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From: Thomas Monjalon <thomas@monjalon.net>
To: Phil Yang <Phil.Yang@arm.com>
Cc: "erik.g.carrillo@intel.com" <erik.g.carrillo@intel.com>,
	"dev@dpdk.org" <dev@dpdk.org>,
	"jerinj@marvell.com" <jerinj@marvell.com>,
	Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>,
	"drc@linux.vnet.ibm.com" <drc@linux.vnet.ibm.com>,
	Ruifeng Wang <Ruifeng.Wang@arm.com>,
	Dharmik Thakkar <Dharmik.Thakkar@arm.com>, nd <nd@arm.com>,
	"david.marchand@redhat.com" <david.marchand@redhat.com>,
	"mdr@ashroe.eu" <mdr@ashroe.eu>,
	Neil Horman <nhorman@tuxdriver.com>,
	Dodji Seketeli <dodji@redhat.com>
Subject: Re: [dpdk-dev] [PATCH v2 4/4] eventdev: relax smp barriers with c11 atomics
Date: Mon, 06 Jul 2020 17:40:27 +0200	[thread overview]
Message-ID: <1943904.n5iF1h13R9@thomas> (raw)
In-Reply-To: <VE1PR08MB464059BB58F29658224D4A58E9690@VE1PR08MB4640.eurprd08.prod.outlook.com>

06/07/2020 17:32, Phil Yang:
> From: Thomas Monjalon <thomas@monjalon.net>
> > 02/07/2020 07:26, Phil Yang:
> > > --- a/lib/librte_eventdev/rte_event_timer_adapter.h
> > > +++ b/lib/librte_eventdev/rte_event_timer_adapter.h
> > > @@ -467,7 +467,7 @@ struct rte_event_timer {
> > >  	 *  - op: RTE_EVENT_OP_NEW
> > >  	 *  - event_type: RTE_EVENT_TYPE_TIMER
> > >  	 */
> > > -	volatile enum rte_event_timer_state state;
> > > +	enum rte_event_timer_state state;
> > >  	/**< State of the event timer. */
> > 
> > Why do you remove the volatile keyword?
> > It is not explained in the commit log.
> By using the C11 atomic operations, it will generate the same instructions for non-volatile and volatile version.
> Please check the sample code here: https://gcc.godbolt.org/z/8x5rWs
> 
> > This change is triggering a warning in the ABI check:
> > http://mails.dpdk.org/archives/test-report/2020-July/140440.html
> > Moving from volatile to non-volatile is probably not an issue.
> > I expect the code generated for the volatile case to work the same
> > in non-volatile case. Do you confirm?
> They generate the same instructions, so either way will work.
> Do I need to revert it to the volatile version?

Either you revert, or you add explanation in the commit log
+ exception in libabigail.abignore



  reply	other threads:[~2020-07-06 15:40 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-12 11:19 [dpdk-dev] [PATCH 1/3] eventdev: fix race condition on timer list counter Phil Yang
2020-06-12 11:19 ` [dpdk-dev] [PATCH 2/3] eventdev: use c11 atomics for lcore timer armed flag Phil Yang
2020-06-23 21:01   ` Carrillo, Erik G
2020-06-28 16:12     ` Phil Yang
2020-06-23 21:20   ` Stephen Hemminger
2020-06-23 21:31     ` Carrillo, Erik G
2020-06-28 16:32       ` Phil Yang
2020-06-12 11:19 ` [dpdk-dev] [PATCH 3/3] eventdev: relax smp barriers with c11 atomics Phil Yang
2020-06-22 10:12   ` Phil Yang
2020-06-23 19:38     ` Carrillo, Erik G
2020-06-28 17:33       ` Phil Yang
2020-06-29 18:07         ` Carrillo, Erik G
2020-06-18 15:17 ` [dpdk-dev] [PATCH 1/3] eventdev: fix race condition on timer list counter Carrillo, Erik G
2020-06-18 18:25   ` Honnappa Nagarahalli
2020-06-22  9:48     ` Phil Yang
2020-07-01 11:22       ` Jerin Jacob
2020-07-02  3:28         ` Phil Yang
2020-07-02  3:26     ` Phil Yang
2020-07-02  3:56       ` Honnappa Nagarahalli
2020-07-02 21:15         ` Carrillo, Erik G
2020-07-02 21:30           ` Honnappa Nagarahalli
2020-06-22  9:09   ` Phil Yang
2020-07-02  5:26 ` [dpdk-dev] [PATCH v2 1/4] " Phil Yang
2020-07-02  5:26   ` [dpdk-dev] [PATCH v2 2/4] eventdev: use c11 atomics for lcore timer armed flag Phil Yang
2020-07-02 20:21     ` Carrillo, Erik G
2020-07-02  5:26   ` [dpdk-dev] [PATCH v2 3/4] eventdev: remove redundant code Phil Yang
2020-07-03  3:35     ` Dharmik Thakkar
2020-07-02  5:26   ` [dpdk-dev] [PATCH v2 4/4] eventdev: relax smp barriers with c11 atomics Phil Yang
2020-07-02 20:30     ` Carrillo, Erik G
2020-07-03 10:50       ` Jerin Jacob
2020-07-06 10:04     ` Thomas Monjalon
2020-07-06 15:32       ` Phil Yang
2020-07-06 15:40         ` Thomas Monjalon [this message]
2020-07-07 11:13   ` [dpdk-dev] [PATCH v3 1/4] eventdev: fix race condition on timer list counter Phil Yang
2020-07-07 11:13     ` [dpdk-dev] [PATCH v3 2/4] eventdev: use C11 atomics for lcore timer armed flag Phil Yang
2020-07-07 11:13     ` [dpdk-dev] [PATCH v3 3/4] eventdev: remove redundant code Phil Yang
2020-07-07 11:13     ` [dpdk-dev] [PATCH v3 4/4] eventdev: relax smp barriers with C11 atomics Phil Yang
2020-07-07 14:29       ` Jerin Jacob
2020-07-07 15:56         ` Phil Yang
2020-07-07 15:54     ` [dpdk-dev] [PATCH v4 1/4] eventdev: fix race condition on timer list counter Phil Yang
2020-07-07 15:54       ` [dpdk-dev] [PATCH v4 2/4] eventdev: use C11 atomics for lcore timer armed flag Phil Yang
2020-07-07 15:54       ` [dpdk-dev] [PATCH v4 3/4] eventdev: remove redundant code Phil Yang
2020-07-07 15:54       ` [dpdk-dev] [PATCH v4 4/4] eventdev: relax smp barriers with C11 atomics Phil Yang
2020-07-08 13:30       ` [dpdk-dev] [PATCH v4 1/4] eventdev: fix race condition on timer list counter Jerin Jacob
2020-07-08 15:01         ` Thomas Monjalon

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