* [PATCH net] net: add cpu_relax to busy poll loop
@ 2013-08-25 7:23 Eliezer Tamir
2013-08-28 21:46 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Eliezer Tamir @ 2013-08-25 7:23 UTC (permalink / raw)
To: David Miller; +Cc: linux-kernel, netdev, Eliezer Tamir
Add a cpu_relaxt to sk_busy_loop.
Julie Cummings reported performance issues when hyperthreading is on.
Arjan van de Ven observed that we should have a cpu_relax() in the
busy poll loop.
Reported-by: Julie Cummings <julie.a.cummings@intel.com>
Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
---
include/net/busy_poll.h | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index 8a358a2..829627d 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -123,6 +123,7 @@ static inline bool sk_busy_loop(struct sock *sk, int nonblock)
/* local bh are disabled so it is ok to use _BH */
NET_ADD_STATS_BH(sock_net(sk),
LINUX_MIB_BUSYPOLLRXPACKETS, rc);
+ cpu_relax();
} while (!nonblock && skb_queue_empty(&sk->sk_receive_queue) &&
!need_resched() && !busy_loop_timeout(end_time));
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH net] net: add cpu_relax to busy poll loop
2013-08-25 7:23 [PATCH net] net: add cpu_relax to busy poll loop Eliezer Tamir
@ 2013-08-28 21:46 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2013-08-28 21:46 UTC (permalink / raw)
To: eliezer.tamir; +Cc: linux-kernel, netdev, eliezer
From: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Date: Sun, 25 Aug 2013 10:23:46 +0300
> Add a cpu_relaxt to sk_busy_loop.
>
> Julie Cummings reported performance issues when hyperthreading is on.
> Arjan van de Ven observed that we should have a cpu_relax() in the
> busy poll loop.
>
> Reported-by: Julie Cummings <julie.a.cummings@intel.com>
> Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Applied, thank you.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2013-08-25 7:23 [PATCH net] net: add cpu_relax to busy poll loop Eliezer Tamir
2013-08-28 21:46 ` David Miller
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