Re: [PATCH] mmc: change to use kmalloc

[Peter Hurley <peter@hurleysoftware.com>]

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