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| author |   Stephen Boyd <sboyd@codeaurora.org> | 2013-07-30 23:09:46 +0100 |
|---|---|---|
| committer |   Russell King <rmk+kernel@arm.linux.org.uk> | 2013-08-01 14:41:39 +0100 |
| commit | 44424c34049f41123a3a8b4853822f47f4ff03a2 (patch) | |
| tree | 98e3b4564c5146e0692826f7940be33d2b645c87 /tools/perf/scripts/python/export-to-postgresql.py | |
| parent | ARM: 7801/1: v6: prevent gcc 4.5 from reordering extended CP15 reads above is_smp() test (diff) | |
| download | linux-dev-44424c34049f41123a3a8b4853822f47f4ff03a2.tar.xz linux-dev-44424c34049f41123a3a8b4853822f47f4ff03a2.zip | |
ARM: 7803/1: Fix deadlock scenario with smp_send_stop()
If one process calls sys_reboot and that process then stops other
CPUs while those CPUs are within a spin_lock() region we can
potentially encounter a deadlock scenario like below.
CPU 0 CPU 1
----- -----
spin_lock(my_lock)
smp_send_stop()
<send IPI> handle_IPI()
disable_preemption/irqs
while(1);
<PREEMPT>
spin_lock(my_lock) <--- Waits forever
We shouldn't attempt to run any other tasks after we send a stop
IPI to a CPU so disable preemption so that this task runs to
completion. We use local_irq_disable() here for cross-arch
consistency with x86.
Reported-by: Sundarajan Srinivasan <sundaraj@codeaurora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions