linux-kernel - Re: Idle loadavg of ~1, maybe MD related

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]

Date:	Sat, 5 Jan 2008 19:05:06 -0800
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	benh@...nel.crashing.org
Cc:	"Robin H. Johnson" <robbat2@...too.org>,
	linux-kernel@...r.kernel.org, Paul Mackerras <paulus@...ba.org>
Subject: Re: Idle loadavg of ~1, maybe MD related

On Sat, 05 Jan 2008 21:18:52 +1100 Benjamin Herrenschmidt <benh@...nel.crashing.org> wrote:

> On Sat, 2008-01-05 at 02:04 -0800, Robin H. Johnson wrote:
> > On Sat, Jan 05, 2008 at 01:30:37AM -0800, Andrew Morton wrote:
> > > >From that I'd suspect that kwindfarm is being a bad citizen.
> > > If a process is consistently stuck in D state, run
> > Windfarm.
> 
> It's an unfortunate artifact that kernel threads that do
> non-interruptible sleep are counted as load...
> 
> In the case of windfarm, it does a lot (a _LOT_) of accesses to various
> i2c busses and the SMU (the system management unit which controls the
> fans). All those are done in the form of short requests during which the
> process is doing a wait_for_completion() or similar.
> 
> I don't see a better way to do that, I think we could have good use of
> something that stops counting those in the load average...

Maybe, but we can usually work around it pretty comfortably.

If smu_set_fan() is only ever called by a kernel thread then we can simply
flip it over to using wait_for_completion_interruptible().

If smu_set_fan() is also called from user processes then things aren't so
easy...

--
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/