From: "Michael S. Tsirkin" <mst@redhat.com>
To: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: "Jason Wang" <jasowang@redhat.com>,
netdev@vger.kernel.org, "Eugenio Pérez" <eperezma@redhat.com>,
"Andrew Lunn" <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
"Eric Dumazet" <edumazet@google.com>,
"Jakub Kicinski" <kuba@kernel.org>,
"Paolo Abeni" <pabeni@redhat.com>,
"Alexei Starovoitov" <ast@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Jesper Dangaard Brouer" <hawk@kernel.org>,
"John Fastabend" <john.fastabend@gmail.com>,
"Stanislav Fomichev" <sdf@fomichev.me>,
virtualization@lists.linux.dev, linux-kernel@vger.kernel.org,
bpf@vger.kernel.org, "Bui Quang Minh" <minhquangbui99@gmail.com>
Subject: Re: [PATCH net 1/3] virtio-net: make refill work a per receive queue work
Date: Tue, 23 Dec 2025 20:47:50 -0500 [thread overview]
Message-ID: <20251223204555-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <1766540234.3618076-1-xuanzhuo@linux.alibaba.com>
On Wed, Dec 24, 2025 at 09:37:14AM +0800, Xuan Zhuo wrote:
>
> Hi Jason,
>
> I'm wondering why we even need this refill work. Why not simply let NAPI retry
> the refill on its next run if the refill fails? That would seem much simpler.
> This refill work complicates maintenance and often introduces a lot of
> concurrency issues and races.
>
> Thanks.
refill work can refill from GFP_KERNEL, napi only from ATOMIC.
And if GFP_ATOMIC failed, aggressively retrying might not be a great idea.
Not saying refill work is a great hack, but that is the reason for it.
--
MST
next prev parent reply other threads:[~2025-12-24 1:47 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-23 15:25 [PATCH net 0/3] virtio-net: fix the deadlock when disabling rx NAPI Bui Quang Minh
2025-12-23 15:25 ` [PATCH net 1/3] virtio-net: make refill work a per receive queue work Bui Quang Minh
2025-12-24 0:52 ` Jason Wang
2025-12-24 1:37 ` Xuan Zhuo
2025-12-24 1:47 ` Michael S. Tsirkin [this message]
2025-12-24 16:49 ` Bui Quang Minh
2025-12-25 15:55 ` Bui Quang Minh
2025-12-25 16:27 ` Michael S. Tsirkin
2025-12-25 7:33 ` Jason Wang
2025-12-25 16:27 ` Michael S. Tsirkin
2025-12-26 1:31 ` Jason Wang
2025-12-26 7:37 ` Michael S. Tsirkin
2025-12-29 2:57 ` Jason Wang
2025-12-30 16:28 ` Bui Quang Minh
2025-12-30 16:44 ` Michael S. Tsirkin
2025-12-31 7:30 ` Jason Wang
2025-12-24 16:43 ` Bui Quang Minh
2025-12-24 1:34 ` Michael S. Tsirkin
2025-12-24 10:19 ` Michael S. Tsirkin
2025-12-24 17:03 ` Bui Quang Minh
2025-12-23 15:25 ` [PATCH net 2/3] virtio-net: ensure rx NAPI is enabled before enabling refill work Bui Quang Minh
2025-12-24 1:45 ` Michael S. Tsirkin
2025-12-24 17:49 ` Bui Quang Minh
2025-12-24 10:20 ` Michael S. Tsirkin
2025-12-23 15:25 ` [PATCH net 3/3] virtio-net: schedule the pending refill work after being enabled Bui Quang Minh
2025-12-24 10:17 ` Michael S. Tsirkin
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