StackOverflow
测试代码. 静态数组可以在堆栈上分配,而不是使用堆。堆栈的大小有限,在某些情况下,静态数组可能会耗尽进程所允许的堆栈空间。
program arraymemuse iso_fortran_envimplicit noneinteger, parameter :: n = 2*1024*1024 - 4096print *, 'Numeric Storage (bits): ', numeric_storage_sizeprint *, 'Creating array N ', ncall meanArray(n)containssubroutine meanArray(n)integer, intent(in) :: ninteger :: dumbinteger, dimension(n) :: aa = 1!print *, sum(a)read *, dumbend subroutine meanArrayend program arraymem
检查系统堆栈内存限制
$> ulimit -S -s
8192
$> ulimit -H -s
unlimited
堆栈的软限制为8MB,用户可以将其值提高到无限值。
命令pmap将打印内存映射,内含堆栈标记。
$> pmap -x `ps ax | grep a.ou[t] | awk '{print $1}' | head -1`
输出
Now we will compile the code above with gfortran, forcing the static arrays to be on stack. Some compilers move large arrays to heap automatically so we are bypassing this protection.$> gfortran -fstack-arrays example_12.f90
$> ./a.out
Sometimes you will get an output like this:Numeric Storage (bits): 32Creating array N 2093056
Segmentation fault (core dumped)
We are so close to filling the stack that small variations in loading libraries could cross the limit. Try a few times until the code stops when asking for input from the keyboard.Once the code is waiting for any input, execute this command on a separate terminal:$> pmap -x `ps ax | grep a.ou[t] | awk '{print $1}' | head -1`
The command pmap will print a map of the memory and the stack is marked there.Address Kbytes RSS Dirty Mode Mapping
0000000000400000 4 4 0 r---- a.out
0000000000401000 4 4 0 r-x-- a.out
0000000000402000 4 4 0 r---- a.out
0000000000403000 4 4 4 r---- a.out
0000000000404000 4 4 4 rw--- a.out
0000000001a3e000 132 16 16 rw--- [ anon ]
00007f8fb9948000 1808 284 0 r-x-- libc-2.17.so
00007f8fb9b0c000 2044 0 0 ----- libc-2.17.so
00007f8fb9d0b000 16 16 16 r---- libc-2.17.so
00007f8fb9d0f000 8 8 8 rw--- libc-2.17.so
00007f8fb9d11000 20 12 12 rw--- [ anon ]
00007f8fb9d16000 276 16 0 r-x-- libquadmath.so.0.0.0
00007f8fb9d5b000 2048 0 0 ----- libquadmath.so.0.0.0
00007f8fb9f5b000 4 4 4 r---- libquadmath.so.0.0.0
00007f8fb9f5c000 4 4 4 rw--- libquadmath.so.0.0.0
00007f8fb9f5d000 92 24 0 r-x-- libgcc_s.so.1
00007f8fb9f74000 2044 0 0 ----- libgcc_s.so.1
00007f8fba173000 4 4 4 r---- libgcc_s.so.1
00007f8fba174000 4 4 4 rw--- libgcc_s.so.1
00007f8fba175000 1028 64 0 r-x-- libm-2.17.so
00007f8fba276000 2044 0 0 ----- libm-2.17.so
00007f8fba475000 4 4 4 r---- libm-2.17.so
00007f8fba476000 4 4 4 rw--- libm-2.17.so
00007f8fba477000 2704 220 0 r-x-- libgfortran.so.5.0.0
00007f8fba71b000 2048 0 0 ----- libgfortran.so.5.0.0
00007f8fba91b000 4 4 4 r---- libgfortran.so.5.0.0
00007f8fba91c000 8 8 8 rw--- libgfortran.so.5.0.0
00007f8fba91e000 136 108 0 r-x-- ld-2.17.so
00007f8fbab29000 16 16 16 rw--- [ anon ]
00007f8fbab3d000 8 8 8 rw--- [ anon ]
00007f8fbab3f000 4 4 4 r---- ld-2.17.so
00007f8fbab40000 4 4 4 rw--- ld-2.17.so
00007f8fbab41000 4 4 4 rw--- [ anon ]
00007ffd65b94000 8192 8192 8192 rw--- [ stack ]
00007ffd663d3000 8 4 0 r-x-- [ anon ]
ffffffffff600000 4 0 0 r-x-- [ anon ]
---------------- ------- ------- -------
total kB 24744 9056 8324
参考
Stack overflow error