Wow, this does 160 MiB/s. That's a huge improvement! The output of strace looks completely different: poll([{fd=1, events=POLLOUT}], 1, 0) = 1 ([{fd=1, re

Wow, this does 160 MiB/s. That's a huge improvement! The output of strace looks completely different: poll([{fd=1, events=POLLOUT}], 1, 0) = 1 ([{fd=1, revents=POLLOUT}]) write(1, "11111111111111111111111111111111"..., 8192) = 8192 poll([{fd=1, events=POLLOUT}], 1, 0) = 1 ([{fd=1, revents=POLLOUT}]) write(1, "11111111111111111111111111111111"..., 8192) = 8192 With the recursive code, it buffered the output in the same way but bugged the kernel a whole lot more in-between writes. Not exactly sure what is going on: poll([{fd=1, events=POLLOUT}], 1, 0) = 1 ([{fd=1, revents=POLLOUT}]) write(1, "11111111111111111111111111111111"..., 8192) = 8192 rt_sigprocmask(SIG_BLOCK, [INT], [], 8) = 0 clock_gettime(CLOCK_PROCESS_CPUTIME_ID, {tv_sec=0, tv_nsec=920390843}) = 0 rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0 rt_sigprocmask(SIG_BLOCK, [INT], [], 8) = 0 clock_gettime(CLOCK_PROCESS_CPUTIME_ID, {tv_sec=0, tv_nsec=920666397}) = 0 ... rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0 poll([{fd=1, events=POLLOUT}], 1, 0) = 1 ([{fd=1, revents=POLLOUT}]) write(1, "11111111111111111111111111111111"..., 8192) = 8192