Re: [PATCH v3 3/3] KEYS: Use kvmalloc() to better handle large buffer allocation

From: Waiman Long
Date: Sun Mar 15 2020 - 18:02:31 EST


On 3/15/20 5:52 PM, Jarkko Sakkinen wrote:
> On Fri, Mar 13, 2020 at 01:49:57PM -0400, Waiman Long wrote:
>>>> if (!tmpbuf || unlikely(ret > tmpbuflen)) {
>>>> if (unlikely(tmpbuf))
>>>> - kzfree(tmpbuf);
>>>> + __kvzfree(tmpbuf, tmpbuflen);
>>> Both kzfree() and __kvzfree() handle a NULL pointer, so there's no need for the
>>> NULL check first.
>>>
>> I would like to keep this one because of the unlikely annotation.
> What (measurable) gain does it bring anyway?

It is not a performance issue. I just want to indicate that the need to
free should not happen at all. It match the unlikely tag in the if
condition above.

Cheers,
Longman