aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorFrancois Romieu <romieu@fr.zoreil.com>2012-06-09 10:53:16 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-01-21 11:45:24 -0800
commitced8dfbc6b44c7b14204a13ff95f22bdee52578f (patch)
tree18b8a3a8526bbe4064efa97ffae839d57e6bd99f
parent5c9611090f9d110a245cc54ddb9bb31b2cc2965f (diff)
downloadlinux-linaro-stable-ced8dfbc6b44c7b14204a13ff95f22bdee52578f.tar.gz
r8169: avoid NAPI scheduling delay.
commit 7dbb491878a2c51d372a8890fa45a8ff80358af1 upstream. While reworking the r8169 driver a few months ago to perform the smallest amount of work in the irq handler, I took care of avoiding any irq mask register operation in the slow work dedicated user context thread. The slow work thread scheduled an extra round of NAPI work which would ultimately set the irq mask register as required, thus keeping such irq mask operations in the NAPI handler. It would eventually race with the irq handler and delay NAPI execution for - assuming no further irq - a whole ksoftirqd period. Mildly a problem for rare link changes or corner case PCI events. The race was always lost after the last bh disabling lock had been removed from the work thread and people started wondering where those pesky "NOHZ: local_softirq_pending 08" messages came from. Actually the irq mask register _can_ be set up directly in the slow work thread. Signed-off-by: Francois Romieu <romieu@fr.zoreil.com> Reported-by: Dave Jones <davej@redhat.com> Tested-by: Marc Dionne <marc.c.dionne@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hayes Wang <hayeswang@realtek.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/realtek/r8169.c6
1 files changed, 1 insertions, 5 deletions
diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index 0dc70c2..06ee243 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -5516,11 +5516,7 @@ static void rtl_slow_event_work(struct rtl8169_private *tp)
if (status & LinkChg)
__rtl8169_check_link_status(dev, tp, tp->mmio_addr, true);
- napi_disable(&tp->napi);
- rtl_irq_disable(tp);
-
- napi_enable(&tp->napi);
- napi_schedule(&tp->napi);
+ rtl_irq_enable_all(tp);
}
static void rtl_task(struct work_struct *work)