2009-03-31 23:20:52

by Chris Wright

[permalink] [raw]
Subject: [patch 05/45] GRO: Disable GRO on legacy netif_rx path

-stable review patch. If anyone has any objections, please let us know.
---------------------

From: Herbert Xu <[email protected]>

[ Upstream commit 8f1ead2d1a626ed0c85b3d2c2046a49081d5933f ]

When I fixed the GRO crash in the legacy receive path I used
napi_complete to replace __napi_complete. Unfortunately they're
not the same when NETPOLL is enabled, which may result in us
not calling __napi_complete at all.

What's more, we really do need to keep the __napi_complete call
within the IRQ-off section since in theory an IRQ can occur in
between and fill up the backlog to the maximum, causing us to
lock up.

Since we can't seem to find a fix that works properly right now,
this patch reverts all the GRO support from the netif_rx path.

Signed-off-by: Herbert Xu <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
net/core/dev.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2588,18 +2588,15 @@ static int process_backlog(struct napi_s
local_irq_disable();
skb = __skb_dequeue(&queue->input_pkt_queue);
if (!skb) {
+ __napi_complete(napi);
local_irq_enable();
- napi_complete(napi);
- goto out;
+ break;
}
local_irq_enable();

- napi_gro_receive(napi, skb);
+ netif_receive_skb(skb);
} while (++work < quota && jiffies == start_time);

- napi_gro_flush(napi);
-
-out:
return work;
}