SIGSEGV in AIX extend_brk( ) call
When using a large shared page cache close to the maximum size allowed on AIX (2.75GB), there is a slight risk that a stone or gem process may crash with a SIGSEGV in the AIX system call extend_brk( ), used for allocating C-heap memory. This occurs when all available 32-bit memory space has been utilized.
Log entry will look similar to:
GS Signal Handler: Unhandled signal 11, SIGSEGV Received at XXXXXXXXX
HostFaultHandler: signal (int) = 11
info->si_signo = 11 = 0xb
info->si_code = 51 = 0x33
info->si_errno = 0 = 0x0
info->si_addr = 0x4 pc = 0x2001109c
Registers saved from frame receiving the signal:
Begin attempt to print C-level stack for PID XXXXXXX at: <date> 13501244:
/opt/gemstone/GemStone6.7.0-RISC6000.AIX/sys/stoned -e<config file>
0x2011b2c0 waitpid(??, ??, ??) + 0x1c0
0x1000b228 forkAndWait(const char*,char* const*)() + 0x68
0x1000ae3c HostPrintCStack(long)() + 0x1dc
0x1000a33c HostCoredump(int)() + 0xadc
0x1000d6ac sigCoreExit(int,int,siginfo_t*,void*)() + 0x16c
0x1000bc80 HostFaultHandler() + 0x640
<signal> 0x2001109c extend_brk(??, ??, ??) + 0x2dc
. . .
Workaround
Upgrade to GemStone/64 for the larger 64-bit memory space.
Alternatively, reduce the size of the SPC to allow more room for C heap growth.
Last updated: 7/27/18