From: Matt Mackall <mpm@selenic.com>
To: Jamie Lokier <jamie@shareable.org>
Cc: Andrew Morton <akpm@osdl.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 21/22] /dev/random: kill batching of entropy mixing
Date: Sat, 27 Mar 2004 09:17:29 -0600 [thread overview]
Message-ID: <20040327151728.GA6248@waste.org> (raw)
In-Reply-To: <20040327135245.GD21884@mail.shareable.org>
On Sat, Mar 27, 2004 at 01:52:45PM +0000, Jamie Lokier wrote:
> Matt Mackall wrote:
> > Rather than batching up entropy samples, resulting in longer lock hold
> > times when we actually process the samples, mix in samples
> > immediately. The trickle code should eliminate almost all the
> > additional interrupt-time overhead this would otherwise incur, with or
> > without locking.
>
> What do you mean by "the trickle code"? I didn't see anything in your
> patch set which makes the interrupt-time overhead faster.
This code which is in the existing driver to prevent pathological lock
contention on large SMP:
/* if over the trickle threshold, use only 1 in 4096 samples
*/
if ( input_pool.entropy_count > trickle_thresh &&
(__get_cpu_var(trickle_count)++ & 0xfff))
return;
--
Matt Mackall : http://www.selenic.com : Linux development and consulting
next prev parent reply other threads:[~2004-03-27 15:17 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-25 23:57 [PATCH 0/22] /dev/random: Assorted fixes and cleanups Matt Mackall
2004-03-25 23:57 ` [PATCH 1/22] /dev/random: Simplify entropy debugging Matt Mackall
2004-03-25 23:57 ` [PATCH 2/22] /dev/random: Cleanup sleep logic Matt Mackall
2004-03-25 23:57 ` [PATCH 3/22] /dev/random: remove broken resizing sysctl Matt Mackall
2004-03-25 23:57 ` [PATCH 4/22] /dev/random: remove outdated RNDGETPOOL ioctl Matt Mackall
2004-03-25 23:57 ` [PATCH 5/22] /dev/random: pool struct cleanup and rename Matt Mackall
2004-03-25 23:57 ` [PATCH 6/22] /dev/random: simplify pool initialization Matt Mackall
2004-03-25 23:57 ` [PATCH 7/22] /dev/random: simplify reseed logic Matt Mackall
2004-03-25 23:57 ` [PATCH 8/22] /dev/random: BUG on premature random users Matt Mackall
2004-03-25 23:57 ` [PATCH 9/22] /dev/random: more robust catastrophic reseed logic Matt Mackall
2004-03-25 23:57 ` [PATCH 10/22] /dev/random: entropy reserve logic for starvation preve Matt Mackall
2004-03-25 23:57 ` [PATCH 11/22] /dev/random: flag pools that need entropy reserve Matt Mackall
2004-03-25 23:57 ` [PATCH 12/22] /dev/random: add pool for /dev/urandom to prevent starv Matt Mackall
2004-03-25 23:57 ` [PATCH 13/22] /dev/random: kill extract_timer_state Matt Mackall
2004-03-25 23:57 ` [PATCH 14/22] /dev/random: kill unused md5 copy Matt Mackall
2004-03-25 23:57 ` [PATCH 15/22] /dev/random: kill unrolled SHA code Matt Mackall
2004-03-25 23:57 ` [PATCH 16/22] /dev/random: kill 2.2 cruft Matt Mackall
2004-03-25 23:57 ` [PATCH 17/22] /dev/random: minor shrinkage Matt Mackall
2004-03-25 23:57 ` [PATCH 18/22] /dev/random: bitop cleanup Matt Mackall
2004-03-25 23:57 ` [PATCH 19/22] /dev/random: use sched_clock for timing data Matt Mackall
2004-03-25 23:57 ` [PATCH 20/22] /dev/random: cleanup rol bitop Matt Mackall
2004-03-25 23:57 ` [PATCH 21/22] /dev/random: kill batching of entropy mixing Matt Mackall
2004-03-25 23:57 ` [PATCH 22/22] /dev/random: update credits Matt Mackall
2004-03-27 13:52 ` [PATCH 21/22] /dev/random: kill batching of entropy mixing Jamie Lokier
2004-03-27 15:17 ` Matt Mackall [this message]
2004-03-26 1:43 ` [PATCH 15/22] /dev/random: kill unrolled SHA code Jeff Garzik
2004-03-26 3:59 ` Matt Mackall
2004-03-27 13:49 ` Jamie Lokier
2004-03-26 0:15 ` [PATCH 4/22] /dev/random: remove outdated RNDGETPOOL ioctl Andrew Morton
2004-03-26 0:15 ` [PATCH 3/22] /dev/random: remove broken resizing sysctl Andrew Morton
2004-03-26 3:53 ` Matt Mackall
2004-03-26 0:14 ` [PATCH 2/22] /dev/random: Cleanup sleep logic Andrew Morton
2004-03-26 3:49 ` Matt Mackall
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