[PATCH RFC 5/5] rcu: Remove rcu_dereference_raw_notrace since no users
From: Joel Fernandes (Google) <hidden>
Date: 2019-05-24 23:50:11
Also in:
linux-doc, lkml, rcu
Subsystem:
documentation, read-copy update (rcu), the rest · Maintainers:
Jonathan Corbet, "Paul E. McKenney", Frederic Weisbecker, Neeraj Upadhyay, Joel Fernandes, Josh Triplett, Boqun Feng, Uladzislau Rezki, Linus Torvalds
The series removes all users of the API and with this patch, the API itself. Also fix documentation. Signed-off-by: Joel Fernandes (Google) <redacted> --- Documentation/RCU/Design/Requirements/Requirements.html | 6 +++--- include/linux/rcupdate.h | 9 --------- 2 files changed, 3 insertions(+), 12 deletions(-)
diff --git a/Documentation/RCU/Design/Requirements/Requirements.html b/Documentation/RCU/Design/Requirements/Requirements.html
index 5a9238a2883c..9727278893e6 100644
--- a/Documentation/RCU/Design/Requirements/Requirements.html
+++ b/Documentation/RCU/Design/Requirements/Requirements.html@@ -2512,9 +2512,9 @@ disabled across the entire RCU read-side critical section. <p> It is possible to use tracing on RCU code, but tracing itself uses RCU. -For this reason, <tt>rcu_dereference_raw_notrace()</tt> -is provided for use by tracing, which avoids the destructive -recursion that could otherwise ensue. +This is the other reason for using, <tt>rcu_dereference_raw()</tt>, +for use by tracing, which avoids the destructive recursion that could +otherwise ensue. This API is also used by virtualization in some architectures, where RCU readers execute in environments in which tracing cannot be used.
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 922bb6848813..f917a27fc115 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h@@ -472,15 +472,6 @@ static inline void rcu_preempt_sleep_check(void) { } __rcu_dereference_check((p), (c) || rcu_read_lock_sched_held(), \ __rcu) -/* - * The tracing infrastructure traces RCU (we want that), but unfortunately - * some of the RCU checks causes tracing to lock up the system. - * - * The no-tracing version of rcu_dereference_raw() must not call - * rcu_read_lock_held(). - */ -#define rcu_dereference_raw_notrace(p) __rcu_dereference_check((p), 1, __rcu) - /** * rcu_dereference_protected() - fetch RCU pointer when updates prevented * @p: The pointer to read, prior to dereferencing
--
2.22.0.rc1.257.g3120a18244-goog