Nice tip, thanks.

Related: The experimental async aware (io_uring optimized) Glommio API may eventually supplant POSIX I/O.

https://github.com/DataDog/glommio

"Modern storage is plenty fast. It is the APIs that are bad." https://itnext.io/modern-storage-is-plenty-fast-it-is-the-ap...

I'm not aware of an O_DIRECT version of cat. The (older) GNU cat (GNU coreutils 0.83) I just looked at doesn't seem to support it.

There is however GNU dd which supports direct i/o ('direct' flag) for ages.

except that the fastest (and also parallel) versions of grep tend to use memory mapping. for grep it tends to be more linear (except the parallel case), but for others like sort it might not be the case that linear access to the file is always best.