From: Oleg Nesterov <oleg@redhat.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Rik van Riel <riel@redhat.com>, Tejun Heo <tj@kernel.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 0/6] stop_machine: cleanups, fix, remove lglock
Date: Tue, 21 Jul 2015 21:22:19 +0200 [thread overview]
Message-ID: <20150721192219.GA31150@redhat.com> (raw)
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(-)
next reply other threads:[~2015-07-21 19:24 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-21 19:22 Oleg Nesterov [this message]
2015-07-21 19:22 ` [PATCH v2 1/6] stop_machine: move cpu_stopper_task and stop_cpus_work into struct cpu_stopper Oleg Nesterov
2015-07-21 19:22 ` [PATCH v2 2/6] stop_machine: don't do for_each_cpu() twice in queue_stop_cpus_work() Oleg Nesterov
2015-07-21 19:22 ` [PATCH v2 3/6] stop_machine: unexport __stop_machine() Oleg Nesterov
2015-07-21 19:22 ` [PATCH v2 4/6] stop_machine: use cpu_stop_fn_t where possible Oleg Nesterov
2015-07-21 19:22 ` [PATCH v2 5/6] stop_machine: cpu_stop_park() should remove cpu_stop_work's from list Oleg Nesterov
2015-07-21 19:22 ` [PATCH v2 6/6] stop_machine: kill stop_cpus_lock and lg_double_lock/unlock() Oleg Nesterov
2015-07-30 21:55 ` Peter Zijlstra
2015-07-31 11:12 ` Peter Zijlstra
2015-07-31 14:17 ` Peter Zijlstra
2015-08-03 14:58 ` Oleg Nesterov
2015-08-01 10:57 ` Oleg Nesterov
2015-08-01 22:36 ` Peter Zijlstra
2015-08-03 14:58 ` Oleg Nesterov
2015-07-30 17:34 ` [PATCH v2 0/6] stop_machine: cleanups, fix, remove lglock Peter Zijlstra
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