[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1234459749.10603.35.camel@laptop>
Date: Thu, 12 Feb 2009 18:29:09 +0100
From: Peter Zijlstra <a.p.zijlstra@...llo.nl>
To: balbir@...ux.vnet.ibm.com
Cc: Ingo Molnar <mingo@...e.hu>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
Frederic Weisbecker <fweisbec@...il.com>,
Thomas Gleixner <tglx@...x.de>,
LKML <linux-kernel@...r.kernel.org>,
rt-users <linux-rt-users@...r.kernel.org>,
Steven Rostedt <rostedt@...dmis.org>,
Carsten Emde <ce@...g.ch>, Clark Williams <williams@...hat.com>
Subject: Re: [patch] rt: res_counter fix, v2
On Thu, 2009-02-12 at 22:28 +0530, Balbir Singh wrote:
> > _nort() will just turn them into NOPs in essence.
> >
> > The question is, are these local IRQ flags manipulations really needed
> > in this code, and if yes, why?
>
> We needed the local IRQ flags, since these counters are updated from
> page fault context and from reclaim context with lru_lock held with
> IRQ's disabled. I've been thinking about replacing the spin lock with
> seq lock, but have not gotten to it yet.
Ah, in that case we can get away with _nort I think, as both those
contexts are preemptable on -rt.
--
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/
Powered by blists - more mailing lists