Re: Remove the limit on the number of entries allowed in catcaches,

"Simon Riggs" <simon(at)2ndquadrant(dot)com> wrote
>
> Can we do the same for the file descriptors in fd.c?
>
> Very often the total number of file descriptors is much less than the
> maximum, so it would make sense to only maintain the LRU when we are
> using more than 50%-75% of the maximum.
>

I am not against doing it but AFAIR the LRU file operations is (1) not
frequent; (2) the cost is only several CPU circles if we do not run out of
fds; (3) the LRU lseek/close/open big cost is still not avoidable when we
really run out of fds. So this optimization may be not needed. Or do you
have some numbers to show that's a bottleneck for some kind of applications?

Regards,
Qingqing