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From: Andi Kleen <andi@firstfloor.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <andi@firstfloor.org>,
	linux-kernel@vger.kernel.org, mingo@kernel.org,
	eranian@google.com, tglx@linutronix.de,
	Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH] perf, x86: Fall back to vmalloc for BTS buffer allocation
Date: Wed, 10 Sep 2014 16:40:12 +0200	[thread overview]
Message-ID: <20140910144012.GI4120@two.firstfloor.org> (raw)
In-Reply-To: <20140910075722.GL6758@twins.programming.kicks-ass.net>

> We did this once, and that blew up big time.
> 
> Even now, vmalloc_fault() has a very explicit:
> 
>   WARN_ON_ONCE(in_nmi());
> 
> So this isn't going to happen until you fix that.

Good point.

We just need to call vmalloc_sync_all at allocation time,
no need to change vmalloc_fault.

-Andi



-- 
ak@linux.intel.com -- Speaking for myself only.

  reply	other threads:[~2014-09-10 14:40 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-10  0:03 [PATCH] perf, x86: Fall back to vmalloc for BTS buffer allocation Andi Kleen
2014-09-10  7:57 ` Peter Zijlstra
2014-09-10 14:40   ` Andi Kleen [this message]
2014-09-10 16:35     ` Peter Zijlstra
2014-09-10 16:58       ` Peter Zijlstra
2014-09-10 18:27         ` Andi Kleen
2014-09-10 18:52           ` Peter Zijlstra

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