Question on checpatch.pl warning -- possible unnecessary 'out of memory' message.
Dear all,
I'm fixing up my first driver (drivers/isdn/gigaset) to get some experience submitting patches. When I run checkpatch.pl on some of the code, I get the following warning:
./drivers/isdn/gigaset/capi.c:337: WARNING: Possible unnecessary 'out of memory' message
The corresponding code is:
cskb = alloc_skb(CAPI_DATA_B3_CONF_LEN, GFP_ATOMIC);
if (!cskb) {
dev_err(cs->dev, "%s: out of memory\n",
__func__);
return;
}All instances of this warning refer to usage of alloc_skb using the GFP_ATOMIC flag. Why does checkpatch show this warning? Is it not good practice to _always_ check whether allocation succeeded or not?
I hope someone can explain the nature of this warning and, if right, what it should look like.
With kind regards,
Bas Peters
Quoted 8 lines · Bas Peters <baspeters93 <at> gmail.com> writes:
I hope someone can explain the nature of this warning and, if right, what it should look like.
With kind regards,
Bas Peters
Have you googled this particular checkpath error?
You should use a preprocessor macro.
Regards
BGS
Hi Bas,
Quoted 6 lines
All instances of this warning refer to usage of
alloc_skbusing theGFP_ATOMICflag. Why does checkpatch show this warning? Is it not good practice to _always_ check whether allocation succeeded or not?I hope someone can explain the nature of this warning and, if right, what it should look like.
I suggest you to take a look at the following thread
https://lkml.org/lkml/2014/6/10/382
As a short summary to that discussion:
1. You should check the NULL pointer.
2. You shouldn't print the error.
Quoted 11 lines
With kind regards,
Bas Peters
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Leon Romanovsky | Independent Linux Consultant
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