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From: "Theodore Ts'o" <tytso@mit.edu>
To: George Spelvin <linux@horizon.com>
Cc: hpa@linux.intel.com, price@mit.edu, linux-kernel@vger.kernel.org,
	mingo@kernel.org
Subject: Re: [RFC PATCH] drivers/char/random.c: Is reducing locking range like this safe?
Date: Sun, 8 Jun 2014 21:35:53 -0400	[thread overview]
Message-ID: <20140609013553.GA1167@thunk.org> (raw)
In-Reply-To: <20140609000524.19476.qmail@ns.horizon.com>

On Sun, Jun 08, 2014 at 08:05:24PM -0400, George Spelvin wrote:
> 
> The problem I started trying to solve is readers (entropy extractors)
> monopolizing the pool lock and stalling writers (entropy mixers), which
> are supposed to be fast and low overhead.

Which writer are you worried about, specifically?  A userspace write
to /dev/random from rgnd?

And have you measured this to be something significant, or is this a
theoretical concern.  If you've measured it, what's the conditions
where this is stalling an entropy mixer a significant amount of time?

      	      	       	  	  	  - Ted

  reply	other threads:[~2014-06-09  1:36 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-09  0:05 [RFC PATCH] drivers/char/random.c: Is reducing locking range like this safe? George Spelvin
2014-06-09  1:35 ` Theodore Ts'o [this message]
2014-06-09  2:10   ` George Spelvin
2014-06-09  2:18     ` George Spelvin
2014-06-09  4:03       ` George Spelvin
2014-06-09  9:23         ` George Spelvin
2014-06-09 13:34         ` Theodore Ts'o
2014-06-09 15:04           ` George Spelvin
2014-06-09 15:50             ` Theodore Ts'o
2014-06-09 16:11               ` George Spelvin
2014-06-10  0:20               ` drivers/char/random.c: more ruminations George Spelvin
2014-06-10  1:20                 ` Theodore Ts'o
2014-06-10  3:10                   ` George Spelvin
2014-06-10 15:25                     ` Theodore Ts'o
2014-06-10 20:40                       ` George Spelvin
2014-06-10 21:20                         ` Theodore Ts'o
2014-06-11  0:10                           ` George Spelvin
2014-06-11  2:08                             ` Theodore Ts'o
2014-06-11  3:58                               ` George Spelvin
2014-06-11 13:11                                 ` Theodore Ts'o
2014-06-12  0:42                                   ` George Spelvin
2014-06-12  1:03                                   ` H. Peter Anvin
2014-06-11  4:34                               ` George Spelvin
2014-06-11 13:09                                 ` Theodore Ts'o
2014-06-11  2:21                             ` Theodore Ts'o
2014-06-09 13:17   ` drivers/char/random.c: More futzing about George Spelvin
2014-06-11 16:38     ` Theodore Ts'o
2014-06-11 16:48       ` H. Peter Anvin
2014-06-11 19:25         ` Theodore Ts'o
2014-06-11 20:41           ` H. Peter Anvin
2014-06-12  0:44             ` H. Peter Anvin
2014-06-12  1:51               ` George Spelvin
2014-06-12  0:32       ` George Spelvin
2014-06-12  3:22         ` Theodore Ts'o
2014-06-12  4:13           ` random: Benchamrking fast_mix2 George Spelvin
2014-06-12 11:18             ` George Spelvin
2014-06-12 20:17               ` Theodore Ts'o
2014-06-12 20:46               ` Theodore Ts'o
2014-06-13  0:23                 ` George Spelvin
2014-06-13 15:52                   ` Theodore Ts'o
2014-06-14  2:10                     ` George Spelvin
2014-06-14  3:06                       ` Theodore Ts'o
2014-06-14  5:25                         ` George Spelvin
2014-06-14  6:24                           ` Theodore Ts'o
2014-06-14  8:03                             ` George Spelvin
2014-06-14 11:14                               ` George Spelvin
2014-06-14 15:13                                 ` George Spelvin
2014-06-14 16:33                                   ` Theodore Ts'o
2014-06-15  0:23                                     ` George Spelvin
2014-06-15  1:17                                       ` Theodore Ts'o
2014-06-15  6:58                                         ` George Spelvin
2014-06-15 13:01                                           ` Theodore Ts'o
2014-06-14  6:27                           ` Theodore Ts'o
2014-06-14  4:55                     ` [RFC] random: is the IRQF_TIMER test working as intended? George Spelvin
2014-06-14  6:43                       ` Theodore Ts'o
2014-06-14  7:23                         ` George Spelvin
2014-06-12  3:43       ` drivers/char/random.c: More futzing about George Spelvin

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