pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion
Wei Wang reported seeing priority inversion caused latencies
caused by contention on pmsg_lock, and suggested it be switched
to a rt_mutex.
I was initially hesitant this would help, as the tasks in that
trace all seemed to be SCHED_NORMAL, so the benefit would be
limited to only nice boosting.
However, another similar issue was raised where the priority
inversion was seen did involve a blocked RT task so it is clear
this would be helpful in that case.
Cc: Wei Wang <email@example.com>
Cc: Midas Chien<firstname.lastname@example.org>
Cc: Connor O'Brien <email@example.com>
Cc: Kees Cook <firstname.lastname@example.org>
Cc: Anton Vorontsov <email@example.com>
Cc: Colin Cross <firstname.lastname@example.org>
Cc: Tony Luck <email@example.com>
Fixes: 9d5438f462ab ("pstore: Add pmsg - user-space accessible pstore object")
Reported-by: Wei Wang <firstname.lastname@example.org>
Signed-off-by: John Stultz <email@example.com>
Signed-off-by: Kees Cook <firstname.lastname@example.org>
1 file changed