it was added to check-acceptance and has been flakey since added I think. > > Thanks, > Aleksandar > >> Reports about a 9% failure rate: >> >> Results summary: >> 0: 91 times (91.00%), avg time 5.547 (0.45 varience/0.67 deviation) >> -6: 9 times (9.00%), avg time 3.394 (0.02 varience/0.13 deviation) >> Ran command 100 times, 91 passes >> >> When re-run with "--accel tcg,thread=3Dsingle" the instability goes >> away. >> >> Results summary: >> 0: 100 times (100.00%), avg time 17.318 (249.76 varience/15.80 deviati= on) >> Ran command 100 times, 100 passes >> >> Which seems to indicate there is some aspect of the MIPS MTTCG fixes >> that has been missed. Ideally we would fix that but I'm afraid I don't >> have time to investigate and am not super familiar with the >> architecture anyway. >> >> I've disabled all the mips guests as I assume it's a fundamental >> synchronisation primitive that is broken but I haven't tested them all >> (there are a lot!). >> >> Signed-off-by: Alex Benn=C3=A9e >> Cc: Aleksandar Markovic >> Cc: Aurelien Jarno >> Cc: Aleksandar Rikalo >> Cc: Philippe Mathieu-Daud=C3=A9 >> --- >> configure | 6 +++--- >> 1 file changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/configure b/configure >> index 206d22c5153..002792d21dc 100755 >> --- a/configure >> +++ b/configure >> @@ -7832,19 +7832,19 @@ case "$target_name" in >> echo "TARGET_ABI32=3Dy" >> $config_target_mak >> ;; >> mips|mipsel) >> - mttcg=3D"yes" >> + mttcg=3D"no" >> TARGET_ARCH=3Dmips >> echo "TARGET_ABI_MIPSO32=3Dy" >> $config_target_mak >> ;; >> mipsn32|mipsn32el) >> - mttcg=3D"yes" >> + mttcg=3D"no" >> TARGET_ARCH=3Dmips64 >> TARGET_BASE_ARCH=3Dmips >> echo "TARGET_ABI_MIPSN32=3Dy" >> $config_target_mak >> echo "TARGET_ABI32=3Dy" >> $config_target_mak >> ;; >> mips64|mips64el) >> - mttcg=3D"yes" >> + mttcg=3D"no" >> TARGET_ARCH=3Dmips64 >> TARGET_BASE_ARCH=3Dmips >> echo "TARGET_ABI_MIPSN64=3Dy" >> $config_target_mak >> -- >> 2.20.1 >> --=20 Alex Benn=C3=A9e