Re: [PATCH v2] qemu_init: increase NOFILE soft limit on POSIX

[Daniel P . Berrangé]

On Mon, Dec 18, 2023 at 11:13:40AM +0100, Fiona Ebner wrote:
> In many configurations, e.g. multiple vNICs with multiple queues or
> with many Ceph OSDs, the default soft limit of 1024 is not enough.
> QEMU is supposed to work fine with file descriptors >= 1024 and does
> not use select() on POSIX. Bump the soft limit to the allowed hard
> limit to avoid issues with the aforementioned configurations.
> 
> Of course the limit could be raised from the outside, but the man page
> of systemd.exec states about 'LimitNOFILE=':
> 
> > Don't use.
> > [...]
> > Typically applications should increase their soft limit to the hard
> > limit on their own, if they are OK with working with file
> > descriptors above 1023,
> 
> If the soft limit is already the same as the hard limit, avoid the
> superfluous setrlimit call. This can avoid a warning with a strict
> seccomp filter blocking setrlimit if NOFILE was already raised before
> executing QEMU.
> 
> Buglink: https://bugzilla.proxmox.com/show_bug.cgi?id=4507
> Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
> ---

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>


With regards,
Daniel
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