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authorThomas Gleixner <tglx@linutronix.de>2012-03-07 21:10:04 +0100
committerClark Williams <williams@redhat.com>2012-03-07 16:15:18 -0600
commit4d787e8704b7e563c87fd683c55ed4945d633f79 (patch)
tree801dc85d21e4c2c730fe41d41b693eaa35b168fd
parent0a466c6154c14150a1b2d42612a1c8a8e9a639de (diff)
net: Use cpu_chill() instead of cpu_relax()
Retry loops on RT might loop forever when the modifying side was preempted. Use cpu_chill() instead of cpu_relax() to let the system make progress. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable-rt@vger.kernel.org
-rw-r--r--net/packet/af_packet.c5
-rw-r--r--net/rds/ib_rdma.c3
2 files changed, 5 insertions, 3 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index d9d4970b9b07..ed8ef1eb2569 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -89,6 +89,7 @@
#include <linux/virtio_net.h>
#include <linux/errqueue.h>
#include <linux/net_tstamp.h>
+#include <linux/delay.h>
#ifdef CONFIG_INET
#include <net/inet_common.h>
@@ -673,7 +674,7 @@ static void prb_retire_rx_blk_timer_expired(unsigned long data)
if (BLOCK_NUM_PKTS(pbd)) {
while (atomic_read(&pkc->blk_fill_in_prog)) {
/* Waiting for skb_copy_bits to finish... */
- cpu_relax();
+ cpu_chill();
}
}
@@ -928,7 +929,7 @@ static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
if (!(status & TP_STATUS_BLK_TMO)) {
while (atomic_read(&pkc->blk_fill_in_prog)) {
/* Waiting for skb_copy_bits to finish... */
- cpu_relax();
+ cpu_chill();
}
}
prb_close_block(pkc, pbd, po, status);
diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c
index e8fdb172adbb..5a44c6e77cd8 100644
--- a/net/rds/ib_rdma.c
+++ b/net/rds/ib_rdma.c
@@ -34,6 +34,7 @@
#include <linux/slab.h>
#include <linux/rculist.h>
#include <linux/llist.h>
+#include <linux/delay.h>
#include "rds.h"
#include "ib.h"
@@ -286,7 +287,7 @@ static inline void wait_clean_list_grace(void)
for_each_online_cpu(cpu) {
flag = &per_cpu(clean_list_grace, cpu);
while (test_bit(CLEAN_LIST_BUSY_BIT, flag))
- cpu_relax();
+ cpu_chill();
}
}