On Fri, Jul 19, 2019 at 12:14 AM David Miller <davem@xxxxxxxxxxxxx> wrote: > > So this ended up as commit 7b9afb86b6328f10dc2cad9223d7def12d60e505 > > (thanks to Anatoly for bisecting) and introduced a regression: > > futex.test from the strace test suite now causes an Oops on sparc64 > > in futex syscall. > > > > Here is a heavily stripped down reproducer: > > Does not reproduce for me on a T4-2 machine. > > So this problem might depend on the type of system you are on, > I suspect it's one of those "pre-Niagara vs. Niagara and later" > situations because that's the dividing line between two set of > wildly different TLB and cache management methods. > > What kind of machine are you on? David, the first test where it was discovered was done on my test LDOM named ttip, hardware (hypervisor) is T5-2 server, running under Solaris 11.4 OS. ttip LDOM is debian sparc64 unstable , so with almost all the latest software (gcc 8.3.0, binutils 2.32.51.20190707-1, debian GLIBC 2.28-10, etc..) For another test, i also installed LDOM with oracle sparc linux https://oss.oracle.com/projects/linux-sparc/ , but I've to install a more fresh version of gcc on it first, since system installed gcc 4.4 is too old for a git kernel (linux-2.6/Documentation/Changes lists gcc 4.6 as a minimal version), so I choose to install gcc-7.4.0 to /opt/ (leaving system installed gcc 4.4 under /usr/bin). Compiled and installed git kernel version, i.e. last tag 5.3.0-rc1 and ran the test. Kernel still produced oops.
