From: "Iremonger, Bernard" <bernard.iremonger@intel.com>
To: "Richardson, Bruce" <bruce.richardson@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"Doherty, Declan" <declan.doherty@intel.com>,
"Ananyev, Konstantin" <konstantin.ananyev@intel.com>
Subject: Re: [dpdk-dev] [PATCH v3 3/4] bonding: take queue spinlock in rx/tx burst functions
Date: Mon, 13 Jun 2016 12:28:08 +0000 [thread overview]
Message-ID: <8CEF83825BEC744B83065625E567D7C21A038B2E@IRSMSX108.ger.corp.intel.com> (raw)
In-Reply-To: <20160613091800.GA17996@bricha3-MOBL3>
Hi Bruce,
<snip>
> Subject: Re: [dpdk-dev] [PATCH v3 3/4] bonding: take queue spinlock in rx/tx
> burst functions
>
> On Sun, Jun 12, 2016 at 06:11:28PM +0100, Bernard Iremonger wrote:
> > Use rte_spinlock_trylock() in the rx/tx burst functions to take the
> > queue spinlock.
> >
> > Signed-off-by: Bernard Iremonger <bernard.iremonger@intel.com>
> > Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> > ---
>
> Why does this particular PMD need spinlocks when doing RX and TX, while
> other device types do not? How is adding/removing devices from a bonded
> device different to other control operations that can be done on physical
> PMDs? Is this not similar to say bringing down or hotplugging out a physical
> port just before an RX or TX operation takes place?
> For all other PMDs we rely on the app to synchronise control and data plane
> operation - why not here?
>
> /Bruce
This issue arose during VM live migration testing.
For VM live migration it is necessary (while traffic is running) to be able to remove a bonded slave device, stop it, close it and detach it.
It a slave device is removed from a bonded device while traffic is running a segmentation fault may occur in the rx/tx burst function. The spinlock has been added to prevent this occurring.
The bonding device already uses a spinlock to synchronise between the add and remove functionality and the slave_link_status_change_monitor code.
Previously testpmd did not allow, stop, close or detach of PMD while traffic was running. Testpmd has been modified with the following patchset
http://dpdk.org/dev/patchwork/patch/13472/
It now allows stop, close and detach of a PMD provided in it is not forwarding and is not a slave of bonded PMD.
Regards,
Bernard.
next prev parent reply other threads:[~2016-06-13 12:28 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-05 15:14 [dpdk-dev] [PATCH 0/5] bonding: locks Bernard Iremonger
2016-05-05 15:14 ` [dpdk-dev] [PATCH 1/5] bonding: replace spinlock with read/write lock Bernard Iremonger
2016-05-05 17:12 ` Stephen Hemminger
2016-05-06 10:32 ` Declan Doherty
2016-05-06 15:55 ` Stephen Hemminger
2016-05-13 17:10 ` Ananyev, Konstantin
2016-05-13 17:18 ` Ananyev, Konstantin
2016-05-26 16:24 ` Iremonger, Bernard
2016-05-05 15:14 ` [dpdk-dev] [PATCH 2/5] bonding: add read/write lock to rx/tx burst functions Bernard Iremonger
2016-05-05 15:14 ` [dpdk-dev] [PATCH 3/5] bonding: remove memcopy of slaves from rx/tx burst function Bernard Iremonger
2016-05-05 15:14 ` [dpdk-dev] [PATCH 4/5] bonding: add read/write lock to stop function Bernard Iremonger
2016-05-05 15:15 ` [dpdk-dev] [PATCH 5/5] bonding: add read/write lock to the link_update function Bernard Iremonger
2016-05-26 16:38 ` [dpdk-dev] [PATCH v2 0/6] bonding: locks Bernard Iremonger
2016-05-26 16:38 ` [dpdk-dev] [PATCH v2 1/6] bonding: add spinlock to rx and tx queues Bernard Iremonger
2016-06-10 18:12 ` Ananyev, Konstantin
2016-06-12 17:11 ` [dpdk-dev] [PATCH v3 0/4] bonding: locks Bernard Iremonger
2016-06-12 17:11 ` [dpdk-dev] [PATCH v3 1/4] bonding: add spinlock to rx and tx queues Bernard Iremonger
2016-06-12 17:11 ` [dpdk-dev] [PATCH v3 2/4] bonding: grab queue spinlocks in slave add and remove Bernard Iremonger
2016-06-12 17:11 ` [dpdk-dev] [PATCH v3 3/4] bonding: take queue spinlock in rx/tx burst functions Bernard Iremonger
2016-06-13 9:18 ` Bruce Richardson
2016-06-13 12:28 ` Iremonger, Bernard [this message]
2016-06-16 14:32 ` Bruce Richardson
2016-06-16 15:00 ` Thomas Monjalon
2016-06-16 16:41 ` Iremonger, Bernard
2016-06-16 18:38 ` Thomas Monjalon
2017-02-15 18:01 ` Ferruh Yigit
2017-02-16 9:13 ` Bruce Richardson
2017-02-16 11:39 ` Iremonger, Bernard
2017-02-20 11:15 ` Ferruh Yigit
2016-09-09 11:29 ` Ferruh Yigit
2016-06-12 17:11 ` [dpdk-dev] [PATCH v3 4/4] bonding: remove memcpy from " Bernard Iremonger
2016-09-11 12:39 ` Yuanhan Liu
2016-05-26 16:38 ` [dpdk-dev] [PATCH v2 2/6] bonding: grab queue spinlocks in slave add and remove Bernard Iremonger
2016-06-10 18:14 ` Ananyev, Konstantin
2016-05-26 16:38 ` [dpdk-dev] [PATCH v2 3/6] bonding: take queue spinlock in rx/tx burst functions Bernard Iremonger
2016-06-10 18:14 ` Ananyev, Konstantin
2016-05-26 16:38 ` [dpdk-dev] [PATCH v2 4/6] bonding: add spinlock to stop function Bernard Iremonger
2016-05-26 16:38 ` [dpdk-dev] [PATCH v2 5/6] bonding: add spinlock to link update function Bernard Iremonger
2016-05-26 16:38 ` [dpdk-dev] [PATCH v2 6/6] bonding: remove memcpy from burst functions Bernard Iremonger
2016-06-10 18:15 ` Ananyev, Konstantin
2016-06-10 14:45 ` [dpdk-dev] [PATCH v2 0/6] bonding: locks Bruce Richardson
2016-06-10 18:24 ` Iremonger, Bernard
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