On 07/11/17 21:42, Andrew Pinski wrote: > On Tue, Jul 11, 2017 at 12:31 PM, Andrew Pinski <pins...@gmail.com> wrote: >> On Tue, Jul 11, 2017 at 12:27 PM, Andrew Pinski <pins...@gmail.com> wrote: >>> On Tue, Jul 11, 2017 at 12:15 PM, Bernd Edlinger >>> <bernd.edlin...@hotmail.de> wrote: >>>> Hi, >>>> >>>> I see this now as well on Ubuntu 16.04, but I doubt that the Kernel is >>>> to blame. >>> >>> I don't see these failures when I use a 4.11 kernel. Only with a 4.4 >>> kernel. >>> Also the guality testsuite does not run at all with a 4.4 kernel, it >>> does run when using a 4.11 kernel; I suspect this is the same symptom >>> of the bug. >> >> >> 4.11 kernel results (with CentOS 7.4 glibc): >> https://gcc.gnu.org/ml/gcc-testresults/2017-07/msg00998.html >> >> 4.4 kernel results (with ubuntu 1604 glibc): >> https://gcc.gnu.org/ml/gcc-testresults/2017-07/msg01009.html >> >> Note the glibc does not matter here as I get a similar testsuite >> results as the CentOS 7.4 glibc using the Ubuntu 1604 glibc but with >> the 4.11 kernel. >> >> Also note I get a similar results with a plain 4.11 kernel compared to >> the above kernel. > > > Maybe commit 6a7e6f78c235975cc14d4e141fa088afffe7062c or > 0f40fbbcc34e093255a2b2d70b6b0fb48c3f39aa to the kernel fixes both > issues. >
As Georg-Johann points out here: https://gcc.gnu.org/ml/gcc/2017-07/msg00028.html updating the kernel alone does not fix the issue. These patches do all circle around pty and tty devices, but in the strace file I see a pipe(2) command creating the fileno 10 and the sequence of events is as follows: pipe([7, 10]) = 0 (not in my previous e-mail) clone() = 16141 clone() = 16142 write(4, "spawn: returns {0}\r\n", 20) = 20 --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=16141, --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=16142, read(10,...,4096) = 4096 read(10,...,4096) = 2144 read(10, "", 4096) = 0 close(10) = 0 wait4(16141, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, NULL) = 16141 wait4(16142, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, NULL) = 16142 All data arrive at the expect process, but apparently too quickly. Thanks Bernd.
