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Date: Mon, 18 Dec 2023 22:39:40 -0500
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Subject: Re: [PATCH 19/50] locking/mutex: split out mutex_types.h
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To: Kent Overstreet <kent.overstreet@linux.dev>
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From: Waiman Long <longman@redhat.com>
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On 12/18/23 22:37, Kent Overstreet wrote:
> On Mon, Dec 18, 2023 at 10:04:39PM -0500, Waiman Long wrote:
>> On 12/18/23 20:46, Kent Overstreet wrote:
>>> On Mon, Dec 18, 2023 at 11:53:08AM -0500, Waiman Long wrote:
>>>> On 12/15/23 22:26, Kent Overstreet wrote:
>>>>> -#include <linux/rtmutex.h>
>>>> Including rtmutex.h here means that mutex_types.h is no longer a simple
>>>> header for types only. So unless you also break out a rtmutex_types.h, it is
>>>> inconsistent.
>>> good observation, I'll have to leave it for the next round of cleanups
>>> though since the merge window is approaching and I'll have to redo all
>>> the testing.
>>>
>>>> Besides, the kernel/sched code does use mutex_lock/unlock calls quite
>>>> frequently. With this patch, mutex.h will not be directly included. I
>>>> suspect that it is indirectly included via other header files. This may be
>>>> an issue with some configurations.
>>> I've now put it through randconfig testing on every arch that debian
>>> includes a compiler for (excluding sh and xtensa, which throw internal
>>> compiler errors) and that one hasn't come up yet.
>>>
>>> could still be included indirectly though - I haven't checked for that
>>> one specifically yet.
>> If you are replacing mutex.h in include/linux/sched.h by mutex_types.h, I
>> would suggest you add mutex.h to kernel/sched/sched.h to ensure this header
>> file is included by the scheduler code.
> It already does, via mutex_api.h...

You are right. I am not aware that there is a mutex_api.h header file 
which is just an alias of mutex.h.

Cheers,
Longman