From: Matt Mackall <mpm@selenic.com>
To: Ian Molton <ian.molton@collabora.co.uk>
Cc: rusty@rustcorp.com.au, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] hw_random: core updates to allow more efficient drivers
Date: Wed, 25 Nov 2009 19:03:23 -0600 [thread overview]
Message-ID: <1259197403.2858.88.camel@calx> (raw)
In-Reply-To: <1259195127-20086-2-git-send-email-ian.molton@collabora.co.uk>
On Thu, 2009-11-26 at 00:25 +0000, Ian Molton wrote:
> This patch implements a new method by which hw_random hardware drivers
> can pass data to the core more efficiently, using a shared buffer.
>
> The old methods have been retained as a compatability layer until all the
> drivers have been updated.
>
> Signed-off-by: Ian Molton <ian.molton@collabora.co.uk>
> ---
> drivers/char/hw_random/core.c | 120 ++++++++++++++++++++++++++---------------
> include/linux/hw_random.h | 9 ++-
> 2 files changed, 82 insertions(+), 47 deletions(-)
>
> diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
> index 1573aeb..e179afd 100644
> --- a/drivers/char/hw_random/core.c
> +++ b/drivers/char/hw_random/core.c
> @@ -47,12 +47,14 @@
> #define RNG_MODULE_NAME "hw_random"
> #define PFX RNG_MODULE_NAME ": "
> #define RNG_MISCDEV_MINOR 183 /* official */
> +#define RNG_BUFFSIZE 64
>
>
> static struct hwrng *current_rng;
> static LIST_HEAD(rng_list);
> static DEFINE_MUTEX(rng_mutex);
> -
> +static u8 *rng_buffer;
How about just:
static u8 rng_buffer[RNG_BUFFSIZE] __cacheline_aligned;
And lose all the kmalloc and kfree code? The memory use will be smaller,
even when the buffer isn't needed.
> + if (!data_avail) {
> + bytes_read = rng_get_data(current_rng, rng_buffer,
> + RNG_BUFFSIZE, !(filp->f_flags & O_NONBLOCK));
No need to pass rng_buffer to the helper as there's only one with global
scope.
--
http://selenic.com : development and support for Mercurial and Linux
next prev parent reply other threads:[~2009-11-26 1:03 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <4B080621.5000109@collabora.co.uk>
[not found] ` <4B0C18B0.2000206@collabora.co.uk>
[not found] ` <1259084901.17871.624.camel@calx>
[not found] ` <200911251135.41871.rusty@rustcorp.com.au>
[not found] ` <4B0D03FC.40406@collabora.co.uk>
2009-11-25 19:27 ` hw_random fixes Matt Mackall
2009-11-25 20:43 ` Ian Molton
2009-11-26 0:25 ` Ian Molton
2009-11-26 0:25 ` [PATCH 1/2] hw_random: core updates to allow more efficient drivers Ian Molton
2009-11-26 0:25 ` [PATCH 2/2] virtio: Convert virtio-rng to the new API Ian Molton
2009-11-28 10:00 ` Rusty Russell
2009-11-30 9:55 ` Ian Molton
2009-11-26 1:03 ` Matt Mackall [this message]
2009-11-26 10:49 ` Ian Molton
2009-11-26 10:49 ` [PATCH 1/2] hw_random: core updates to allow more efficient drivers Ian Molton
2009-11-26 11:38 ` Matt Mackall
2009-11-26 11:48 ` Re: Ian Molton
2009-11-27 22:54 ` Re: Matt Mackall
2009-11-28 0:51 ` rng updates Ian Molton
2009-11-28 10:05 ` [PATCH 1/2] hw_random: core updates to allow more efficient drivers Rusty Russell
2009-11-30 10:28 ` Ian Molton
2009-11-30 18:44 ` Matt Mackall
2009-12-01 3:08 ` Rusty Russell
2009-12-01 9:23 ` Ian Molton
2009-12-01 9:18 ` Ian Molton
2009-11-26 3:12 ` Jeff Garzik
2009-11-26 0:44 ` Ian Molton
2009-11-26 0:44 ` [PATCH 1/2] hw_random: core updates to allow more efficient drivers Ian Molton
2009-11-26 0:44 ` [PATCH 2/2] virtio: Convert virtio-rng to the new API Ian Molton
2009-11-30 10:38 ` hw_random update Ian Molton
2009-11-30 10:38 ` [PATCH 1/2] hw_random: core updates to allow more efficient drivers Ian Molton
2009-11-30 10:38 ` [PATCH 2/2] virtio: Convert virtio-rng to the new API Ian Molton
2009-12-01 7:27 ` Herbert Xu
2009-12-01 9:29 ` Ian Molton
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