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From: Jeff Garzik <jeff@garzik.org>
To: Matt Mackall <mpm@selenic.com>
Cc: Chris Peterson <cpeterso@cpeterso.com>,
	linux-kernel@vger.kernel.org, NetDev <netdev@vger.kernel.org>
Subject: Re: [PATCH] [resend] drivers/net: remove network drivers' last few uses of IRQF_SAMPLE_RANDOM
Date: Wed, 13 May 2009 15:39:11 -0400	[thread overview]
Message-ID: <4A0B21DF.9050702@garzik.org> (raw)
In-Reply-To: <20090513142535.GB31071@waste.org>

Matt Mackall wrote:
> 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.

So, until such time, let's be consistent in net driver land and not 
IRQF_SAMPLE_RANDOM.

	Jeff





  reply	other threads:[~2009-05-13 19:39 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-13  5:34 [PATCH] [resend] drivers/net: remove network drivers' last few uses of IRQF_SAMPLE_RANDOM Chris Peterson
2009-05-13  6:08 ` Matt Mackall
2009-05-13  7:17   ` Chris Peterson
2009-05-13 14:25     ` Matt Mackall
2009-05-13 19:39       ` Jeff Garzik [this message]
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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