[PATCH RT 1/4] Revert "net: Properly annotate the try-lock for the seqlock"

Steven Rostedt
2020-12-11T22:41:03Z

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

This reverts commit 3971227b5af04e6c34ef7b47b2ebe941727563a0.

Link: https://lore.kernel.org/r/20201116171958.2opbksmgbznrjxu2@linutronix.de

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
include/linux/seqlock.h | 9 +++++++++
include/net/sch_generic.h | 10 +---------
2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index f390293974ea..e5207897c33e 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -489,6 +489,15 @@ static inline void write_seqlock(seqlock_t *sl)
__raw_write_seqcount_begin(&sl->seqcount);
}

+static inline int try_write_seqlock(seqlock_t *sl)
+{
+ if (spin_trylock(&sl->lock)) {
+ __raw_write_seqcount_begin(&sl->seqcount);
+ return 1;
+ }
+ return 0;
+}
+
static inline void write_sequnlock(seqlock_t *sl)
{
__raw_write_seqcount_end(&sl->seqcount);
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 112d2dca8b08..e6afb4b9cede 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -168,16 +168,8 @@ static inline bool qdisc_run_begin(struct Qdisc *qdisc)
return false;
}
#ifdef CONFIG_PREEMPT_RT
- if (spin_trylock(&qdisc->running.lock)) {
- seqcount_t *s = &qdisc->running.seqcount;
- /*
- * Variant of write_seqcount_t_begin() telling lockdep that a
- * trylock was attempted.
- */
- __raw_write_seqcount_begin(s);
- seqcount_acquire(&s->dep_map, 0, 1, _RET_IP_);
+ if (try_write_seqlock(&qdisc->running))
return true;
- }
return false;
#else
/* Variant of write_seqcount_begin() telling lockdep a trylock
--
2.29.2