From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Livio Soares <livio@eecg.toronto.edu>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: [PATCH] Fix performance monitor exception in 2.6.20-series
Date: Sun, 14 Jan 2007 11:29:04 +1100 [thread overview]
Message-ID: <1168734544.5011.78.camel@localhost.localdomain> (raw)
In-Reply-To: <20070113154029.GA32292@eecg.toronto.edu>
> IMHO, option #1 is very nice, as long as the PMU interrupt handler behaves
> itself. One reason option #1 is desirable is, with PC-sampling, we are now able
> to sample regions _inside_ interrupt-disabled sections (assuming an actual
> external interrupt hasn't really occured yet). Before, with hardware disabling
> of interrupts, the PMU exceptions were necessarily delivered outside of
> interrupt disabled sections.
>
> Anyways, does anyone see a problem with the following patch?
Well, are you absolutely sure that nothing will break as a result of
having a PMU interrupt happening right when it's not expected to ?
You are basically turning the PMU interrupt into an NMI... I'm not sure
how safe that is.
Ben.
next prev parent reply other threads:[~2007-01-14 0:29 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-01-13 15:40 [PATCH] Fix performance monitor exception in 2.6.20-series Livio Soares
2007-01-14 0:29 ` Benjamin Herrenschmidt [this message]
2007-01-14 0:39 ` Segher Boessenkool
2007-01-14 17:56 ` Livio Soares
2007-01-15 2:40 ` David Woodhouse
2007-01-15 2:53 ` Paul Mackerras
2007-01-15 3:14 ` David Woodhouse
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