Re: [PATCH 01/14] x86/cqm: Intel Resource Monitoring Documentation

From: Shivappa Vikas
Date: Fri Dec 23 2016 - 16:42:18 EST




On Fri, 23 Dec 2016, Peter Zijlstra wrote:

Also, the 'whoops you ran out of RMIDs, please reboot' thing totally and
completely blows.

Well, this is really a hardware limitation. User cannot monitor more events on a package than # of RMIDs at the *same time*. The 10/14 reuses the RMIDs that are not monitored anymore. User can monitor more events once he stops monitoring some..

So we throw error at the read (LAZY mode) or open(NOLAZY mode) ..