* [PATCH] mmc: change to use kmalloc
@ 2015-11-11 4:23 yalin wang
2015-11-11 17:02 ` Alim Akhtar
0 siblings, 1 reply; 5+ messages in thread
From: yalin wang @ 2015-11-11 4:23 UTC (permalink / raw)
To: ulf.hansson, adrian.hunter, ben, jh80.chung, asaf.vertz, tklauser,
jonathanh, JBottomley, grundler, linux-mmc, linux-kernel
Cc: yalin wang
Use kmalloc instead of kzalloc, zero the memory is not needed.
Signed-off-by: yalin wang <yalin.wang2010@gmail.com>
---
drivers/mmc/card/block.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 23b6c8e..975cd3e 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -365,7 +365,7 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user(
if (!idata->buf_bytes)
return idata;
- idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL);
+ idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL);
if (!idata->buf) {
err = -ENOMEM;
goto idata_err;
--
1.9.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] mmc: change to use kmalloc
2015-11-11 4:23 [PATCH] mmc: change to use kmalloc yalin wang
@ 2015-11-11 17:02 ` Alim Akhtar
2015-11-11 21:17 ` Peter Hurley
0 siblings, 1 reply; 5+ messages in thread
From: Alim Akhtar @ 2015-11-11 17:02 UTC (permalink / raw)
To: yalin wang
Cc: Ulf Hansson, Adrian Hunter, ben, Jaehoon Chung, asaf.vertz,
tklauser, jonathanh, James E.J. Bottomley, Grant Grundler,
linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org
Hi Yalin,
On Wed, Nov 11, 2015 at 9:53 AM, yalin wang <yalin.wang2010@gmail.com> wrote:
> Use kmalloc instead of kzalloc, zero the memory is not needed.
>
why you want to do this? what problem you faces, and how this resolves the same?
> Signed-off-by: yalin wang <yalin.wang2010@gmail.com>
> ---
> drivers/mmc/card/block.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 23b6c8e..975cd3e 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -365,7 +365,7 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user(
> if (!idata->buf_bytes)
> return idata;
>
> - idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL);
> + idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL);
> if (!idata->buf) {
> err = -ENOMEM;
> goto idata_err;
> --
> 1.9.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Regards,
Alim
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] mmc: change to use kmalloc
2015-11-11 17:02 ` Alim Akhtar
@ 2015-11-11 21:17 ` Peter Hurley
2015-11-11 21:57 ` Andy Shevchenko
0 siblings, 1 reply; 5+ messages in thread
From: Peter Hurley @ 2015-11-11 21:17 UTC (permalink / raw)
To: Alim Akhtar, yalin wang
Cc: Ulf Hansson, Adrian Hunter, ben, Jaehoon Chung, asaf.vertz,
tklauser, jonathanh, James E.J. Bottomley, Grant Grundler,
linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org
On 11/11/2015 12:02 PM, Alim Akhtar wrote:
> Hi Yalin,
>
> On Wed, Nov 11, 2015 at 9:53 AM, yalin wang <yalin.wang2010@gmail.com> wrote:
>> Use kmalloc instead of kzalloc, zero the memory is not needed.
>>
> why you want to do this? what problem you faces, and how this resolves the same?
The patch fixes an inefficiency: explicitly zeroing memory that is then
immediately overwritten 6 lines below is wasteful.
Regards,
Peter Hurley
>> Signed-off-by: yalin wang <yalin.wang2010@gmail.com>
>> ---
>> drivers/mmc/card/block.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
>> index 23b6c8e..975cd3e 100644
>> --- a/drivers/mmc/card/block.c
>> +++ b/drivers/mmc/card/block.c
>> @@ -365,7 +365,7 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user(
>> if (!idata->buf_bytes)
>> return idata;
>>
>> - idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL);
>> + idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL);
>> if (!idata->buf) {
>> err = -ENOMEM;
>> goto idata_err;
>> --
>> 1.9.1
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] mmc: change to use kmalloc
2015-11-11 21:17 ` Peter Hurley
@ 2015-11-11 21:57 ` Andy Shevchenko
2015-11-12 11:27 ` yalin wang
0 siblings, 1 reply; 5+ messages in thread
From: Andy Shevchenko @ 2015-11-11 21:57 UTC (permalink / raw)
To: Peter Hurley
Cc: Alim Akhtar, yalin wang, Ulf Hansson, Adrian Hunter,
Ben Hutchings, Jaehoon Chung, asaf.vertz, tklauser, Jon Hunter,
James E.J. Bottomley, Grant Grundler, linux-mmc@vger.kernel.org,
linux-kernel@vger.kernel.org
On Wed, Nov 11, 2015 at 11:17 PM, Peter Hurley <peter@hurleysoftware.com> wrote:
> On 11/11/2015 12:02 PM, Alim Akhtar wrote:
>> Hi Yalin,
>>
>> On Wed, Nov 11, 2015 at 9:53 AM, yalin wang <yalin.wang2010@gmail.com> wrote:
>>> Use kmalloc instead of kzalloc, zero the memory is not needed.
>>>
>> why you want to do this? what problem you faces, and how this resolves the same?
>
> The patch fixes an inefficiency: explicitly zeroing memory that is then
> immediately overwritten 6 lines below is wasteful.
It might fix previous kzalloc as well, though better not to do since
it's error prone.
>
> Regards,
> Peter Hurley
>
>>> Signed-off-by: yalin wang <yalin.wang2010@gmail.com>
>>> ---
>>> drivers/mmc/card/block.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
>>> index 23b6c8e..975cd3e 100644
>>> --- a/drivers/mmc/card/block.c
>>> +++ b/drivers/mmc/card/block.c
>>> @@ -365,7 +365,7 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user(
>>> if (!idata->buf_bytes)
>>> return idata;
>>>
>>> - idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL);
>>> + idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL);
>>> if (!idata->buf) {
>>> err = -ENOMEM;
>>> goto idata_err;
>>> --
>>> 1.9.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] mmc: change to use kmalloc
2015-11-11 21:57 ` Andy Shevchenko
@ 2015-11-12 11:27 ` yalin wang
0 siblings, 0 replies; 5+ messages in thread
From: yalin wang @ 2015-11-12 11:27 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Peter Hurley, Alim Akhtar, Ulf Hansson, Adrian Hunter,
Ben Hutchings, Jaehoon Chung, asaf.vertz, Tobias Klauser,
Jon Hunter, James E.J. Bottomley, Grant Grundler,
linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org
> On Nov 12, 2015, at 05:57, Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
>
> On Wed, Nov 11, 2015 at 11:17 PM, Peter Hurley <peter@hurleysoftware.com> wrote:
>> On 11/11/2015 12:02 PM, Alim Akhtar wrote:
>>> Hi Yalin,
>>>
>>> On Wed, Nov 11, 2015 at 9:53 AM, yalin wang <yalin.wang2010@gmail.com> wrote:
>>>> Use kmalloc instead of kzalloc, zero the memory is not needed.
>>>>
>>> why you want to do this? what problem you faces, and how this resolves the same?
>>
>> The patch fixes an inefficiency: explicitly zeroing memory that is then
>> immediately overwritten 6 lines below is wasteful.
>
> It might fix previous kzalloc as well, though better not to do since
> it's error prone.
>
yeah, i will send a new patch ,
>>
>> Regards,
>> Peter Hurley
>>
>>>> Signed-off-by: yalin wang <yalin.wang2010@gmail.com>
>>>> ---
>>>> drivers/mmc/card/block.c | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
>>>> index 23b6c8e..975cd3e 100644
>>>> --- a/drivers/mmc/card/block.c
>>>> +++ b/drivers/mmc/card/block.c
>>>> @@ -365,7 +365,7 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user(
>>>> if (!idata->buf_bytes)
>>>> return idata;
>>>>
>>>> - idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL);
>>>> + idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL);
>>>> if (!idata->buf) {
>>>> err = -ENOMEM;
>>>> goto idata_err;
>>>> --
>>>> 1.9.1
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>> Please read the FAQ at http://www.tux.org/lkml/
>
>
>
> --
> With Best Regards,
> Andy Shevchenko
^ permalink raw reply [flat|nested] 5+ messages in thread
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2015-11-11 4:23 [PATCH] mmc: change to use kmalloc yalin wang
2015-11-11 17:02 ` Alim Akhtar
2015-11-11 21:17 ` Peter Hurley
2015-11-11 21:57 ` Andy Shevchenko
2015-11-12 11:27 ` yalin wang
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