linux-kernel - Re: [PATCH v1 1/4] mm/mempolicy: skip nodemask intersect check for 'interleave' when oom

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20210527132252.GA43221@shbuild999.sh.intel.com>
Date:   Thu, 27 May 2021 21:22:52 +0800
From:   Feng Tang <feng.tang@...el.com>
To:     Michal Hocko <mhocko@...e.com>
Cc:     linux-mm@...ck.org, Andrew Morton <akpm@...ux-foundation.org>,
        David Rientjes <rientjes@...gle.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Ben Widawsky <ben.widawsky@...el.com>,
        linux-kernel@...r.kernel.org,
        Andrea Arcangeli <aarcange@...hat.com>,
        Mel Gorman <mgorman@...hsingularity.net>,
        Mike Kravetz <mike.kravetz@...cle.com>,
        Randy Dunlap <rdunlap@...radead.org>,
        Vlastimil Babka <vbabka@...e.cz>,
        Andi Kleen <ak@...ux.intel.com>,
        Dan Williams <dan.j.williams@...el.com>, ying.huang@...el.com
Subject: Re: [PATCH v1 1/4] mm/mempolicy: skip nodemask intersect check for
 'interleave' when oom

On Thu, May 27, 2021 at 03:15:04PM +0200, Michal Hocko wrote:
> On Thu 27-05-21 21:05:01, Feng Tang wrote:
> > On Thu, May 27, 2021 at 09:30:00AM +0200, Michal Hocko wrote:
> [...]
> > > Until now this was not a real problem even for OOM context because
> > > alloc_page_interleave is always used for the interleaving policy
> > > and that one doesn't use any node mask so the code is not really
> > > exercised. With your MPOL_PREFERRED this would no longer be the case.
> >  
> > Given the 'interleave' task may have memory allocated from all nodes,
> > shouldn't the mempolicy_nodemask_intersects() return true for 'interleave'?
> > or I'm still missing something?
> 
> Well, if you go with the renaming then it should be quite obvious that
> any policies which are not a hard binding should return true. 

Ok, will do the rename. thanks for clarifying!

- Feng

> -- 
> Michal Hocko
> SUSE Labs