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| author | Paul E. McKenney <paulmck@kernel.org> | 2024-02-01 17:10:26 +0300 |
|---|---|---|
| committer | Boqun Feng <boqun.feng@gmail.com> | 2024-02-26 01:27:49 +0300 |
| commit | 0bb11a372fc8d7006b4d0f42a2882939747bdbff (patch) | |
| tree | b87f28feefac58a52950abe40bdf1901bc7b32bb /drivers/fpga/xilinx-selectmap.c | |
| parent | 1612160b91272f5b1596f499584d6064bf5be794 (diff) | |
| download | linux-0bb11a372fc8d7006b4d0f42a2882939747bdbff.tar.xz | |
rcu-tasks: Maintain real-time response in rcu_tasks_postscan()
The current code will scan the entirety of each per-CPU list of exiting
tasks in ->rtp_exit_list with interrupts disabled. This is normally just
fine, because each CPU typically won't have very many tasks in this state.
However, if a large number of tasks block late in do_exit(), these lists
could be arbitrarily long. Low probability, perhaps, but it really
could happen.
This commit therefore occasionally re-enables interrupts while traversing
these lists, inserting a dummy element to hold the current place in the
list. In kernels built with CONFIG_PREEMPT_RT=y, this re-enabling happens
after each list element is processed, otherwise every one-to-two jiffies.
[ paulmck: Apply Frederic Weisbecker feedback. ]
Link: https://lore.kernel.org/all/ZdeI_-RfdLR8jlsm@localhost.localdomain/
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Anna-Maria Behnsen <anna-maria@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Diffstat (limited to 'drivers/fpga/xilinx-selectmap.c')
0 files changed, 0 insertions, 0 deletions