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]
Date:   Thu, 11 Apr 2019 09:06:00 -0700
From:   Dave Hansen <>
To:     Yang Shi <>,,,,,,,,,,,
Subject: Re: [v2 PATCH 7/9] mm: vmscan: check if the demote target node is
 contended or not

On 4/10/19 8:56 PM, Yang Shi wrote:
> When demoting to PMEM node, the target node may have memory pressure,
> then the memory pressure may cause migrate_pages() fail.
> If the failure is caused by memory pressure (i.e. returning -ENOMEM),
> tag the node with PGDAT_CONTENDED.  The tag would be cleared once the
> target node is balanced again.
> Check if the target node is PGDAT_CONTENDED or not, if it is just skip
> demotion.

This seems like an actively bad idea to me.

Why do we need an *active* note to say the node is contended?  Why isn't
just getting a failure back from migrate_pages() enough?  Have you
observed this in practice?

Powered by blists - more mailing lists