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| author | Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | 2016-11-03 10:29:28 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-03-12 06:37:26 +0100 |
| commit | c0ef1f537a9728a91475f8f73cf8b5764e7a9848 (patch) | |
| tree | 5c13f17f5ab5b26fdeda83ceaefdc91859e93eaa /kernel/trace/trace_functions_graph.c | |
| parent | ea240cfed99bda8fc1774801cb9da355e66dc7e1 (diff) | |
Fix: Disable sys_membarrier when nohz_full is enabled
commit 907565337ebf998a68cb5c5b2174ce5e5da065eb upstream.
Userspace applications should be allowed to expect the membarrier system
call with MEMBARRIER_CMD_SHARED command to issue memory barriers on
nohz_full CPUs, but synchronize_sched() does not take those into
account.
Given that we do not want unrelated processes to be able to affect
real-time sensitive nohz_full CPUs, simply return ENOSYS when membarrier
is invoked on a kernel with enabled nohz_full CPUs.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Lai Jiangshan <jiangshanlai@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/trace/trace_functions_graph.c')
0 files changed, 0 insertions, 0 deletions