Linux getrandom() vDSO Patch Updated For ~15x Speedup

[Cape]

I find it both weird and a little irritating how obsessive we are over random numbers. It seems like every 2 months, there's yet another change with how they work. Anyone who actually cares enough should not be using software-based random numbers.

It's just that random numbers are a cool subject, bro

That, and security/privacy

[hotaru]

1) Userspace wants faster cryptographically secure random numbers of arbitrary size, big or small.

faster than this?

$ (for i in `seq 0 31`; do dd if=/dev/urandom bs=2M & done)|dd of=/dev/null bs=2M iflag=fullblock count=128
128+0 records in
128+0 records out
268435456 bytes (268 MB, 256 MiB) copied, 0.435794 s, 616 MB/s

surely 616 MB/s (4.93 Gbps) is fast enough for any real-world use, isn't it?

even my Chromebook (Celeron N4020) does 223 MB/s (1.78 Gbps):

$ (for i in `seq 0 1`; do dd if=/dev/urandom bs=2M & done)|dd of=/dev/null bs=2M iflag=fullblock count=128
128+0 records in
128+0 records out
268435456 bytes (268 MB, 256 MiB) copied, 1.20541 s, 223 MB/s