On Fri, May 26, 2017 at 10:13 AM, Eric Dumazet <eduma...@google.com> wrote:
> On Fri, May 26, 2017 at 10:08 AM, Cong Wang <xiyou.wangc...@gmail.com> wrote:
>> On Thu, May 25, 2017 at 2:27 PM, Eric Dumazet <eric.duma...@gmail.com> wrote:
>
>> Just one nit below.
>>
>>> -const u32 dst_default_metrics[RTAX_MAX + 1] = {
>>> +const struct dst_metrics dst_default_metrics = {
>>> /* This initializer is needed to force linker to place this variable
>>> * into const section. Otherwise it might end into bss section.
>>> * We really want to avoid false sharing on this variable, and catch
>>> * any writes on it.
>>> */
>>> - [RTAX_MAX] = 0xdeadbeef,
>>> + .refcnt = ATOMIC_INIT(1),
>>> };
>>
>> The code comment above is no longer needed since
>> we have to initialize refcnt to 1, instead of merely for const
>> section.
>
> I believe the comment is still needed, because normally we make sure
> dst_default_metrics.refcnt is never touched (incremened nor
> decremented)
>
> So its value should not really matter ?
Oh, you're right, we always have the check on != &dst_default_metrics.
>
> I found that ATOMIC_INIT(1) was less ugly than the 0xdeadbeef
Of course.
