linux-kernel - Re: [RFC][PATCH] PM: Force GFP_NOIO during suspend/resume (was: Re: [linux-pm] Memory allocations in .suspend became very unreliable)

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: <201001171436.29307.rjw@sisk.pl>
Date:	Sun, 17 Jan 2010 14:36:29 +0100
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	Oliver Neukum <oliver@...kum.org>
Cc:	Maxim Levitsky <maximlevitsky@...il.com>,
	linux-pm@...ts.linux-foundation.org,
	LKML <linux-kernel@...r.kernel.org>,
	"linux-mm" <linux-mm@...ck.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>
Subject: Re: [RFC][PATCH] PM: Force GFP_NOIO during suspend/resume (was: Re: [linux-pm] Memory allocations in .suspend became very unreliable)

On Sunday 17 January 2010, Rafael J. Wysocki wrote:
> On Sunday 17 January 2010, Oliver Neukum wrote:
> > Am Sonntag, 17. Januar 2010 01:38:37 schrieb Rafael J. Wysocki:
> > > > Now having said that, we've been considering a change that will turn all
> > > > GFP_KERNEL allocations into GFP_NOIO during suspend/resume, so perhaps I'll
> > > > prepare a patch to do that and let's see what people think.
> > > 
> > > If I didn't confuse anything (which is likely, because it's a bit late here
> > > now), the patch below should do the trick.  I have only checked that it doesn't
> > > break compilation, so please take it with a grain of salt.
> > > 
> > > Comments welcome.
> > 
> > I think this is a bad idea as it makes the mm subsystem behave differently
> > in the runtime and in the whole system cases.
> 
> s/runtime/suspend/ ?
> 
> Yes it will, but why exactly shouldn't it?  System suspend/resume _is_ a
> special situation anyway.

Moreover, as the Maxim's report indicates, the mm subsystem already behaves
differently during suspend/resume and this behavior is erroneous, because it
causes the system to hang.

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/