diff options
author | luca abeni <luca.abeni@santannapisa.it> | 2019-03-25 14:15:30 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-02 09:58:56 +0200 |
commit | 245a94a0ffab833292985a8417be093b29ce0e8b (patch) | |
tree | c14efc18da87b46337a8a5f398f5eddad9105904 /fs/nfs | |
parent | 6bf7d3c5c0c5dad650bfc4345ed553c18b69d59e (diff) |
sched/deadline: Correctly handle active 0-lag timers
commit 1b02cd6a2d7f3e2a6a5262887d2cb2912083e42f upstream.
syzbot reported the following warning:
[ ] WARNING: CPU: 4 PID: 17089 at kernel/sched/deadline.c:255 task_non_contending+0xae0/0x1950
line 255 of deadline.c is:
WARN_ON(hrtimer_active(&dl_se->inactive_timer));
in task_non_contending().
Unfortunately, in some cases (for example, a deadline task
continuosly blocking and waking immediately) it can happen that
a task blocks (and task_non_contending() is called) while the
0-lag timer is still active.
In this case, the safest thing to do is to immediately decrease
the running bandwidth of the task, without trying to re-arm the 0-lag timer.
Signed-off-by: luca abeni <luca.abeni@santannapisa.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: chengjian (D) <cj.chengjian@huawei.com>
Link: https://lkml.kernel.org/r/20190325131530.34706-1-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/nfs')
0 files changed, 0 insertions, 0 deletions