linux-kernel - Re: [RFD] Automatic suspend

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: <200902272158.31784.rjw@sisk.pl>
Date:	Fri, 27 Feb 2009 21:58:29 +0100
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	Alan Stern <stern@...land.harvard.edu>
Cc:	Pavel Machek <pavel@....cz>, Oliver Neukum <oliver@...kum.org>,
	"Arve Hj?nnev?g" <arve@...roid.com>,
	"Woodruff, Richard" <r-woodruff2@...com>,
	Arjan van de Ven <arjan@...radead.org>,
	Kyle Moffett <kyle@...fetthome.net>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	pm list <linux-pm@...ts.linux-foundation.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Nigel Cunningham <nigel@...el.suspend2.net>,
	Matthew Garrett <mjg59@...f.ucam.org>,
	mark gross <mgross@...ux.intel.com>,
	Uli Luckas <u.luckas@...d.de>,
	Igor Stoppa <igor.stoppa@...ia.com>,
	Brian Swetland <swetland@...gle.com>,
	Len Brown <lenb@...nel.org>
Subject: Re: [RFD] Automatic suspend

On Friday 27 February 2009, Alan Stern wrote:
> On Fri, 27 Feb 2009, Pavel Machek wrote:
> 
> > 
> > > To summarize, we can:
> > > * Use a refcount such that automatic suspend will only be possible if it's
> > >   equal to zero (but that need not be the only criterion).
> > > * Use a per-device flag in dev_pm_info that will be set whenever the device
> > >   driver increases the refcount and unset whenever the driver decreases the
> > >   refcount.
> > > * Use a per-process flag that will be set whenever the process increases the
> > >   refcount and unset whenever the process decreases the refcount.
> > 
> > Yes, that sounds sane, and that's how reasonable wakelock
> > implementation should look like.
> 
> One small point: If you add a per-device flag and a per-process flag as 
> described above, then drivers and processes must not acquire nested 
> references.
> 
> Obviously this is fixable, but it's worth mentioning...

Yes, it's important to remeber IMO.

Thanks,
Rafael
--
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/