Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH] cpufreq: pass policy to ->get() driver callback | Date | Thu, 10 Sep 2015 23:40:16 +0200 |
| |
On Thursday, September 10, 2015 06:52:22 AM Viresh Kumar wrote: > On 10-09-15, 03:41, Rafael J. Wysocki wrote:
[cut]
> > Passing a pointer and dereferencing it is generally less efficient than passing > > a number. Before the patch the core has to do the dereference before calling > > ->get, so it likely doesn't matter here, but the code churn from this change > > is quite substantial and the benefit from it is in the noise IMO. > > Hmm.. Actually almost every other callback (bios_limit() is another > one), passes the policy to the driver, and I thought always passing > the policy will make it more symmetrical. And the expectation that the > cpufreq drivers wouldn't need to use policy from the ->get() callback > would be wrong. Even if there are only few users today. One is the > acpi-cpufreq driver and others are the ones, that are using > cpufreq_generic_get() :)
So the whole question is whether or not this is worth the whole code churn related to the exchange of callbacks.
At this point I really don't know. It depends on the design discussion I'd like to start.
Thanks, Rafael
| |