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From: Thomas Gleixner <tglx@linutronix.de>
To: psodagud@codeaurora.org
Cc: john.stultz@linaro.org, sboyd@kernel.org, tj@kernel.org,
	linux-kernel@vger.kernel.org, saravanak@google.com,
	pkondeti@codeaurora.org, Joonwoo Park <joonwoop@codeaurora.org>
Subject: Re: [PATCH v3 1/2] timer: make deferrable cpu unbound timers really not bound to a cpu
Date: Wed, 13 May 2020 22:28:20 +0200	[thread overview]
Message-ID: <87d0771swr.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <dbc01cd27346bb465744b93ece2b6362@codeaurora.org>

psodagud@codeaurora.org writes:
> On 2020-05-06 06:28, Thomas Gleixner wrote:
>>>  #ifdef CONFIG_SMP
>>> +struct timer_base timer_base_deferrable;
>>>  unsigned int sysctl_timer_migration = 1;
>>> 
>>>  DEFINE_STATIC_KEY_FALSE(timers_migration_enabled);
>>> @@ -841,8 +842,14 @@ static inline struct timer_base 
>>> *get_timer_cpu_base(u32 tflags, u32 cpu)
>>>  	 * If the timer is deferrable and NO_HZ_COMMON is set then we need
>>>  	 * to use the deferrable base.
>>>  	 */
>>> -	if (IS_ENABLED(CONFIG_NO_HZ_COMMON) && (tflags & TIMER_DEFERRABLE))
>>> -		base = per_cpu_ptr(&timer_bases[BASE_DEF], cpu);
>>> +	if (IS_ENABLED(CONFIG_NO_HZ_COMMON) && (tflags & TIMER_DEFERRABLE)) 
>>> {
>>> +#ifdef CONFIG_SMP
>>> +		base = &timer_base_deferrable;
>>> +#endif
>> 
>> There are definitely smarter ways of solving this than sprinkling
>> #ifdef's around the code.
>
> I am able to understand all other comments and I will address all those 
> comments in the next patch set.
> It is not clear to me how to avoid #ifdef's in this case. Could you 
> please share an example here?

The answer is further down already:
 
>> Stub functions exist to avoid this unreadable #ifdef garbage.


  reply	other threads:[~2020-05-13 20:28 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-02 18:28 [PATCH v3 0/2] timer: make deferrable cpu unbound timers really not bound to a cpu Prasad Sodagudi
2020-05-02 18:28 ` [PATCH v3 1/2] " Prasad Sodagudi
2020-05-04 18:11   ` kbuild test robot
2020-05-05  0:08   ` kbuild test robot
2020-05-06 13:28   ` Thomas Gleixner
2020-05-13 19:53     ` psodagud
2020-05-13 20:28       ` Thomas Gleixner [this message]
2020-05-13 20:55         ` psodagud
2020-05-13 21:34           ` Thomas Gleixner
2020-05-02 18:28 ` [PATCH v3 2/2] sched: Add a check for cpu unbound deferrable timers Prasad Sodagudi
2020-05-04 19:11   ` kbuild test robot
2020-05-06 14:03   ` Thomas Gleixner

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