On Fri, Jan 26, 2018 at 05:34:28PM +0000, Michael Kelley (EOSG) wrote: > > -----Original Message----- > > From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx] > > Sent: Thursday, January 25, 2018 2:00 AM > > To: Michael Kelley (EOSG) <Michael.H.Kelley@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>; KY Srinivasan <kys@xxxxxxxxxxxxx>; x86@xxxxxxxxxx; > > jrp@xxxxxxx > > Subject: Re: [PATCH v2 char-misc 1/1] Drivers: hv: vmbus: Implement Direct Mode for stimer0 > > > > On Mon, Jan 22, 2018 at 03:29:29PM -0700, mikelley@xxxxxxxxxxxxxxxxxxxxxx wrote: > > > +/* > > > + * If false, we're using the old mechanism for stimer0 interrupts > > > + * where it sends a VMbus message when it expires. The old > > > + * mechanism is used if Direct Mode is explicitly disabled > > > + * by the module parameter, or on older versions of Hyper-V > > > + * that don't support Direct Mode. While Hyper-V provides > > > + * four stimer's per CPU, Linux uses only stimer0. > > > + */ > > > +static bool direct_mode_enabled = true; > > > +module_param(direct_mode_enabled, bool, 0444); > > > +MODULE_PARM_DESC(direct_mode_enabled, > > > + "Set to N to disable stimer Direct Mode."); > > > > Ick ick ick. How is a distro or user supposed to know if/when to enable > > this and not to enable it? This isn't ok, can you please make this > > "automatic" to always do the right thing based on what it is running on? > > To be clear, this patch already does the "automatic" thing based on the > capabilities of the hypervisor. But it's often handy to be able to override > the automatic behavior without having to rebuild the kernel. Then put the option somewhere else. sysfs, debugfs, somewhere else. Never a module parameter please, not for new code. thanks, greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
