From: "Jan Beulich" <JBeulich@suse.com>
To: David Vrabel <david.vrabel@citrix.com>
Cc: xen-devel@lists.xenproject.org, Keir Fraser <keir@xen.org>,
Ian Campbell <ian.campbell@citrix.com>, Tim Deegan <tim@xen.org>
Subject: Re: [PATCHv3 4/6] evtchn: use a per-event channel lock for sending events
Date: Thu, 18 Jun 2015 12:20:12 +0100 [thread overview]
Message-ID: <5582C58C020000780008692C@mail.emea.novell.com> (raw)
In-Reply-To: <1434542583-28073-5-git-send-email-david.vrabel@citrix.com>
>>> On 17.06.15 at 14:03, <david.vrabel@citrix.com> wrote:
> When sending an event, use a new per-event channel lock to safely
> validate the event channel state.
>
> This new lock must be held when changing event channel state. Note
> that the event channel lock must also be held when changing state from
> ECS_FREE or it will race with a concurrent get_free_port() call.
>
> To avoid having to take the remote event channel locks when sending to
> an interdomain event channel, the local and remote channel locks are
> both held when binding or closing an interdomain event channel.
>
> This significantly increases the number of events that can be sent
> from multiple VCPUs. But struct evtchn increases in size, reducing
> the number that fit into a single page to 64 (instead of 128).
>
> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
But iiuc this functionally depends on the earlier patches, and
hence can't go in without the issues there addressed.
Jan
next prev parent reply other threads:[~2015-06-18 11:20 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-17 12:02 [PATCHv3 0/6] evtchn: Improve scalebility David Vrabel
2015-06-17 12:02 ` [PATCHv3 1/6] evtchn: clear xen_consumer when clearing state David Vrabel
2015-06-18 10:30 ` Jan Beulich
2015-06-17 12:02 ` [PATCHv3 2/6] evtchn: defer freeing struct evtchn's until evtchn_destroy_final() David Vrabel
2015-06-18 10:36 ` Jan Beulich
2015-06-18 10:40 ` David Vrabel
2015-06-18 11:01 ` Jan Beulich
2015-06-19 9:29 ` Jan Beulich
2015-06-19 9:52 ` David Vrabel
2015-06-19 10:55 ` Jan Beulich
2015-06-19 12:23 ` David Vrabel
2015-06-19 13:04 ` Jan Beulich
2015-06-19 16:58 ` David Vrabel
2015-06-17 12:03 ` [PATCHv3 3/6] evtchn: simplify port_is_valid() David Vrabel
2015-06-17 12:03 ` [PATCHv3 4/6] evtchn: use a per-event channel lock for sending events David Vrabel
2015-06-18 11:20 ` Jan Beulich [this message]
2015-06-18 11:39 ` David Vrabel
2015-06-17 12:03 ` [PATCHv3 5/6] evtchn: remove the locking when unmasking an event channel David Vrabel
2015-06-18 11:30 ` Jan Beulich
2015-06-18 11:36 ` David Vrabel
2015-06-18 12:08 ` Jan Beulich
2015-06-18 12:17 ` David Vrabel
2015-06-17 12:03 ` [PATCHv3 6/6] evtchn: pad struct evtchn to 64 bytes David Vrabel
2015-06-18 11:31 ` Jan Beulich
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