From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <peterz@infradead.org>
Subject: Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8)
Date: Fri, 28 May 2010 20:16:20 +0200
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To: Zygo Blaxell <vger-linux-omap-esightcorp@mailtoo.hungrycats.org>
Cc: Brian Swetland <swetland@google.com>, Alan Cox <alan@lxorguk.ukuu.org.uk>, Matthew Garrett <mjg59@srcf.ucam.org>, Igor Stoppa <igor.stoppa@nokia.com>, tytso@mit.edu, LKML <linux-kernel@vger.kernel.org>, Florian Mickler <florian@mickler.org>, Linux PM <linux-pm@lists.linux-foundation.org>, Thomas Gleixner <tglx@linutronix.de>, Linux OMAP Mailing List <linux-omap@vger.kernel.org>, "Balbi Felipe (Nokia-D/Helsinki)" <felipe.balbi@nokia.com>

On Fri, 2010-05-28 at 13:27 -0400, Zygo Blaxell wrote:
> From my reading of this thread, there's a lot of overlap between
> suspendblockers and constraints.  Many use cases are served equally
> well with one or the other, 

If using suspend-blockers, 

Please explain to me how:

- I will avoid the cpu going into some idle state for which the wakeup
latency is larger than my RT app fancies?

- to avoid some tasks from being serviced by the filesystems whilst
others are? (ionice on steroids).

- does my sporadic task (with strict bandwidth budget) not suffer
bandwidth inversion?


suspend blockers do a bit of each of that, but none of it in a usable
fashion.