Port locks with high time under LCNT

[Mikael Pettersson]

On Thu, Jan 2, 2020 at 5:38 PM Frank Muller <frank.muller.erl@REDACTED> wrote:
>
> Thanks to @Peti Gömöri, I was able to identify these Port locks:
> https://gist.github.com/frankmullerl/008174c6594ca27584ac7f4e6724bee5
>
> Some of them are taking up to 6.7sec (6707846 usec) :-/
>
> My application is serving static images by calling file:sendfile/2 (https://erlang.org/doc/man/file.html#sendfile-2).
>
> Can someone please explain how I can avoid these locks or at least make their impact lesser?

Using the file module has been known to cause synchronization
overheads.  Often we (Klarna) use prim_file instead,
but it has sendfile/8 not /2.  Anyway, that may be an avenue worth
investigating.