linux-kernel - Re: [RFC v2] mm: add page preemption

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 29 Oct 2019 14:26:36 +0100
From:   David Hildenbrand <david@...hat.com>
To:     Hillf Danton <hdanton@...a.com>, Michal Hocko <mhocko@...nel.org>
Cc:     linux-mm <linux-mm@...ck.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        Matthew Wilcox <willy@...radead.org>,
        Johannes Weiner <hannes@...xchg.org>,
        Shakeel Butt <shakeelb@...gle.com>,
        Minchan Kim <minchan@...nel.org>, Mel Gorman <mgorman@...e.de>,
        Vladimir Davydov <vdavydov.dev@...il.com>,
        Jan Kara <jack@...e.cz>
Subject: Re: [RFC v2] mm: add page preemption

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@dhcp22.suse.cz/
> 
> 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@...p22.suse.cz>
References: <20191026112808.14268-1-hdanton@...a.com>
In-Reply-To: <20191026112808.14268-1-hdanton@...a.com>

Once you reply to that, you have

Message-Id: <20191029123058.19060-1-hdanton@...a.com>
In-Reply-To: <20191026112808.14268-1-hdanton@...a.com>
References:

Instead of

Message-Id: <20191029123058.19060-1-hdanton@...a.com>
In-Reply-To: <20191029084153.GD31513@...p22.suse.cz>
References: <20191029084153.GD31513@...p22.suse.cz>

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

-- 

Thanks,

David / dhildenb