[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1245090608.13761.19349.camel@twins>
Date: Mon, 15 Jun 2009 20:30:08 +0200
From: Peter Zijlstra <peterz@...radead.org>
To: Ingo Molnar <mingo@...e.hu>
Cc: Hugh Dickins <hugh.dickins@...cali.co.uk>,
linux-kernel@...r.kernel.org, mingo@...hat.com, hpa@...or.com,
paulus@...ba.org, acme@...hat.com, efault@....de, npiggin@...e.de,
tglx@...utronix.de, linux-tip-commits@...r.kernel.org,
Linus Torvalds <torvalds@...ux-foundation.org>,
Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [tip:perfcounters/core] x86: Add NMI types for kmap_atomic
On Mon, 2009-06-15 at 20:25 +0200, Ingo Molnar wrote:
> * Peter Zijlstra <peterz@...radead.org> wrote:
> but ... look at the APIs i propose above. We dont need _any_
> 'types'.
>
> That type enumeration is basically an open-coded allocator. If we do
> a _real_ allocator (a balanced stack of atomic kmaps) we dont need
> any of those indices, and all the potential for mismatch goes away
> as well - a stack nests trivially with IRQ and NMI and arbitrary
> other contexts.
You want types because:
- they encode the intent, and can be verified
- they help keep track of the max nesting depth
In the proposed implementation all type code basically falls away no !
CONFIG_DEBUG_VM, but is kept around for robustness.
--
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