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Subject[PATCH v2 0/6] stop_machine: cleanups, fix, remove lglock
Hello,

Let me resend this. The only change in v2 is that I rediffed this
series against v4.2-rc3.

5/6 patch fixes the bug, I think. Say, stop_one_cpu(X) can race with
_cpu_down(X)->stop_machine() so that the kernel will crash if this
CPU X becomes online again. The window after cpu_stopper_thread()
returns and before smpboot_thread() calls ->park() is tiny, but still
this is possible afaics. But see the changelog in 6/6, I think we
should turn this cpu_stop_signal_done() into BUG() later.

6/6 removes lglock from kernel/stop_machine.c.

Peter, Rik, what do you think ?

Oleg.

include/linux/lglock.h | 5 --
include/linux/stop_machine.h | 28 ++------
kernel/cpu.c | 2 +-
kernel/locking/lglock.c | 22 ------
kernel/stop_machine.c | 162 ++++++++++++++++++++++++------------------
5 files changed, 98 insertions(+), 121 deletions(-)



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