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From: Tom Rini <trini@konsulko.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [U-Boot, v2] tools: gen_eth_addr: add getpid() to time(0) to avoid duplicated seed
Date: Mon, 28 Sep 2015 17:08:36 -0400	[thread overview]
Message-ID: <20150928210836.GC22966@bill-the-cat> (raw)
In-Reply-To: <1442398864-1312-1-git-send-email-josh.wu@atmel.com>

On Wed, Sep 16, 2015 at 06:21:04PM +0800, Josh Wu wrote:

> As 'time(0) | getpid()' will have a lot of duplicated value. It is not a
> expected behavior. We expect different value for the seed when when run
> it in many times.
> 
> So this patch will left shift the getpid() and add to time(0). That
> avoid duplicated value.
> 
> Test command is like:
>   % RUN=0; while [ $RUN -lt 10000 ]; do
>   tools/gen_eth_addr; RUN=$(($RUN+1)); done | sort | uniq | wc -l
>   10000
> 
> This patch is incorporated with suggestions made by Wolfgang Denk and Andreas
> Bie?mann. Thanks them a lot.
> 
> Signed-off-by: Josh Wu <josh.wu@atmel.com>
> Acked-by: Andreas Bie?mann <andreas.devel@googlemail.com>
> Acked-by: Wolfgang Denk <wd@denx.de>
> Tested-by: Wolfgang Denk <wd@denx.de>

Applied to u-boot/master, thanks!

-- 
Tom
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      parent reply	other threads:[~2015-09-28 21:08 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-16 10:21 [U-Boot] [PATCH v2] tools: gen_eth_addr: add getpid() to time(0) to avoid duplicated seed Josh Wu
2015-09-16 10:29 ` Andreas Bießmann
2015-09-16 12:56 ` Wolfgang Denk
2015-09-28 21:08 ` Tom Rini [this message]

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