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
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Makefile.asm-generic | -rw-r--r-- | 683 bytes |
Makefile.build | -rw-r--r-- | 13.4 KB |
Makefile.clean | -rw-r--r-- | 2.8 KB |
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Makefile.extrawarn | -rw-r--r-- | 2.4 KB |
Makefile.fwinst | -rw-r--r-- | 2.0 KB |
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Makefile.help | -rw-r--r-- | 68 bytes |
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Makefile.lib | -rw-r--r-- | 14.0 KB |
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Makefile.modinst | -rw-r--r-- | 1.2 KB |
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Makefile.modsign | -rw-r--r-- | 1005 bytes |
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asn1_compiler.c | -rw-r--r-- | 35.5 KB |
bloat-o-meter | -rwxr-xr-x | 1.9 KB |
bootgraph.pl | -rwxr-xr-x | 6.3 KB |
check-lc_ctype.c | -rw-r--r-- | 201 bytes |
check_extable.sh | -rwxr-xr-x | 4.9 KB |
checkincludes.pl | -rwxr-xr-x | 1.8 KB |
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checkpatch.pl | -rwxr-xr-x | 169.8 KB |
checkstack.pl | -rwxr-xr-x | 5.4 KB |
checksyscalls.sh | -rwxr-xr-x | 5.6 KB |
checkversion.pl | -rwxr-xr-x | 1.9 KB |
cleanfile | -rwxr-xr-x | 3.4 KB |
cleanpatch | -rwxr-xr-x | 5.0 KB |
coccicheck | -rwxr-xr-x | 4.7 KB |
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decode_stacktrace.sh | -rwxr-xr-x | 3.1 KB |
decodecode | -rwxr-xr-x | 2.1 KB |
depmod.sh | -rwxr-xr-x | 1.7 KB |
diffconfig | -rwxr-xr-x | 3.7 KB |
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export_report.pl | -rwxr-xr-x | 4.5 KB |
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extract-module-sig.pl | -rwxr-xr-x | 3.6 KB |
extract-sys-certs.pl | -rwxr-xr-x | 3.3 KB |
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gcc-goto.sh | -rwxr-xr-x | 495 bytes |
gcc-ld | -rwxr-xr-x | 676 bytes |
gcc-version.sh | -rwxr-xr-x | 822 bytes |
gcc-x86_32-has-stack-protector.sh | -rwxr-xr-x | 184 bytes |
gcc-x86_64-has-stack-protector.sh | -rwxr-xr-x | 200 bytes |
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headers_check.pl | -rwxr-xr-x | 3.6 KB |
headers_install.sh | -rwxr-xr-x | 1.3 KB |
kallsyms.c | -rw-r--r-- | 16.7 KB |
kernel-doc | -rwxr-xr-x | 76.0 KB |
kernel-doc-xml-ref | -rwxr-xr-x | 4.2 KB |
ld-version.sh | -rwxr-xr-x | 205 bytes |
link-vmlinux.sh | -rwxr-xr-x | 5.8 KB |
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markup_oops.pl | -rwxr-xr-x | 8.1 KB |
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mkmakefile | -rwxr-xr-x | 1.2 KB |
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module-common.lds | -rw-r--r-- | 833 bytes |
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recordmcount.pl | -rwxr-xr-x | 17.8 KB |
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sign-file.c | -rwxr-xr-x | 8.1 KB |
sortextable.c | -rw-r--r-- | 7.6 KB |
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stackdelta | -rwxr-xr-x | 1.8 KB |
stackusage | -rwxr-xr-x | 759 bytes |
tags.sh | -rwxr-xr-x | 10.6 KB |
unifdef.c | -rw-r--r-- | 34.8 KB |
ver_linux | -rwxr-xr-x | 3.9 KB |
xen-hypercalls.sh | -rw-r--r-- | 351 bytes |
xz_wrap.sh | -rwxr-xr-x | 562 bytes |
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