Dear RT folks!
I'm pleased to announce the v4.6.7-rt12 patch set.
Changes since v4.6.7-rt11:
- The update to v4.6.7-rt11 introduced a performance regression
especially visible when compiling a kernel on /dev/shm. It is fixed
by invoking less often the "chill" function. Reported by Joakim
Hernberg.
- We had a fix in v3.12.8-rt11 for ip_send_unicast_reply() which I
dropped in v3.18.8 based -RT due code change and I assumed the need
for extra serialization is no longer required. As it turns out it is
still required :)
- While looking around a similar serialisation might be required in
icmp_sk(). No crash has been observed, this is just precaution.
Known issues
- CPU hotplug got a little better but can deadlock.
The delta patch against 4.6.7-rt11 is appended below and can be found here:
https://cdn.kernel.org/pub/linux/kernel/projects/rt/4.6/incr/patch-4.6.7-rt11-rt12.patch.xz
You can get this release via the git tree at:
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git v4.6.7-rt12
The RT patch against 4.6.5 can be found here:
https://cdn.kernel.org/pub/linux/kernel/projects/rt/4.6/patch-4.6.7-rt12.patch.xz
The split quilt queue is available at:
https://cdn.kernel.org/pub/linux/kernel/projects/rt/4.6/patches-4.6.7-rt12.tar.xz
Sebastian
diff --git a/fs/dcache.c b/fs/dcache.c
index 32c0bfecc920..aa418c1bdcb5 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -40,6 +40,8 @@
#include <linux/ratelimit.h>
#include <linux/list_lru.h>
#include <linux/kasan.h>
+#include <linux/sched/rt.h>
+#include <linux/sched/deadline.h>
#include "internal.h"
#include "mount.h"
@@ -748,6 +750,8 @@ static inline bool fast_dput(struct dentry *dentry)
*/
void dput(struct dentry *dentry)
{
+ struct dentry *parent;
+
if (unlikely(!dentry))
return;
@@ -784,14 +788,17 @@ void dput(struct dentry *dentry)
return;
kill_it:
- dentry = dentry_kill(dentry);
- if (dentry) {
+ parent = dentry_kill(dentry);
+ if (parent) {
int r;
- /* the task with the highest priority won't schedule */
- r = cond_resched();
- if (!r)
- cpu_chill();
+ if (parent == dentry) {
+ /* the task with the highest priority won't schedule */
+ r = cond_resched();
+ if (!r && (rt_task(current) || dl_task(current)))
+ cpu_chill();
+ } else
+ dentry = parent;
goto repeat;
}
}
diff --git a/localversion-rt b/localversion-rt
index 05c35cb58077..6e44e540b927 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt11
+-rt12
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index c1f1d5030d37..63731fd6af3e 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -78,6 +78,7 @@
#include <linux/string.h>
#include <linux/netfilter_ipv4.h>
#include <linux/slab.h>
+#include <linux/locallock.h>
#include <net/snmp.h>
#include <net/ip.h>
#include <net/route.h>
@@ -205,6 +206,8 @@ static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
*
* On SMP we have one ICMP socket per-cpu.
*/
+static DEFINE_LOCAL_IRQ_LOCK(icmp_sk_lock);
+
static struct sock *icmp_sk(struct net *net)
{
return *this_cpu_ptr(net->ipv4.icmp_sk);
@@ -216,12 +219,14 @@ static inline struct sock *icmp_xmit_lock(struct net *net)
local_bh_disable();
+ local_lock(icmp_sk_lock);
sk = icmp_sk(net);
if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
/* This can happen if the output path signals a
* dst_link_failure() for an outgoing ICMP packet.
*/
+ local_unlock(icmp_sk_lock);
local_bh_enable();
return NULL;
}
@@ -231,6 +236,7 @@ static inline struct sock *icmp_xmit_lock(struct net *net)
static inline void icmp_xmit_unlock(struct sock *sk)
{
spin_unlock_bh(&sk->sk_lock.slock);
+ local_unlock(icmp_sk_lock);
}
int sysctl_icmp_msgs_per_sec __read_mostly = 1000;
@@ -359,6 +365,7 @@ static void icmp_push_reply(struct icmp_bxm *icmp_param,
struct sock *sk;
struct sk_buff *skb;
+ local_lock(icmp_sk_lock);
sk = icmp_sk(dev_net((*rt)->dst.dev));
if (ip_append_data(sk, fl4, icmp_glue_bits, icmp_param,
icmp_param->data_len+icmp_param->head_len,
@@ -381,6 +388,7 @@ static void icmp_push_reply(struct icmp_bxm *icmp_param,
skb->ip_summed = CHECKSUM_NONE;
ip_push_pending_frames(sk, fl4);
}
+ local_unlock(icmp_sk_lock);
}
/*
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index ad450509029b..c5521d1f1263 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -62,6 +62,7 @@
#include <linux/init.h>
#include <linux/times.h>
#include <linux/slab.h>
+#include <linux/locallock.h>
#include <net/net_namespace.h>
#include <net/icmp.h>
@@ -565,6 +566,7 @@ void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb)
}
EXPORT_SYMBOL(tcp_v4_send_check);
+static DEFINE_LOCAL_IRQ_LOCK(tcp_sk_lock);
/*
* This routine will send an RST to the other tcp.
*
@@ -689,10 +691,13 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
offsetof(struct inet_timewait_sock, tw_bound_dev_if));
arg.tos = ip_hdr(skb)->tos;
+
+ local_lock(tcp_sk_lock);
ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
skb, &TCP_SKB_CB(skb)->header.h4.opt,
ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
&arg, arg.iov[0].iov_len);
+ local_unlock(tcp_sk_lock);
TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
@@ -774,10 +779,12 @@ static void tcp_v4_send_ack(struct net *net,
if (oif)
arg.bound_dev_if = oif;
arg.tos = tos;
+ local_lock(tcp_sk_lock);
ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
skb, &TCP_SKB_CB(skb)->header.h4.opt,
ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
&arg, arg.iov[0].iov_len);
+ local_unlock(tcp_sk_lock);
TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
}
--
To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
