[PATCH v7 1/2] Mutex: Add pthread mutex tunables

[kemi]

Hi, Rical
   Thanks for your time to review.

On 2018年07月07日 06:47, Rical Jasan wrote:
> On 07/06/2018 10:53 AM, Carlos O'Donell wrote:
>> On 07/06/2018 03:50 AM, Kemi Wang wrote:
> ...
>>> diff --git a/manual/tunables.texi b/manual/tunables.texi
>>> index be33c9f..8cdfde1 100644
>>> --- a/manual/tunables.texi
>>> +++ b/manual/tunables.texi
>>> @@ -32,6 +32,7 @@ their own namespace.
>>>  * Tunable names::  The structure of a tunable name
>>>  * Memory Allocation Tunables::  Tunables in the memory allocation subsystem
>>>  * Elision Tunables::  Tunables in elision subsystem
>>> +* Pthread Mutex Tunables:: Tunables in pthread subsystem
>>
>> POSIX Thread Tunables:: Tunables in the POSIX thread subsystem
> 
> Good.
> 

agree.

>>>  * Hardware Capability Tunables::  Tunables that modify the hardware
>>>  				  capabilities seen by @theglibc{}
>>>  @end menu
>>> @@ -281,6 +282,28 @@ of try lock attempts.
>>>  The default value of this tunable is @samp{3}.
>>>  @end deftp
>>>  
>>> +@node Pthread Mutex Tunables
>>
>> POSIX Thread Tunables
> 
> Good.
> 

Agree.

>>> +@section Pthread Mutex Tunables
>>
>> Mutex Tunables
> 
> Why call the node POSIX Thread Tunables but the section Mutex Tunables?
> 

I tend to keep the same name unless there is some other reason.

>>> +@cindex pthread mutex tunables
>>
>> thread mutex tunables
> 
> I have no objection to loading up the Concept Index.  It's meant for
> second-guessing your audience; e.g.:
> 
> @cindex pthread mutex tunables
> @cindex thread mutex tunables
> @cindex mutex tunables
> @cindex tunables thread mutex
> 

Do you suggest to include all of these Concept Index entry?

>>> +
>>> +@deftp {Tunable namespace} glibc.pthread
>>> +The behavior of pthread mutexes can be tuned to gain performance improvements
>>> +according to specific hardware capabilities and workload characteristics by
>>> +setting the following tunables in the @code{pthread} namespace:
>>
>> The behavior of POSIX threads can be tuned to gain performance improvements
>> according to specific hardware capabilities and workload characteristics by
>> setting the following tunables in the @code{pthread} namespace:
> 
> Good.
> 
>>> +@end deftp
>>> +
>>> +@deftp Tunable glibc.pthread.mutex_spin_count
>>> +The @code{glibc.pthread.mutex_spin_count} tunable sets the maximum number of times
>>> +a thread should spin on the lock before calling into the kernel to block.
>>> +Adaptive spin is used for mutexes initialized with the PTHREAD_MUTEX_ADAPTIVE_NP
>>> +GNU extension.  It affects both pthread_mutex_lock and pthread_mutex_timedlock.
>>> +
>>> +The spinning is done until either the maximum spin times is reached or
>>> +the lock is acquired.
>>> +
>>> +The default value of this tunable is @samp{100}.
>>> +@end deftp
>>> +
>>
>> OK.
> 
> I think PTHREAD_MUTEX_ADAPTIVE_NP and pthread_mutex_(timed)?lock should
> be in @code.
> 

OK. Will fold it.

> Also, "the maximum spin count is reached".
> 

OK.

>>>  @node Hardware Capability Tunables
>>>  @section Hardware Capability Tunables
>>>  @cindex hardware capability tunables
> 
> Rical
>