Re: ATF X86 race with Debug Registers
On 10.03.2018 22:47, Andreas Gustafsson wrote: > Kamil Rytarowski wrote: >> Sometimes we catch a bug with Debug Registers in the ptrace(2) tests: >> >> NetBSD/amd64 >> http://releng.netbsd.org/b5reports/amd64/2018/2018.03.06.11.21.31/test.html#lib_libc_sys_t_ptrace_wait6_dbregs_dr3_trap_variable_readwrite_write_2bytes >> >> NetBSD/i386 >> http://releng.netbsd.org/b5reports/i386/2017/2017.12.06.17.54.58/test.html#lib_libc_sys_t_ptrace_wait3_dbregs_dr2_trap_variable_readwrite_read_2bytes >> >> I was trying to reproduce this locally on a real hardware and in qemu >> (softemu), including concurrent execution, but after merely 100M >> attempts to reproduce the test-case, I've not encountered a single failure. >> >> Are there some special properties of these releng machines? qemu+kvm? > > Nothing special about it AFAIK, it's just qemu from pkgsrc running on > babylon5.netbsd.org, a dual Xeon L5630, under NetBSD 7.1_STABLE. > Typical load is 6-8 qemu processes and a niced -j 16 build. There's > no kvm - that's only supported under Linux. > > If you look at the test.log file corresponding to the test.html, you > can find the qemu version and full qemu command line near the top. > I've reproduced this failure locally in qemu, after 50-100k iterations of a test using Debug Register and trapping a variable I can see that instead of SIGTRAP, I'm receiving SIGSTOP. Reproducing can take like 2h, but I will try to investigate this. signature.asc Description: OpenPGP digital signature
Re: ATF X86 race with Debug Registers
Kamil Rytarowski wrote: > Sometimes we catch a bug with Debug Registers in the ptrace(2) tests: > > NetBSD/amd64 > http://releng.netbsd.org/b5reports/amd64/2018/2018.03.06.11.21.31/test.html#lib_libc_sys_t_ptrace_wait6_dbregs_dr3_trap_variable_readwrite_write_2bytes > > NetBSD/i386 > http://releng.netbsd.org/b5reports/i386/2017/2017.12.06.17.54.58/test.html#lib_libc_sys_t_ptrace_wait3_dbregs_dr2_trap_variable_readwrite_read_2bytes > > I was trying to reproduce this locally on a real hardware and in qemu > (softemu), including concurrent execution, but after merely 100M > attempts to reproduce the test-case, I've not encountered a single failure. > > Are there some special properties of these releng machines? qemu+kvm? Nothing special about it AFAIK, it's just qemu from pkgsrc running on babylon5.netbsd.org, a dual Xeon L5630, under NetBSD 7.1_STABLE. Typical load is 6-8 qemu processes and a niced -j 16 build. There's no kvm - that's only supported under Linux. If you look at the test.log file corresponding to the test.html, you can find the qemu version and full qemu command line near the top. -- Andreas Gustafsson, g...@gson.org
ATF X86 race with Debug Registers
Sometimes we catch a bug with Debug Registers in the ptrace(2) tests: NetBSD/amd64 http://releng.netbsd.org/b5reports/amd64/2018/2018.03.06.11.21.31/test.html#lib_libc_sys_t_ptrace_wait6_dbregs_dr3_trap_variable_readwrite_write_2bytes NetBSD/i386 http://releng.netbsd.org/b5reports/i386/2017/2017.12.06.17.54.58/test.html#lib_libc_sys_t_ptrace_wait3_dbregs_dr2_trap_variable_readwrite_read_2bytes I was trying to reproduce this locally on a real hardware and in qemu (softemu), including concurrent execution, but after merely 100M attempts to reproduce the test-case, I've not encountered a single failure. Are there some special properties of these releng machines? qemu+kvm? signature.asc Description: OpenPGP digital signature
