1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
|
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 7 Mar 2012 21:10:04 +0100
Subject: [PATCH 188/353] net: Use cpu_chill() instead of cpu_relax()
Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=e96b68e550cd4012674a63859f68d242b7dbf31c
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>
---
net/packet/af_packet.c | 5 +++--
net/rds/ib_rdma.c | 3 ++-
2 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index aa12bee4133a..dd652eae83e3 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -63,6 +63,7 @@
#include <linux/if_packet.h>
#include <linux/wireless.h>
#include <linux/kernel.h>
+#include <linux/delay.h>
#include <linux/kmod.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
@@ -668,7 +669,7 @@ static void prb_retire_rx_blk_timer_expired(struct timer_list *t)
if (BLOCK_NUM_PKTS(pbd)) {
while (atomic_read(&pkc->blk_fill_in_prog)) {
/* Waiting for skb_copy_bits to finish... */
- cpu_relax();
+ cpu_chill();
}
}
@@ -930,7 +931,7 @@ 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 0b347f46b2f4..f395f06031bc 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_single_path.h"
#include "ib_mr.h"
@@ -222,7 +223,7 @@ 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();
}
}
|
