Re: [RFC v2] mm: add page preemption

[David Hildenbrand]

On 29.10.19 13:30, Hillf Danton wrote:
> Date: Tue, 29 Oct 2019 09:41:53 +0100 Michal Hocko wrote:
> > As already raised in the review of v1. There is no real life usecase
> > described in the changelog.
>
> No feature, no user; no user, no workloads.
> No linux-6.x released, no 6.x users.
> Are you going to be one of the users of linux-6.0?
>
> Even though, I see a use case over there at
> https://lore.kernel.org/lkml/20191023120452.GN754@xxxxxxxxxxxxxx/
>
> That thread terminated because of preemption, showing us how useful
> preemption might be in real life.
>
> > I have also expressed concerns about how
> > such a reclaim would work in the first place
>
> Based on what?
>
> > (priority inversion,
>
> No prio inversion will happen after introducing prio to global reclaim.
>
> > expensive reclaim etc.).
>
> No cost, no earn.

Side note: You should really have a look what your mail client is 
messing up here. E.g., the reply from Michal correctly had

Message-ID: <20191029084153.GD31513@xxxxxxxxxxxxxx>
References: <20191026112808.14268-1-hdanton@xxxxxxxx>
In-Reply-To: <20191026112808.14268-1-hdanton@xxxxxxxx>

Once you reply to that, you have

Message-Id: <20191029123058.19060-1-hdanton@xxxxxxxx>
In-Reply-To: <20191026112808.14268-1-hdanton@xxxxxxxx>
References:

Instead of

Message-Id: <20191029123058.19060-1-hdanton@xxxxxxxx>
In-Reply-To: <20191029084153.GD31513@xxxxxxxxxxxxxx>
References: <20191029084153.GD31513@xxxxxxxxxxxxxx>

Which flattens the whole thread hierarchy. Nasty. Please fix that.

--

Thanks,

David / dhildenb