default buffer size is too small

It appears the default 4096 byte buffer size is too small on a semi-busy system. The first or subsequent read() calls will fail with EOVERFLOW:

# fatrace
read: Value too large for defined data type

syscall_300(0, 0, 0x7f31170a4138, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) = 0x3
syscall_301(0x3, 0x11, 0x4800003b, 0xffffff9c, 0x401a00, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) = 0
brk(0) = 0xd53000
brk(0xd76000) = 0xd76000
rt_sigaction(SIGINT, {0x4018e0, [], SA_RESTORER, 0x7f3116d514f0}, NULL, 8) = 0
read(3, "\30\0\0\0\3\0\30\0 \0\0\0\0\0\0\0\4\0\0\0Q1\0\0", 4096) = 24
open("/proc/12625/comm", O_RDONLY) = 5
[...]
close(5) = 0
read(3, 0xd54000, 4096) = -1 EOVERFLOW (Value too large for defined data type)
dup(2) = 4
fcntl(4, F_GETFL) = 0x8002 (flags O_RDWR|O_LARGEFILE)
fstat(4, {st_mode=S_IFCHR|0600, st_rdev=makedev(136, 13), ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f31172c5000
lseek(4, 0, SEEK_CUR) = -1 ESPIPE (Illegal seek)
write(4, "read: Value too large for define"..., 44read: Value too large for defined data type
) = 44
close(4) = 0

Increasing it to 256kb fixed the issue for me.