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From: Greg Price <price@MIT.EDU>
To: "Theodore Ts'o" <tytso@MIT.EDU>,
	linux-kernel@vger.kernel.org, Jiri Kosina <jkosina@suse.cz>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH 9/9] random: simplify accounting code
Date: Fri, 6 Dec 2013 13:25:04 -0500	[thread overview]
Message-ID: <20131206182503.GK8043@ringworld.MIT.EDU> (raw)
In-Reply-To: <20131206011347.GD9010@thunk.org>

On Thu, Dec 05, 2013 at 08:13:47PM -0500, Theodore Ts'o wrote:
> On Wed, Nov 13, 2013 at 03:08:41AM -0500, Greg Price wrote:
> > +	if (ibytes && cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
> > +		goto retry;
> 
> I wonder if we would be better dropping the test for ibytes here, so
> the above condition reads:
> 
> 	if (cmpxchg(&r->entropy_count, orig, entropy_count) != orig)
> 		goto retry;
> 
> It further simplifies the code, and it means that if we it turns out
> that ibytes is zero (meaning there was no entropy available) but some
> additional entropy comes in, we might acutally end up retrying and
> successfully grabbing that entropy for the caller.

Sure, that'd be reasonable.  I didn't do that mainly because I wanted
to preserve existing behavior wherever possible in these cleanups, to
make them easy to read and review.

Greg


  reply	other threads:[~2013-12-06 18:25 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-13  8:07 [PATCH v2 0/9] random: code cleanups Greg Price
2013-11-13  8:07 ` [PATCH 1/9] random: fix typos / spelling errors in comments Greg Price
2013-11-29 19:56   ` Theodore Ts'o
2013-11-13  8:07 ` [PATCH 2/9] random: fix comment on proc_do_uuid Greg Price
2013-11-29 19:59   ` Theodore Ts'o
2013-11-13  8:07 ` [PATCH 3/9] random: fix description of get_random_bytes Greg Price
2013-11-29 20:00   ` Theodore Ts'o
2013-11-13  8:07 ` [PATCH 4/9] random: simplify loop in random_read Greg Price
2013-11-29 20:09   ` Theodore Ts'o
2013-11-30  5:30     ` Greg Price
2013-11-13  8:08 ` [PATCH 5/9] random: fix comment on "account" Greg Price
2013-11-29 20:53   ` Theodore Ts'o
2013-11-13  8:08 ` [PATCH 6/9] random: simplify accounting logic Greg Price
2013-11-30  1:04   ` Theodore Ts'o
2013-11-13  8:08 ` [PATCH 7/9] random: forget lock in lockless accounting Greg Price
2013-11-30  1:10   ` Theodore Ts'o
2013-11-13  8:08 ` [PATCH 8/9] random: tighten bound on random_read_wakeup_thresh Greg Price
2013-12-06  0:31   ` Theodore Ts'o
2013-11-13  8:08 ` [PATCH 9/9] random: simplify accounting code Greg Price
2013-12-06  1:13   ` Theodore Ts'o
2013-12-06 18:25     ` Greg Price [this message]
2013-12-07 14:48       ` Theodore Ts'o

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