From: Chunhe Lan <b25806@freescale.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Chunhe Lan <Chunhe.Lan@freescale.com>,
linux-mmc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
kumar.gala@freescale.com, cjb@laptop.org,
Kumar Gala <galak@kernel.crashing.org>
Subject: Re: [PATCH v3 1/2] mmc: Move mmc_delay() to include/linux/mmc/core.h
Date: Mon, 24 Sep 2012 11:20:58 -0400 [thread overview]
Message-ID: <50607A5A.3060103@freescale.com> (raw)
In-Reply-To: <201209211233.54545.arnd@arndb.de>
On 09/21/2012 08:33 AM, Arnd Bergmann wrote:
> On Friday 21 September 2012, Chunhe Lan wrote:
>> On 08/10/2012 09:27 AM, Arnd Bergmann wrote:
>>> On Friday 10 August 2012, Chunhe Lan wrote:
>>>
>>> cond_resched();
>>> mdelay(ms);
>>>
>>> sets off alarm bells, and I would always replace that with msleep().
>> I think that it does not replace with msleep().
>> When the time of sleep is very short, program should not been scheduled
>> in the context. Because it expends the more time.
>>
> A time measured in miliseconds is never "very short" for the scheduler,
> a lot of things can happen during that time span. The code I quoted
> also does not care too much about accuracy, otherwise it would adapt
> the time in the mdelay based on whether the cond_resched() actually
> schedules to another thread.
OK. As you have mentioned, it would been modified to such:
static inline void mmc_delay(unsigned int ms)
{
if (ms < 1000 / HZ) {
cond_resched();
msleep(ms);
} else {
msleep(ms);
}
}
OR such:
static inline void mmc_delay(unsigned int ms)
{
msleep(ms);
}
OR other code?
Thanks,
Chunhe
>
> Arnd
>
WARNING: multiple messages have this Message-ID (diff)
From: Chunhe Lan <b25806@freescale.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: kumar.gala@freescale.com, linux-mmc@vger.kernel.org,
cjb@laptop.org, linuxppc-dev@lists.ozlabs.org,
Chunhe Lan <Chunhe.Lan@freescale.com>
Subject: Re: [PATCH v3 1/2] mmc: Move mmc_delay() to include/linux/mmc/core.h
Date: Mon, 24 Sep 2012 11:20:58 -0400 [thread overview]
Message-ID: <50607A5A.3060103@freescale.com> (raw)
In-Reply-To: <201209211233.54545.arnd@arndb.de>
On 09/21/2012 08:33 AM, Arnd Bergmann wrote:
> On Friday 21 September 2012, Chunhe Lan wrote:
>> On 08/10/2012 09:27 AM, Arnd Bergmann wrote:
>>> On Friday 10 August 2012, Chunhe Lan wrote:
>>>
>>> cond_resched();
>>> mdelay(ms);
>>>
>>> sets off alarm bells, and I would always replace that with msleep().
>> I think that it does not replace with msleep().
>> When the time of sleep is very short, program should not been scheduled
>> in the context. Because it expends the more time.
>>
> A time measured in miliseconds is never "very short" for the scheduler,
> a lot of things can happen during that time span. The code I quoted
> also does not care too much about accuracy, otherwise it would adapt
> the time in the mdelay based on whether the cond_resched() actually
> schedules to another thread.
OK. As you have mentioned, it would been modified to such:
static inline void mmc_delay(unsigned int ms)
{
if (ms < 1000 / HZ) {
cond_resched();
msleep(ms);
} else {
msleep(ms);
}
}
OR such:
static inline void mmc_delay(unsigned int ms)
{
msleep(ms);
}
OR other code?
Thanks,
Chunhe
>
> Arnd
>
next prev parent reply other threads:[~2012-09-24 3:18 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-10 22:25 [PATCH v3 1/2] mmc: Move mmc_delay() to include/linux/mmc/core.h Chunhe Lan
2012-08-10 22:25 ` Chunhe Lan
2012-08-10 13:27 ` Arnd Bergmann
2012-08-10 13:27 ` Arnd Bergmann
2012-09-21 20:52 ` Chunhe Lan
2012-09-21 20:52 ` Chunhe Lan
2012-09-21 12:33 ` Arnd Bergmann
2012-09-21 12:33 ` Arnd Bergmann
2012-09-24 15:20 ` Chunhe Lan [this message]
2012-09-24 15:20 ` Chunhe Lan
2012-09-24 13:17 ` Arnd Bergmann
2012-09-24 13:17 ` Arnd Bergmann
2012-09-24 14:38 ` Tabi Timur-B04825
2012-09-24 14:38 ` Tabi Timur-B04825
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