lkml.org 
[lkml]   [2016]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] usb:serial: Add Fintek F81532/534 driver
From
Date
Hi Alan,

One Thousand Gnomes 於 2016/7/29 下午 08:48 寫道:
> O
>> +static int f81534_set_normal_register(struct usb_device *dev, u16 reg, u8 data)
>> +{
>> + size_t count = F81534_USB_MAX_RETRY;
>> + int status;
>> + u8 *tmp;
>> +
>> + tmp = kmalloc(sizeof(u8), GFP_KERNEL);
>> + if (!tmp)
>> + return -ENOMEM;
>
> You end up doing huge numbers of tiny allocation and frees in some of the
> code paths. I think it would be better to allocate them at a higher level
> as they are not that cheap on CPU time.
>
>> +static int f81534_read_data(struct usb_serial *usbserial, u32 address,
>> + size_t size, unsigned char *buf)
>> +{
>
> Is a particularly good example - you do 4 mallocs plus two per byte of
> data.
>

I'll re-factor the newest V9 patch with your suggestion. To malloc a
byte within usb_serial privates, and make a mutex to protect it.

I'll send it as V10 when I tested it.

Thanks for your suggestion.
--
With Best Regards,
Peter Hong

\
 
 \ /
  Last update: 2016-08-04 09:01    [W:0.050 / U:0.488 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site