On Sat, May 04, 2019 at 07:42:06AM +0000, Laurent Bercot wrote: > > > If mdev is used as kernel hotplug helper and the system generates many > > hotplug events it will quickly consume considerable resources because a > > process is forked for each event and, if the mdev.seq feature is used, > > they must also coordinate among each other. While the uevent applet > > mitigates some of the resource problems you still have to pay the cost > > for a fork/exec and parsing of mdev.conf for each event. > > Doing it that way spares the fork/exec indeed, but you're still > parsing mdev.conf for every event. The parsing is done in > make_device(), which is called at least once per event. And there's > no way to prevent that - that's just how mdev is structured. > To parse mdev.conf only once and have a really fast code path on > event reception, you'd basically need to rewrite mdev entirely.
Actually that is not the case anymore. There was already code for the '-s' case that parsed mdev.conf only once and stored the rules in G.rule_vec. The daemon mode just reuses this. Maybe it could be optimized further but it was sufficient for us. > Are you aware of https://skarnet.org/software/mdevd/ ? :) Oh, actually not. Looks indeed interesting. I'll have a look... Regards, Jan _______________________________________________ busybox mailing list busybox@busybox.net http://lists.busybox.net/mailman/listinfo/busybox
