On 10/01/2015 03:50 PM, Kay Sievers wrote: > On Thu, Oct 1, 2015 at 9:30 PM, Steve Dickson <ste...@redhat.com> wrote: >> >> >> On 10/01/2015 09:24 AM, Kay Sievers wrote: >>> On Wed, Sep 30, 2015 at 10:49 PM, Steve Dickson <ste...@redhat.com> wrote: >>>> Is there a way for systemd to monitor kernel process? >>>> By monitor I mean the existence. >>> >>> No, and there is no plan to do anything like that. >>> >>> Kernel tasks are kernel internals, and userspace must not make any >>> assumptions about them. They can come and go at any time between any >>> kernel versions. >>> >>> Custom tools can do what they need, but systemd should not offer to do >>> that to users. >> First all thanks for the response >> >> kernel process in question is nfsd. The number of thread >> is kept in /proc/fs/nfsd/threads. >> >> So the idea would be doing a systemctl status nfsd >> and number in /proc/fs/nfsd/threads is zero the >> service would be deactive. An non-zero number the >> service would active. >> >> Is this something systemd could be used for? > > No, not directly. There is no facility to watch /proc or any other > similar interface for such changes. Plain /proc directories are just > not capable of providing event information to userspace. Gotcha...
> > The kernel's nfs implementation would need a character device where > events are send out, or possibly a poll()able file in /proc, or > something in /sys/devices/, or a similar approach, where udev can > react to. Such interface could be used to signal systemd that > userspace should react to state changes in the kernel. Hmm... Interesting idea... Thanks! steved. _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
