linux-kernel - Re: [RFC PATCH v2 0/3] mm: mempolicy: Multi-tier weighted interleaving

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>] [day] [month] [year] [list]

Message-ID: <ZTfjqoEZXQWs/rxV@memverge.com>
Date:   Tue, 24 Oct 2023 11:32:58 -0400
From:   Gregory Price <gregory.price@...verge.com>
To:     "Huang, Ying" <ying.huang@...el.com>
Cc:     Gregory Price <gourry.memverge@...il.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, linux-cxl@...r.kernel.org,
        akpm@...ux-foundation.org, sthanneeru@...ron.com,
        "Aneesh Kumar K.V" <aneesh.kumar@...ux.ibm.com>,
        Wei Xu <weixugc@...gle.com>,
        Alistair Popple <apopple@...dia.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Johannes Weiner <hannes@...xchg.org>,
        Jonathan Cameron <Jonathan.Cameron@...wei.com>,
        Michal Hocko <mhocko@...nel.org>,
        Tim Chen <tim.c.chen@...el.com>, Yang Shi <shy828301@...il.com>
Subject: Re: [RFC PATCH v2 0/3] mm: mempolicy: Multi-tier weighted
 interleaving

On Mon, Oct 23, 2023 at 10:09:56AM +0800, Huang, Ying wrote:
> Gregory Price <gregory.price@...verge.com> writes:
> 
> > Depends.  if a user explicitly launches with `numactl --cpunodebind=0`
> > then yes, you can force a task (and all its children) to run on node0.
> 
> IIUC, in your example, the `numactl` command line will be
> 
>   numactl --cpunodebind=0 --weighted-interleave=0,1,2,3
> 
> That is, the CPU is restricted to node 0, while memory is distributed to
> all nodes.  This doesn't sound like reasonable for me.
> 

It being reasonable isn't really relevant. You can do this today with
normal interleave:

numactl --cpunodebind=0 --interleave=0,1,2,3

The only difference between this method and that is the application of
weights.  Doesn't seem reasonable to lock users out of doing it.

> 
> IMHO, we should keep thing as simple as possible, only add complexity if
> necessary.
>

Not allowing it is more complicated than allowing it.