Emilio G. Cota <c...@braap.org> writes: > On Mon, Oct 03, 2016 at 10:32:55 +0100, Alex Bennée wrote: > (snip) >> However the series as a whole does have value. As you can see from the >> other patches there are some real races being picked up by the sanitizer >> which only really become visible when a) you remove the noise of the >> "false" positives and b) run the test many many times. For example this >> one: >> >> ================== >> WARNING: ThreadSanitizer: data race (pid=24906) >> Read of size 8 at 0x7db4000261f0 by thread T3 (mutexes: write M8203): >> #0 do_tb_flush /home/alex/lsrc/qemu/qemu.git/translate-all.c:872 >> (qemu-arm+0x00006000ce68) >> #1 process_queued_cpu_work >> /home/alex/lsrc/qemu/qemu.git/cpus-common.c:337 (qemu-arm+0x000060116712) >> #2 cpu_loop /home/alex/lsrc/qemu/qemu.git/linux-user/main.c:654 >> (qemu-arm+0x000060052213) >> #3 clone_func /home/alex/lsrc/qemu/qemu.git/linux-user/syscall.c:6070 >> (qemu-arm+0x0000600686fb) >> #4 <null> <null> (libtsan.so.0+0x0000000230d9) >> >> Previous write of size 8 at 0x7db4000261f0 by main thread (mutexes: write >> M8): >> #0 cpu_list_add /home/alex/lsrc/qemu/qemu.git/cpus-common.c:87 >> (qemu-arm+0x000060115b7a) >> #1 cpu_exec_init /home/alex/lsrc/qemu/qemu.git/exec.c:641 >> (qemu-arm+0x000060009900) >> #2 arm_cpu_initfn /home/alex/lsrc/qemu/qemu.git/target-arm/cpu.c:447 >> (qemu-arm+0x0000600f833b) > [..] > > Nice! Which patch fixes this--patch 10? It would be cool to have this > report in the corresponding commit message.
This particular one only actually showed up after I sent the last series - I'd kicked off 1000 repeating tests just before I boarded my flight back home :-) However patch 10 fixes another rare case which is in the class of races caused by creating or destroying a thread just as we flush. > > Thanks, > > Emilio -- Alex Bennée
