Confused by function names cpuidle_install_idle_handler/cpuidle_uninstall_idle_handler

[Anand Moon]

Hi Meraj,

Look at the condition where they are called,
If they justify the meaning of the functions
it's ok to keep the name as it is.

Other wise if you have alternate name for these functions,
just send a patch to the maintainers of the code changes.

-Anand Moon


On Tuesday, July 22, 2014 8:38 PM, Mohammad Merajul Islam Molla <meraj.enigma at gmail.com> wrote:
Hi Anand,

Thanks for your reply. I looked up the patch.

Question:
                 Should these functions be renamed now that they don't
do what they used to do earlier?


--
Thanks,
-Meraj


On Tue, Jul 22, 2014 at 8:43 PM, Anand Moon <moon.linux at yahoo.com> wrote:
> Hi Meraj,
>
> Please look at the following commit this will help clear you confusion
>
> git commit id : a0bfa1373859e9d11dc92561a8667588803e42d8
>
>
> patch :0001-cpuidle-stop-depending-on-pm_idle.patch
>
> To generate following patch:
>
> #git format-patch -1 a0bfa1373859e9d11dc92561a8667588803e42d8
>
> 0001-cpuidle-stop-depending-on-pm_idle.patch
>
>
> -Anand Moon
>
>
> On Tuesday, July 22, 2014 7:28 PM, Mohammad Merajul Islam Molla <meraj.enigma at gmail.com> wrote:
> Hello,
>
> As mentioned, the code excerpt was from kernel version 3.0.
>
> In recent kernel (version 3.16.0-rc4), the code for the two mentioned
> functions looks as below -
>
> /**
> * cpuidle_install_idle_handler - installs the cpuidle idle loop handler
> */
> void cpuidle_install_idle_handler(void)
> {
>         if (enabled_devices) {
>                 /* Make sure all changes finished before we switch to
> new idle */
>                 smp_wmb();
>                 initialized = 1;
>         }
> }
>
> /**
> * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop
> handler
> */
> void cpuidle_uninstall_idle_handler(void)
> {
>         if (enabled_devices) {
>                 initialized = 0;
>                 kick_all_cpus_sync();
>         }
> }
>
>
> That is the source of confusion. There is no pm_idle handler installed
> (or uninstalled) anymore.
>
> --
> Thanks,
> -Meraj
>
>
>
>
>
>
> On Tue, Jul 22, 2014 at 4:54 PM, Mulyadi Santosa
> <mulyadi.santosa at gmail.com> wrote:
>> On Fri, Jul 18, 2014 at 11:07 PM, Mohammad Merajul Islam Molla
>> <meraj.enigma at gmail.com> wrote:
>>> Hello,
>>>
>>> In drivers/cpuidle/cpuidle.c, there are two functions
>>> cpuidle_install_idle_handler & cpuidle_uninstall_idle_handler. The
>>> names seem confusing to me as they don't install any handler, rather
>>> set 'initialized'  variable to 1/0.
>>>
>>> In v3.0 kernel, these functions used to look as below where they
>>> installed and uninstalled some handler function  -
>>>
>>> void cpuidle_install_idle_handler(void)
>>> 123 {
>>> 124         if (enabled_devices && (pm_idle != cpuidle_idle_call)) {
>>> 125                 /* Make sure all changes finished before we switch
>>> to new idle */
>>> 126                 smp_wmb();
>>> 127                 pm_idle = cpuidle_idle_call;
>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>> pm_idle is the callback handler, and it is assigned to
>> cpuidle_idle_call. I think this what it means by "install"
>>
>>
>> --
>> regards,
>>
>> Mulyadi Santosa
>> Freelance Linux trainer and consultant
>>
>> blog: the-hydra.blogspot.com
>> training: mulyaditraining.blogspot.com
>
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