Re: [patch 13/20] timer: Switch to a non cascading wheel

From: Eric Dumazet
Date: Mon Jun 13 2016 - 08:47:09 EST


On Mon, Jun 13, 2016 at 5:30 AM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> On Mon, 13 Jun 2016, Peter Zijlstra wrote:
>> On Mon, Jun 13, 2016 at 08:41:00AM -0000, Thomas Gleixner wrote:
>> > +
>> > + /* Cascading, sigh... */
>>
>> So given that userspace has no influence on timer period; can't we
>> simply fail to support timers longer than 30 minutes?
>>
>> In anything really arming timers _that_ long?
>
> Unfortunately yes. Networking being one of those. Real cascading happens once
> in a blue moon, but it happens.
>

Anyway, for the more common HZ=1000 case, what would the 'limit' be ?