From: Saugata Das <saugata.das@linaro.org>
To: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Chris Ball <cjb@laptop.org>,
Saugata Das <saugata.das@stericsson.com>,
linux-mmc@vger.kernel.org
Subject: Re: [RFC] MMC-4.5 Context ID
Date: Mon, 6 Feb 2012 11:04:10 +0530 [thread overview]
Message-ID: <CAKLKtzcAqJVDTZFYpijicWStr7m76Quv2ic8hRZp+X_Wmd-bFQ@mail.gmail.com> (raw)
In-Reply-To: <4F2F649E.2010106@samsung.com>
On 6 February 2012 10:56, Jaehoon Chung <jh80.chung@samsung.com> wrote:
> On 02/06/2012 02:13 PM, Saugata Das wrote:
>
>> On 5 February 2012 08:15, Chris Ball <cjb@laptop.org> wrote:
>>> Hi,
>>>
>>> On Wed, Feb 01 2012, Saugata Das wrote:
>>>> From: Saugata Das <saugata.das@linaro.org>
>>>>
>>>> This patch groups the read or write transfers to eMMC in different contexts
>>>> based on the block number. Transfers to consecutive blocks are grouped to a
>>>> common context. So several small transfers combine to give performance like
>>>> a large multi block transfer.
>>>>
>>>> The patch creates a context of 1MB multiple in non-large unit mode. Reliable
>>>> mode is enabled in the context based on whether reliable write is enabled.
>>>
>>> Do you see any performance changes with this patchset? If so, can you
>>> give details?
>>
>> I do not see any performance impact (positive or negative) on the
>> sample eMMC-4.5 device which I have. This could be due to the slow
>> bridge which I use (1-bit mode at 25MHz) to connect the eMMC-4.5
>> device on micro-SD slot of 8500 platform.
>
> I think that should be increased the performance by how we select the context.
> I also didn't see any performance benefit..8-bit mode at 50Mhz.
> But i have interest for this feature
>
Thanks for the info. Perhaps the initial MMC-4.5 device samples do not
implement this command well. Yes, this feature is good to have in the
kernel. I shall wait for some more comments on the proposed
implementation before submitting the patch.
> Best Regards,
> Jaehoon Chung
>
>>
>>>
>>> Thanks,
>>>
>>> - Chris.
>>> --
>>> Chris Ball <cjb@laptop.org> <http://printf.net/>
>>> One Laptop Per Child
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
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>> --
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>>
>
>
next prev parent reply other threads:[~2012-02-06 5:34 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-01 15:27 [RFC] MMC-4.5 Context ID Saugata Das
2012-02-02 16:08 ` S, Venkatraman
2012-02-03 2:45 ` Jaehoon Chung
2012-02-03 5:48 ` Saugata Das
2012-02-03 5:47 ` Saugata Das
2012-02-05 2:45 ` Chris Ball
2012-02-06 5:13 ` Saugata Das
2012-02-06 5:26 ` Jaehoon Chung
2012-02-06 5:34 ` Saugata Das [this message]
2012-02-11 20:57 ` Chris Ball
2012-02-13 20:37 ` Saugata Das
2012-02-14 2:16 ` Jaehoon Chung
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