Re: [PATCH v5] tools/xenconsoled: Increase file descriptor limit

[Ian Campbell <ian.campbell@citrix.com>]

On Mon, 2015-03-02 at 14:22 +0000, Ian Campbell wrote:
> On Fri, 2015-02-27 at 17:53 +0000, Andrew Cooper wrote:
> > XenServer's VM density testing uncovered a regression when moving from
> > sysvinit to systemd where the file descriptor limit dropped from 4096 to
> > 1024. (XenServer had previously inserted a ulimit statement into its
> > initscripts.)
> > 
> > One solution is to use LimitNOFILE=4096 in xenconsoled.service to match the
> > lost ulimit, but that is only a stopgap solution.
> > 
> > As Xenconsoled genuinely needs a large number of file descriptors if a large
> > number of domains are running, attempt to increase the limit.
> > 
> > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> > CC: Ian Campbell <Ian.Campbell@citrix.com>
> > CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
> > CC: Wei Liu <wei.liu2@citrix.com>
> 
> I tried to apply but I'm afraid that for 32-bit userspace this gives me:
> 
> daemon/main.c: In function 'increase_fd_limit':
> daemon/main.c:89:10: error: format '%lu' expects argument of type 'long unsigned int', but argument 3 has type 'rlim_t' [-Werror=format]
> daemon/main.c:89:10: error: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'rlim_t' [-Werror=format]
> daemon/main.c:89:10: error: format '%lu' expects argument of type 'long unsigned int', but argument 5 has type 'rlim_t' [-Werror=format]
> daemon/main.c:89:10: error: format '%lu' expects argument of type 'long unsigned int', but argument 6 has type 'rlim_t' [-Werror=format]
> 
> I've no idea how one is formally supposed to print and rlim_r.

The Internet(tm) seems to think "by casting to long long" is the
answer :-/

Ian.