linux-kernel - Re: mm: 5.16 regression: reclaim_throttle leads to stall in near-OOM conditions

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: <20211124210320.591dd883@mail.inbox.lv>
Date:   Wed, 24 Nov 2021 21:03:20 +0900
From:   Alexey Avramov <hakavlad@...ox.lv>
To:     Mel Gorman <mgorman@...hsingularity.net>
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org, mhocko@...e.com,
        vbabka@...e.cz, neilb@...e.de, akpm@...ux-foundation.org,
        corbet@....net, riel@...riel.com, hannes@...xchg.org,
        david@...morbit.com, willy@...radead.org, hdanton@...a.com,
        penguin-kernel@...ove.sakura.ne.jp, oleksandr@...alenko.name,
        kernel@...mod.org, michael@...haellarabel.com, aros@....com,
        hakavlad@...il.com
Subject: Re: mm: 5.16 regression: reclaim_throttle leads to stall in
 near-OOM conditions

>but can you test this?

I have already tested different parameters, and 
found that even zero timeout is unsatisfactory.

The introduction of reclaim_throttle() itself 
dramatically worsens the stall in near-OOM.

More info: 
https://lore.kernel.org/lkml/20211124011954.7cab9bb4@mail.inbox.lv/

What test else I should perform?

Okay, on one side of the scale is the use of the CPU, on the other 
side is the risk of stall.

My dissatisfaction is caused by the fact that the scale has now 
tipped sharply in favor of stall.
Although even before this change, users complained about the inability 
to wait for OOM:
https://lore.kernel.org/lkml/d9802b6a-949b-b327-c4a6-3dbca485ec20@gmx.com/