> -----Original Message----- > From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx] > Sent: Sunday, September 10, 2017 1:10 AM > To: KY Srinivasan <kys@xxxxxxxxxxxxx> > Cc: linux-kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; > olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx; vkuznets@xxxxxxxxxx; > jasowang@xxxxxxxxxx; leann.ogasawara@xxxxxxxxxxxxx; > marcelo.cerri@xxxxxxxxxxxxx; Stephen Hemminger > <sthemmin@xxxxxxxxxxxxx>; Dexuan Cui <decui@xxxxxxxxxxxxx>; Haiyang > Zhang <haiyangz@xxxxxxxxxxxxx> > Subject: Re: [PATCH 2/5] vmbus: suppress uevents for hv_sock devices > > On Sat, Sep 09, 2017 at 11:08:46PM -0700, kys@xxxxxxxxxxxxxxxxxxxxxx > wrote: > > From: Dexuan Cui <decui@xxxxxxxxxxxxx> > > > > hv_sock driver is automatically loaded when an application creates an > > AF_VSOCK socket, so we don't really need to trigger uevents to the user > > space udevd. > > > > And hv_sock devices can appear and disappear frequency, e.g. 100 per > > second, so triggering the udevents can cause a high cpu utilization of > > udevd, e.g. 30% on a 2-cpu virtual machine. So let's suppress the > > uevents to avoid this. > > 100 per second for a struct device? That's crazy, and the uevent is the > least of your worries. Please fix that, as it's not the correct way to > use the driver model at all. > > And really, why is uevent taking all that much cpu time anyway? It > _should_ be pretty fast, unless your distro is doing crazy things with > it... > > sorry, am not going to take this patch. Greg, This is not a real problem that needs fixing. The test automation triggered this condition. I will drop this patch and send the rest. Regards, K. Y > > greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
