Re: Increasing file descriptors with Linux (again :-()

Darren Steven wrote:

> It would be really nice to change this on the fly (after a squid reconfig),
> and not have to mess with the kernel sources at all.

There should be no need to mess with the Linux 2.2.12 kernel sources
unless you have third-party drivers installed. Changing __FD_SETSIZE in
/usr/include/bits/types.h and running a recent glibc version (2.1.1 or
later) should be sufficient.

Reasons to mess with the kernel sources/headers:
a) You have source to third-party drivers which depends on fd_set or
other FD_SETSIZE dependent structures.
b) You do not normally have root access to the machine which makes it
hard to run "ulimit -HSn xxx" each time Squid is started or rebuilt.

The need to change the glibc header /usr/include/bits/types.h might be
resolved in time now when the Linux kernel no longer has a fixed fd_set
size. I guess the headers are written the way they are to prevent people
from accidently overrunning previous kernel versions which had a fixed
limit of 1024. Linux headers is currently a bit messy in that there are
glibc includes headers which are in large dependent on the kernel and
also duplicated in the kernel headers.

--
Henrik Nordstrom
Spare time Squid hacker