Messages in this thread | | | From | KY Srinivasan <> | Subject | RE: [PATCH 2/5] vmbus: suppress uevents for hv_sock devices | Date | Mon, 18 Sep 2017 00:02:33 +0000 |
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> -----Original Message----- > From: Greg KH [mailto:gregkh@linuxfoundation.org] > Sent: Sunday, September 10, 2017 1:10 AM > To: KY Srinivasan <kys@microsoft.com> > Cc: linux-kernel@vger.kernel.org; devel@linuxdriverproject.org; > olaf@aepfle.de; apw@canonical.com; vkuznets@redhat.com; > jasowang@redhat.com; leann.ogasawara@canonical.com; > marcelo.cerri@canonical.com; Stephen Hemminger > <sthemmin@microsoft.com>; Dexuan Cui <decui@microsoft.com>; Haiyang > Zhang <haiyangz@microsoft.com> > Subject: Re: [PATCH 2/5] vmbus: suppress uevents for hv_sock devices > > On Sat, Sep 09, 2017 at 11:08:46PM -0700, kys@exchange.microsoft.com > wrote: > > From: Dexuan Cui <decui@microsoft.com> > > > > 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
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