From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruce Richardson Subject: Re: [PATCH] eal: initialize alarms early Date: Thu, 28 Mar 2019 10:43:14 +0000 Message-ID: <20190328104313.GA1418@bricha3-MOBL.ger.corp.intel.com> References: <20190326184331.13850-1-dariusz.stojaczyk@intel.com> <2545420.xP4CxeWPSp@xps> <1752426.1oQredii45@xps> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Stojaczyk, Dariusz" , "dev@dpdk.org" , "Zhang, Qi Z" , "Burakov, Anatoly" , "stable@dpdk.org" To: Thomas Monjalon Return-path: Content-Disposition: inline In-Reply-To: <1752426.1oQredii45@xps> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Wed, Mar 27, 2019 at 11:42:40PM +0100, Thomas Monjalon wrote: > 27/03/2019 21:33, Stojaczyk, Dariusz: > > From: Thomas Monjalon [mailto:thomas@monjalon.net] > > > 26/03/2019 19:43, Darek Stojaczyk: > > > > We currently initialize rte_alarms after starting > > > > to listen for IPC hotplug requests, which gives > > > > us a data race window. Upon receiving such hotplug > > > > request we always try to set an alarm and this > > > > obviously doesn't work if the alarms weren't > > > > initialized yet. > > > > > > > > To fix it, we initialize alarms before starting > > > > to listen for IPC hotplug messages. Specifically, > > > > we move rte_eal_alarm_init() right after > > > > rte_eal_intr_init() as it makes some sense to > > > > keep those two close to each other. > > > > > > I wonder which regression it will bring :) > > > The experience shows that we cannot touch this function > > > without introducing a regression. Please check twice. > > > > Hah, ok - I'll check again the possible outcomes of this. > > > > > > > > > Fixes: 244d5130719c ("eal: enable hotplug on multi-process") > > > > Cc: Qi Zhang > > > > Cc: Anatoly Burakov > > > > Cc: stable@dpdk.org > > > > > > > > Signed-off-by: Darek Stojaczyk > > > > --- > > > > lib/librte_eal/linux/eal/eal.c | 12 ++++++------ > > > > 1 file changed, 6 insertions(+), 6 deletions(-) > > > > > > You probably need to update the FreeBSD version too. > > > > > > > Oh, that I cannot do. First of all, in bsd code I don't see > > rte_mp_dev_hotplug_init() called anywhere, as if bsd > > did not listen for IPC hotplug messages at all and hence did > > not have any data race in this area. Second, I would be > > afraid to touch any bsd code as I'm not running any bsd > > system. > > The problem is the consistency between OSes. > May you ask help here? Bruce is maintaining the FreeBSD side. > I don't think we support IPC or hotplug on BSD, so I don't think this patch is relevant on the BSD side. /Bruce