linux-kernel - Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8)

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: <1274971317.27810.5070.camel@twins>
Date:	Thu, 27 May 2010 16:41:57 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Matthew Garrett <mjg59@...f.ucam.org>
Cc:	Alan Cox <alan@...rguk.ukuu.org.uk>,
	Arve Hjønnevåg <arve@...roid.com>,
	Florian Mickler <florian@...kler.org>,
	Vitaly Wool <vitalywool@...il.com>,
	LKML <linux-kernel@...r.kernel.org>, felipe.balbi@...ia.com,
	Linux OMAP Mailing List <linux-omap@...r.kernel.org>,
	Linux PM <linux-pm@...ts.linux-foundation.org>
Subject: Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8)

On Thu, 2010-05-27 at 15:35 +0100, Matthew Garrett wrote:
> On Thu, May 27, 2010 at 04:28:51PM +0200, Peter Zijlstra wrote:
> > On Thu, 2010-05-27 at 15:06 +0100, Matthew Garrett wrote:
> > > one way which indicates to the scheduler that tasks in TASK_RUNNING 
> > > should be scheduled, and when the session is idle we set the flag the 
> > > other way and all processes in that cgroup get shifted to 
> > > TASK_INTERRUPTIBLE or something.
> > 
> > What's wrong with simply making the phone beep loudly and displaying:
> > bouncing cows is preventing your phone from sleeping!
> 
> Well, primarily that it's possible to design an implementation where it 
> *doesn't* prevent your phone froms sleeping, but also because a given 
> application may justifiably be preventing your phone from sleeping for a 
> short while. What threshold do you use to determine the difference?

Whatever you want, why would the kernel care?

You can create a whole resource management layer in userspace, with
different privilidge/trust levels. Trusted apps may wake more than
untrusted apps. Who cares.

The thing is, you can easily detect what keeps your cpu from idling.
What you do about it a pure userspace solution.

You can use the QoS stuff to give hints, like don't wake me more than 5
times a minute, if with those hints an app still doesn't meet whatever
criteria are suitable for the current mode, yell at it. Or adjust its
QoS parameters for it.

Heck, for all I care, simply SIGKILL the thing and report it once the
user starts looking at his screen again.
--
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/