[systemd-devel] device enumeration by systemd user instances

[Greg KH]

On Wed, Jul 17, 2019 at 05:46:58PM +0200, Pawel Szewczyk wrote:
> Dear all
> 
> I was recently working on reducing booting time and I see one issue that 
> I think is worth discussing.
> 
> The problem is the device units enumeration seems to take a long time 
> (>100ms in our case) before any units are beginning to start.

100ms seems like a really long time, what exactly is it doing during
that time?  Is the kernel spending too much time regenerating the
uevents?

How many devices are you talking about?  Any chance to see what really
is happening here by running perf to see where the hot-spots are?

thanks,

greg k-h