Le 16/03/2017 à 18:31, Alex Bennée a écrit : > > Laurent Vivier writes: > >> Le 27/02/2017 à 15:38, Alex Bennée a écrit : >>> >>> Laurent Vivier writes: >>> >>>> Le 24/02/2017 à 12:20, Alex Bennée a écrit : >>>>> There are a couple of changes that occur at the same time here: >>>>> >>>>> - introduce a single vCPU qemu_tcg_cpu_thread_fn >>>>> >>>>> One of these is spawned per vCPU with its own Thread and Condition >>>>> variables. qemu_tcg_rr_cpu_thread_fn is the new name for the old >>>>> single threaded function. >>>>> >>>>> - the TLS current_cpu variable is now live for the lifetime of MTTCG >>>>> vCPU threads. This is for future work where async jobs need to know >>>>> the vCPU context they are operating in. >>>>> >>>>> The user to switch on multi-thread behaviour and spawn a thread >>>>> per-vCPU. For a simple test kvm-unit-test like: >>>>> >>>>> ./arm/run ./arm/locking-test.flat -smp 4 -accel tcg,thread=multi >>>>> >>>>> Will now use 4 vCPU threads and have an expected FAIL (instead of the >>>>> unexpected PASS) as the default mode of the test has no protection when >>>>> incrementing a shared variable. >>>>> >>>>> We enable the parallel_cpus flag to ensure we generate correct barrier >>>>> and atomic code if supported by the front and backends. This doesn't >>>>> automatically enable MTTCG until default_mttcg_enabled() is updated to >>>>> check the configuration is supported. >>>> >>>> This commit breaks linux-user mode: >>>> >>>> debian-8 with qemu-ppc on x86_64 with ltp-full-20170116 >>>> >>>> cd /opt/ltp >>>> ./runltp -p -l "qemu-$(date +%FT%T).log" -f /opt/ltp/runtest/syscalls -s >>>> setgroups03 >>>> >>>> setgroups03 1 TPASS : setgroups(65537) fails, Size is > >>>> sysconf(_SC_NGROUPS_MAX), errno=22 >>>> qemu-ppc: /home/laurent/Projects/qemu/include/qemu/rcu.h:89: >>>> rcu_read_unlock: Assertion `p_rcu_reader->depth != 0' failed. >>>> qemu-ppc: /home/laurent/Projects/qemu/include/qemu/rcu.h:89: >>>> rcu_read_unlock: Assertion `p_rcu_reader->depth != 0' failed. >>>> qemu-ppc: /home/laurent/Projects/qemu/include/qemu/rcu.h:89: >>>> rcu_read_unlock: Assertion `p_rcu_reader->depth != 0' failed. >>>> ... >>> >>> Interesting. I can only think the current_cpu change has broken it >>> because most of the changes in this commit affect softmmu targets only >>> (linux-user has its own run loop). >>> >>> Thanks for the report - I'll look into it. >> >> After: >> >> 95b0eca Merge remote-tracking branch >> 'remotes/stsquad/tags/pull-mttcg-fixups-090317-1' into staging >> >> [Tested with my HEAD on: >> b1616fe Merge remote-tracking branch >> 'remotes/famz/tags/docker-pull-request' into staging] >> >> I have now: >> >> <<>> >> tag=setgroups03 stime=1489413401 >> cmdline="setgroups03" >> contacts="" >> analysis=exit >> <<>> >> ** >> ERROR:/home/laurent/Projects/qemu/cpu-exec.c:656:cpu_exec: assertion >> failed: (cpu == current_cpu) >> ** > > Sorry about the delay. After lengthy fighting to get LTP on PowerPC > built I got this behaviour: > > 17:26 alex@zen taken:41, git:mttcg/more-fixes-for-rc1, [/home/alex/lsrc/qemu/qemu.git]> sudo ./ppc-linux-user/qemu-ppc ./ppc-linux-user/setgroups03 > setgroups03 1 TPASS : setgroups(65537) fails, Size is > sysconf(_SC_NGROUPS_MAX), errno=22 > setgroups03 2 TBROK : tst_sig.c:233: unexpected signal SIGSEGV(11) received (pid = 22137). > setgroups03 3 TBROK : tst_sig.c:233: Remaining cases broken I've just tested with master (272d7de) and I always have the "(cpu == current_cpu)". I think this test has never worked correctly (I mean I had also the SIGSEGV signal before), what is annoying here is the infinite loop generated by this error (the test never ends). > > I'm afraid I can't compare the result to real hardware so maybe my LTP > build is broken. But the main thing is I can't seem to reproduce it > here. In attachment. > Could you ping me your LTP binary so I can have a look? > > The other thing to note is the assert you now see firing is a guard for > buggy compilers. What version are you building with and can you try any > other versions? gcc (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1) Laurent