From: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx> Date: Tue, 26 May 2015 16:21:09 -0700 > The current algorithm for deciding on the number of VRSS channels is > not optimal since we open up the min of number of CPUs online and the > number of VRSS channels the host is offering. So on a 32 VCPU guest > we could potentially open 32 VRSS subchannels. Experimentation has > shown that it is best to limit the number of VRSS channels to the number > of CPUs within a NUMA node. As part of this work introduce a module > parameter to control the number of sub-channels we would open up as well. > Here is the new algorithm for deciding on the number of sub-channels we > would open up: > 1) Pick the minimum of what the host is offering and what the driver > in the guest is specifying via the module parameter. > 2) Pick the minimum of (1) and the numbers of CPUs in the NUMA > node the primary channel is bound to. > > Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> No new module parameters, sorry. You will have to make it such that this can be changed at run time, and use a generic run-time mechanism to configure this value that any driver can use. I will not accept: "this is not possible" or "this is too hard" as a reason why you have to use a module parameter. Settings that cannot be set at run time are painful for people who run large scale operations where resetting entire systems to change a setting is completely and utterly impractical. _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
