[ANNOUNCE] 4.6.7-rt12
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2016-09-08 19:00:34
Also in:
lkml
Subsystem:
filesystems (vfs and infrastructure), networking [general], networking [ipv4/ipv6], networking [tcp], the rest · Maintainers:
Alexander Viro, Christian Brauner, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Neal Cardwell, Linus Torvalds
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); }