linux-kernel - Re: [PATCH v2] vmpressure: implement strict mode

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: <20130627150231.2bc00e3efcd426c4beef894c@linux-foundation.org>
Date:	Thu, 27 Jun 2013 15:02:31 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Luiz Capitulino <lcapitulino@...hat.com>
Cc:	linux-mm@...ck.org, linux-kernel@...r.kernel.org, mhocko@...e.cz,
	minchan@...nel.org, anton@...msg.org, kmpark@...radead.org,
	hyunhee.kim@...sung.com
Subject: Re: [PATCH v2] vmpressure: implement strict mode

On Wed, 26 Jun 2013 23:17:12 -0400 Luiz Capitulino <lcapitulino@...hat.com> wrote:

> Currently, an eventfd is notified for the level it's registered for
> _plus_ higher levels.
> 
> This is a problem if an application wants to implement different
> actions for different levels. For example, an application might want
> to release 10% of its cache on level low, 50% on medium and 100% on
> critical. To do this, an application has to register a different
> eventfd for each pressure level. However, fd low is always going to
> be notified and and all fds are going to be notified on level critical.
> 
> Strict mode solves this problem by strictly notifiying an eventfd
> for the pressure level it registered for. This new mode is optional,
> by default we still notify eventfds on higher levels too.
> 

It didn't take long for this simple interface to start getting ugly :(
And having the fd operate in different modes is ugly.

Can we instead pass the level in the event payload?

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/