From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Rini Date: Mon, 28 Sep 2015 17:08:36 -0400 Subject: [U-Boot] [U-Boot, v2] tools: gen_eth_addr: add getpid() to time(0) to avoid duplicated seed In-Reply-To: <1442398864-1312-1-git-send-email-josh.wu@atmel.com> References: <1442398864-1312-1-git-send-email-josh.wu@atmel.com> Message-ID: <20150928210836.GC22966@bill-the-cat> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de 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 > Acked-by: Andreas Bie?mann > Acked-by: Wolfgang Denk > Tested-by: Wolfgang Denk Applied to u-boot/master, thanks! -- Tom -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: