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Subject: Re: [Xen-devel] xen/evtchn and forced threaded irq
To:     Julien Grall <julien.grall@arm.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc:     Juergen Gross <jgross@suse.com>,
        Stefano Stabellini <sstabellini@kernel.org>,
        Andrew Cooper <Andrew.Cooper3@citrix.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Jan Beulich <JBeulich@suse.com>,
        xen-devel <xen-devel@lists.xenproject.org>,
        Dave P Martin <dave.martin@arm.com>
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From:   Oleksandr Andrushchenko <andr2000@gmail.com>
Message-ID: <13a9616c-2d9a-f90b-3358-f2dcadbbb64d@gmail.com>
Date:   Mon, 25 Feb 2019 15:24:24 +0200
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On 2/22/19 3:33 PM, Julien Grall wrote:
> Hi,
>
> On 22/02/2019 12:38, Oleksandr Andrushchenko wrote:
>> On 2/20/19 10:46 PM, Julien Grall wrote:
>>> Discussing with my team, a solution that came up would be to 
>>> introduce one atomic field per event to record the number of event 
>>> received. I will explore that solution tomorrow.
>> How will this help if events have some payload?
>
> What payload? The event channel does not carry any payload. It only 
> notify you that something happen. Then this is up to the user to 
> decide what to you with it.
Sorry, I was probably not precise enough. I mean that an event might have
associated payload in the ring buffer, for example [1]. So, counting events
may help somehow, but the ring's data may still be lost
>
> Cheers,
>
[1] 
https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=xen/include/public/io/displif.h;h=cc5de9cb1f35dedc99c866d73d086b19e496852a;hb=HEAD#l756