]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
ftrace: Add comment to why rcu_dereference_sched() is open coded
authorSteven Rostedt (VMware) <rostedt@goodmis.org>
Wed, 5 Feb 2020 07:17:57 +0000 (02:17 -0500)
committerSteven Rostedt (VMware) <rostedt@goodmis.org>
Wed, 5 Feb 2020 22:15:57 +0000 (17:15 -0500)
commit16052dd5bdfa16dbe18d8c1d4cde2ddab9d23177
tree1e1a0196c967b872befb00d64b839492bf77c54b
parentfd0e6852c407dd9aefc594f54ddcc21d84803d3b
ftrace: Add comment to why rcu_dereference_sched() is open coded

Because the function graph tracer can execute in sections where RCU is not
"watching", the rcu_dereference_sched() for the has needs to be open coded.
This is fine because the RCU "flavor" of the ftrace hash is protected by
its own RCU handling (it does its own little synchronization on every CPU
and does not rely on RCU sched).

Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
kernel/trace/trace.h