From: Wei Liu <wei.liu2@citrix.com>
To: Zoltan Kiss <zoltan.kiss@citrix.com>
Cc: jonathan.davies@citrix.com, wei.liu2@citrix.com,
ian.campbell@citrix.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org
Subject: Re: [PATCH net-next] xen-netback: Schedule NAPI from dealloc thread instead of callback
Date: Thu, 13 Mar 2014 10:17:20 +0000 [thread overview]
Message-ID: <20140313101720.GA16807@zion.uk.xensource.com> (raw)
In-Reply-To: <1394658281-2488-1-git-send-email-zoltan.kiss@citrix.com>
On Wed, Mar 12, 2014 at 09:04:41PM +0000, Zoltan Kiss wrote:
> If there are unconsumed requests in the ring, but there isn't enough free
> pending slots, the NAPI instance deschedule itself. As the frontend won't send
> any more interrupts in this case, it is the task of whoever release the pending
> slots to schedule the NAPI instance in this case. Originally it was done in the
> callback, but it's better at the end of the dealloc thread, otherwise there is
> a risk that the NAPI instance just deschedule itself as the dealloc thread
> couldn't release any used slot yet. However, as there are a lot of pending
> packets, NAPI will be scheduled again, and it is very unlikely that the dealloc
> thread can't release enough slots in the meantime.
>
So this patch restores the property that "only two parties access the
ring", right?
Wei.
next prev parent reply other threads:[~2014-03-13 10:17 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-12 21:04 [PATCH net-next] xen-netback: Schedule NAPI from dealloc thread instead of callback Zoltan Kiss
2014-03-13 10:17 ` Wei Liu [this message]
2014-03-13 10:42 ` Ian Campbell
2014-03-13 15:44 ` Zoltan Kiss
2014-03-13 19:48 ` David Miller
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