bug#66288: 29.1; Performance regression using pipe for subprocess

[Dmitry Gutov]

On 05/10/2023 01:49, Paul Eggert wrote:
> > +      fcntl (inchannel, F_SETPIPE_SZ, readmax);
>
> This call can fail if you aren't root and you exceed the system limit in 
> /proc/sys/fs/pipe-max-size. So I suggest that if this fnctl fails with 
> EPERM, trying it again after clipping to that limit.

Perhaps we'd rather fail loudly, so the user is aware that their 
customized value cannot be applied.