diff options
Diffstat (limited to 'target/linux/generic/patches-3.3/120-ppp_txqueue_restart.patch')
| -rw-r--r-- | target/linux/generic/patches-3.3/120-ppp_txqueue_restart.patch | 75 |
1 files changed, 0 insertions, 75 deletions
diff --git a/target/linux/generic/patches-3.3/120-ppp_txqueue_restart.patch b/target/linux/generic/patches-3.3/120-ppp_txqueue_restart.patch deleted file mode 100644 index e157133e9d..0000000000 --- a/target/linux/generic/patches-3.3/120-ppp_txqueue_restart.patch +++ /dev/null @@ -1,75 +0,0 @@ -commit 9a5d2bd99e0dfe9a31b3c160073ac445ba3d773f -Author: David Woodhouse <dwmw2@infradead.org> -Date: Sun Apr 8 10:01:44 2012 +0000 - - ppp: Fix race condition with queue start/stop - - Commit e675f0cc9a872fd152edc0c77acfed19bf28b81e ("ppp: Don't stop and - restart queue on every TX packet") introduced a race condition which - could leave the net queue stopped even when the channel is no longer - busy. By calling netif_stop_queue() from ppp_start_xmit(), based on the - return value from ppp_xmit_process() but *after* all the locks have been - dropped, we could potentially do so *after* the channel has actually - finished transmitting and attempted to re-wake the queue. - - Fix this by moving the netif_stop_queue() into ppp_xmit_process() under - the xmit lock. I hadn't done this previously, because it gets called - from other places than ppp_start_xmit(). But I now think it's the better - option. The net queue *should* be stopped if the channel becomes - congested due to writes from pppd, anyway. - - Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> - Signed-off-by: David S. Miller <davem@davemloft.net> - -commit e675f0cc9a872fd152edc0c77acfed19bf28b81e -Author: David Woodhouse <dwmw2@infradead.org> -Date: Mon Mar 26 00:03:42 2012 +0000 - - ppp: Don't stop and restart queue on every TX packet - - For every transmitted packet, ppp_start_xmit() will stop the netdev - queue and then, if appropriate, restart it. This causes the TX softirq - to run, entirely gratuitously. - - This is "only" a waste of CPU time in the normal case, but it's actively - harmful when the PPP device is a TEQL slave — the wakeup will cause the - offending device to receive the next TX packet from the TEQL queue, when - it *should* have gone to the next slave in the list. We end up seeing - large bursts of packets on just *one* slave device, rather than using - the full available bandwidth over all slaves. - - This patch fixes the problem by *not* unconditionally stopping the queue - in ppp_start_xmit(). It adds a return value from ppp_xmit_process() - which indicates whether the queue should be stopped or not. - - It *doesn't* remove the call to netif_wake_queue() from - ppp_xmit_process(), because other code paths (especially from - ppp_output_wakeup()) need it there and it's messy to push it out to the - other callers to do it based on the return value. So we leave it in - place — it's a no-op in the case where the queue wasn't stopped, so it's - harmless in the TX path. - - Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> - Signed-off-by: David S. Miller <davem@davemloft.net> - - - ---- a/drivers/net/ppp/ppp_generic.c -+++ b/drivers/net/ppp/ppp_generic.c -@@ -968,7 +968,6 @@ ppp_start_xmit(struct sk_buff *skb, stru - proto = npindex_to_proto[npi]; - put_unaligned_be16(proto, pp); - -- netif_stop_queue(dev); - skb_queue_tail(&ppp->file.xq, skb); - ppp_xmit_process(ppp); - return NETDEV_TX_OK; -@@ -1063,6 +1062,8 @@ ppp_xmit_process(struct ppp *ppp) - code that we can accept some more. */ - if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) - netif_wake_queue(ppp->dev); -+ else -+ netif_stop_queue(ppp->dev); - } - ppp_xmit_unlock(ppp); - } |