From a092a95547710bcbb8c168e5ec03f55fb4ab1ad7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Mon, 23 Mar 2020 16:15:09 +0000 Subject: [PATCH] configure: disable MTTCG for MIPS guests MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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=0 clocksource=GIC console=tty0 console=ttyS0 panic=-1" \ --no-reboot 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=single" the instability goes away. Results summary: 0: 100 times (100.00%), avg time 17.318 (249.76 varience/15.80 deviation) 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. In lieu of someone tracking down the failure lets disable it for now. Signed-off-by: Alex Bennée Acked-by: Philippe Mathieu-Daudé Reviewed-by: Philippe Mathieu-Daudé Acked-by: Richard Henderson Reviewed-by: Aleksandar Markovic Cc: Aurelien Jarno Cc: Aleksandar Rikalo Message-Id: <20200323161514.23952-7-alex.bennee@linaro.org> --- configure | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/configure b/configure index 89fe881dd4..e225a1e3ff 100755 --- a/configure +++ b/configure @@ -7887,7 +7887,7 @@ case "$target_name" in TARGET_SYSTBL_ABI=n32 ;; mips64|mips64el) - mttcg="yes" + mttcg="no" TARGET_ARCH=mips64 TARGET_BASE_ARCH=mips echo "TARGET_ABI_MIPSN64=y" >> $config_target_mak