linux-kernel - Re: [linux-pm] Re: [PATCH] Remove process freezer from suspend to RAM pathway

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]

Date:	Tue, 3 Jul 2007 13:46:56 +0200
From:	Oliver Neukum <oliver@...kum.org>
To:	Benjamin Herrenschmidt <benh@...nel.crashing.org>
Cc:	linux-pm@...ts.linux-foundation.org,
	Nigel Cunningham <nigel@...el.suspend2.net>,
	Matthew Garrett <mjg59@...f.ucam.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [linux-pm] Re: [PATCH] Remove process freezer from suspend to RAM pathway

Am Dienstag, 3. Juli 2007 schrieb Benjamin Herrenschmidt:
> On Tue, 2007-07-03 at 09:44 +0200, Oliver Neukum wrote:
> > Am Dienstag, 3. Juli 2007 schrieb Benjamin Herrenschmidt:
> > > So to summarize, the plan that makes things work with fuse is:
> > > 
> > >  - For STR, don't do the freezer thing.
> > > 
> > >  - For STD, don't sys_sync() after you froze
> > > 
> > > There might be -other- issues, but that should get you through some of
> > 
> > At the risk of repeating myself. Character device drivers are written
> > with the assumption that normal io and suspend/resume do not race
> > with each other due to the freezer.
> > What do you intend to do about that?
> 
> Ugh ... "character devices" ... that's a pretty wide statement...
> there's lots of those and very different one from the other...

That is a good summary of the problem ;-(

> Any sane device-driver will have to cope with being suspended in a
> "live" system. I've demonstrated multiple times in the past why this is
> necessary anyway, for things like dynamic power management, among
> others.

That is an interesting notion. I'd rather see device drivers reporting
their devices idle and requsting to be suspended.
But in any case it doesn't solve the problem.

	Regards
		Oliver

-
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/