https://github.com/torvalds/linux
Revision 093e5840ae76f1082633503964d035f40ed0216d authored by Sebastian Andrzej Siewior on 21 December 2015, 17:17:10 UTC, committed by Ingo Molnar on 06 January 2016, 10:01:07 UTC
In the following commit: 7675104990ed ("sched: Implement lockless wake-queues") we gained lockless wake-queues. The -RT kernel managed to lockup itself with those. There could be multiple attempts for task X to enqueue it for a wakeup _even_ if task X is already running. The reason is that task X could be runnable but not yet on CPU. The the task performing the wakeup did not leave the CPU it could performe multiple wakeups. With the proper timming task X could be running and enqueued for a wakeup. If this happens while X is performing a fork() then its its child will have a !NULL `wake_q` member copied. This is not a problem as long as the child task does not participate in lockless wakeups :) Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 7675104990ed ("sched: Implement lockless wake-queues") Link: http://lkml.kernel.org/r/20151221171710.GA5499@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Tip revision: 093e5840ae76f1082633503964d035f40ed0216d authored by Sebastian Andrzej Siewior on 21 December 2015, 17:17:10 UTC
sched/core: Reset task's lockless wake-queues on fork()
sched/core: Reset task's lockless wake-queues on fork()
Tip revision: 093e584
File | Mode | Size |
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Makefile | -rw-r--r-- | 936 bytes |
datagram.c | -rw-r--r-- | 18.6 KB |
dev.c | -rw-r--r-- | 193.9 KB |
dev_addr_lists.c | -rw-r--r-- | 20.8 KB |
dev_ioctl.c | -rw-r--r-- | 12.6 KB |
drop_monitor.c | -rw-r--r-- | 9.7 KB |
dst.c | -rw-r--r-- | 11.3 KB |
ethtool.c | -rw-r--r-- | 48.1 KB |
fib_rules.c | -rw-r--r-- | 18.1 KB |
filter.c | -rw-r--r-- | 50.5 KB |
flow.c | -rw-r--r-- | 12.4 KB |
flow_dissector.c | -rw-r--r-- | 22.8 KB |
gen_estimator.c | -rw-r--r-- | 8.8 KB |
gen_stats.c | -rw-r--r-- | 9.4 KB |
link_watch.c | -rw-r--r-- | 5.5 KB |
lwtunnel.c | -rw-r--r-- | 5.3 KB |
neighbour.c | -rw-r--r-- | 78.3 KB |
net-procfs.c | -rw-r--r-- | 9.6 KB |
net-sysfs.c | -rw-r--r-- | 37.0 KB |
net-sysfs.h | -rw-r--r-- | 368 bytes |
net-traces.c | -rw-r--r-- | 918 bytes |
net_namespace.c | -rw-r--r-- | 22.7 KB |
netclassid_cgroup.c | -rw-r--r-- | 2.8 KB |
netevent.c | -rw-r--r-- | 2.0 KB |
netpoll.c | -rw-r--r-- | 19.4 KB |
netprio_cgroup.c | -rw-r--r-- | 6.5 KB |
pktgen.c | -rw-r--r-- | 96.7 KB |
ptp_classifier.c | -rw-r--r-- | 7.2 KB |
request_sock.c | -rw-r--r-- | 5.3 KB |
rtnetlink.c | -rw-r--r-- | 84.6 KB |
scm.c | -rw-r--r-- | 7.7 KB |
secure_seq.c | -rw-r--r-- | 4.1 KB |
skbuff.c | -rw-r--r-- | 111.1 KB |
sock.c | -rw-r--r-- | 74.0 KB |
sock_diag.c | -rw-r--r-- | 7.8 KB |
stream.c | -rw-r--r-- | 5.2 KB |
sysctl_net_core.c | -rw-r--r-- | 10.2 KB |
timestamping.c | -rw-r--r-- | 2.1 KB |
tso.c | -rw-r--r-- | 2.3 KB |
utils.c | -rw-r--r-- | 8.2 KB |
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