linux-kernel - Re: [RFC PATCH V1 1/1] sched/numa: Enhance vma scanning logic

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

Message-ID: <acf37296-485d-0281-69fd-811e7ce011b9@amd.com>
Date:   Thu, 19 Jan 2023 15:54:56 +0530
From:   Raghavendra K T <raghavendra.kt@....com>
To:     Mike Rapoport <rppt@...nel.org>
Cc:     linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Juri Lelli <juri.lelli@...hat.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
        Daniel Bristot de Oliveira <bristot@...hat.com>,
        Valentin Schneider <vschneid@...hat.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Matthew Wilcox <willy@...radead.org>,
        Vlastimil Babka <vbabka@...e.cz>,
        "Liam R . Howlett" <Liam.Howlett@...cle.com>,
        Peter Xu <peterx@...hat.com>,
        David Hildenbrand <david@...hat.com>,
        xu xin <cgel.zte@...il.com>, Yu Zhao <yuzhao@...gle.com>,
        Colin Cross <ccross@...gle.com>, Arnd Bergmann <arnd@...db.de>,
        Hugh Dickins <hughd@...gle.com>,
        Bharata B Rao <bharata@....com>,
        Disha Talreja <dishaa.talreja@....com>
Subject: Re: [RFC PATCH V1 1/1] sched/numa: Enhance vma scanning logic

On 1/19/2023 3:09 PM, Mike Rapoport wrote:
> Hi,
> 
> On Mon, Jan 16, 2023 at 07:05:34AM +0530, Raghavendra K T wrote:
>>   During the Numa scanning make sure only relevant vmas of the
>> tasks are scanned.
> 
> Please add more detailed description about what are the issues with the
> current scanning this patch aims to solve.

Thank you for the review Mike. Sure will add more detail in the patch
  commit in V2

> 
>> Logic:
>> 1) For the first two time allow unconditional scanning of vmas
>> 2) Store recent 4 unique tasks (last 8bits of PIDs) accessed the vma.
>>    False negetives in case of collison should be fine here.
> 
>           ^ negatives

will take care of this and one below

>> 3) If more than 4 pids exist assume task indeed accessed vma to
>>   to avoid false negetives
>>
>> Co-developed-by: Bharata B Rao <bharata@....com>
>> (initial patch to store pid information)
>>
>> Suggested-by: Mel Gorman <mgorman@...hsingularity.net>
>> Signed-off-by: Bharata B Rao <bharata@....com>
>> Signed-off-by: Raghavendra K T <raghavendra.kt@....com>
>> ---
[...]