From: Thomas Monjalon <thomas@monjalon.net>
To: Phil Yang <phil.yang@arm.com>
Cc: erik.g.carrillo@intel.com, dev@dpdk.org, jerinj@marvell.com,
Honnappa.Nagarahalli@arm.com, drc@linux.vnet.ibm.com,
Ruifeng.Wang@arm.com, Dharmik.Thakkar@arm.com, nd@arm.com,
david.marchand@redhat.com, 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 12:04:10 +0200 [thread overview]
Message-ID: <3726677.YG9GXOvrMZ@thomas> (raw)
In-Reply-To: <1593667604-12029-4-git-send-email-phil.yang@arm.com>
02/07/2020 07:26, Phil Yang:
> The implementation-specific opaque data is shared between arm and cancel
> operations. The state flag acts as a guard variable to make sure the
> update of opaque data is synchronized. This patch uses c11 atomics with
> explicit one way memory barrier instead of full barriers rte_smp_w/rmb()
> to synchronize the opaque data between timer arm and cancel threads.
I think we should write C11 (uppercase).
Please, in your explanations, try to be more specific.
Naming fields may help to make things clear.
[...]
> --- 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.
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?
In any case, we need an explanation and an ABI check exception.
next prev parent reply other threads:[~2020-07-06 10:04 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 [this message]
2020-07-06 15:32 ` Phil Yang
2020-07-06 15:40 ` Thomas Monjalon
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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