renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-19 02:34:01 +08:00
Code

net: don't keep lonely packets forever in the gro hash

Browse Source 
Eric noted that with UDP GRO and NAPI timeout, we could keep a single
UDP packet inside the GRO hash forever, if the related NAPI instance
calls napi_gro_complete() at an higher frequency than the NAPI timeout.
Willem noted that even TCP packets could be trapped there, till the
next retransmission.
This patch tries to address the issue, flushing the old packets -
those with a NAPI_GRO_CB age before the current jiffy - before scheduling
the NAPI timeout. The rationale is that such a timeout should be
well below a jiffy and we are not flushing packets eligible for sane GRO.

v1  -> v2:
 - clarified the commit message and comment

RFC -> v1:
 - added 'Fixes tags', cleaned-up the wording.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: 3b47d30396 ("net: gro: add a per device gro flush timer")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Paolo Abeni 2018-11-21 18:21:35 +01:00 committed by David S. Miller
parent 896585d48e
commit 605108acfe
1 changed files with 5 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
net/core/dev.c
View File

@ -5970,11 +5970,14 @@ bool napi_complete_done(struct napi_struct *n, int work_done)
if (work_done)
timeout = n->dev->gro_flush_timeout;
/* When the NAPI instance uses a timeout and keeps postponing
* it, we need to bound somehow the time packets are kept in
* the GRO layer
*/
napi_gro_flush(n, !!timeout);
if (timeout)
hrtimer_start(&n->timer, ns_to_ktime(timeout),
HRTIMER_MODE_REL_PINNED);
else
napi_gro_flush(n, false);
}
if (unlikely(!list_empty(&n->poll_list))) {
/* If n->poll_list is not empty, we need to mask irqs */