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From: Matt Mackall <mpm@selenic.com>
To: Chris Peterson <cpeterso@cpeterso.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [resend] drivers/net: remove network drivers' last few uses of IRQF_SAMPLE_RANDOM
Date: Wed, 13 May 2009 09:25:38 -0500	[thread overview]
Message-ID: <20090513142535.GB31071@waste.org> (raw)
In-Reply-To: <a24804730905130017t545b7645x71ab7a1c8ab4af78@mail.gmail.com>

On Wed, May 13, 2009 at 12:17:29AM -0700, Chris Peterson wrote:
> > The future model will continue to sample network
> > devices on theory that they -might- be less than 100% observable and
> > that can only increase our total (unmeasurable) amount of entropy.
> 
> That sounds reasonable to me. So should all net drivers now specify
> IRQF_SAMPLE_RANDOM?
> 
> Or even simpler: could request_irq() assume IRQF_SAMPLE_RANDOM for any
> interrupt that is not (say) IRQF_IRQPOLL or IRQF_PERCPU?

Maybe. We don't want IRQ latency to suffer. So before we turn on
sampling of -all- sources, we need to make sampling lighter weight and
we need a way to say 'we have enough' so that we're not consuming CPU
when our pools are 'full'. We could turn it on now and rely on the
current trickle logic, but it's nice to have the water main off when
doing significant plumbing.

-- 
Mathematics is the supreme nostalgia of our time.

  reply	other threads:[~2009-05-13 14:25 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-13  5:34 Chris Peterson
2009-05-13  6:08 ` Matt Mackall
2009-05-13  7:17   ` Chris Peterson
2009-05-13 14:25     ` Matt Mackall [this message]
2009-05-13 19:39       ` Jeff Garzik
2009-05-13 19:55         ` Matt Mackall
  -- strict thread matches above, loose matches on Subject: below --
2008-06-14  5:48 Chris Peterson
2008-06-14  9:43 ` Jeff Garzik
     [not found] <ayJOq-3EJ-15@gated-at.bofh.it>
2008-05-29 12:41 ` Martin Wilck
2008-05-29  6:23 Chris Peterson
2008-05-29 10:49 ` Alan Cox

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