From: Jakub Kicinski <kuba@kernel.org>
To: Haiyang Zhang <haiyangz@microsoft.com>
Cc: "sashal@kernel.org" <sashal@kernel.org>,
"linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
KY Srinivasan <kys@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
"olaf@aepfle.de" <olaf@aepfle.de>, vkuznets <vkuznets@redhat.com>,
"davem@davemloft.net" <davem@davemloft.net>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH V3,net-next, 1/2] hv_netvsc: Add XDP support
Date: Thu, 23 Jan 2020 09:30:13 -0800 [thread overview]
Message-ID: <20200123093013.53d78485@cakuba> (raw)
In-Reply-To: <MN2PR21MB13757F7D19C11EC175FD9F98CA0F0@MN2PR21MB1375.namprd21.prod.outlook.com>
On Thu, 23 Jan 2020 17:14:06 +0000, Haiyang Zhang wrote:
> > > Changes:
> > > v3: Minor code and comment updates.
> > > v2: Added XDP_TX support. Addressed review comments.
> >
> > How does the locking of the TX path work? You seem to be just calling the
> > normal xmit method, but you don't hold the xmit queue lock, so the stack can
> > start xmit concurrently, no?
>
> The netvsc and vmbus can handle concurrent transmits, except the msd
> (Multi-Send Data) field which can only be used by one queue.
>
> I already added a new flag to netvsc_send(), so packets from XDP_TX won't use
> the msd.
I see, there's a few non-atomic counters there, but maybe that's not a
big deal.
What frees the skb if the ring is full, and netvsc_send_pkt() returns
-EAGAIN? Nothing checks the return value from netvsc_xdp_xmit().
next prev parent reply other threads:[~2020-01-23 17:30 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-22 17:23 [PATCH V3,net-next, 0/2] hv_netvsc: Add XDP support Haiyang Zhang
2020-01-22 17:23 ` [PATCH V3,net-next, 1/2] " Haiyang Zhang
2020-01-22 19:51 ` Jesper Dangaard Brouer
2020-01-22 20:29 ` Haiyang Zhang
2020-01-23 16:59 ` Jakub Kicinski
2020-01-23 17:14 ` Haiyang Zhang
2020-01-23 17:30 ` Jakub Kicinski [this message]
2020-01-23 17:44 ` Haiyang Zhang
2020-01-22 17:23 ` [PATCH V3,net-next, 2/2] hv_netvsc: Update document for " Haiyang Zhang
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