lkml.org 
[lkml]   [2017]   [Oct]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH tip/core/rcu 3/4] rcu: Turn off tracing before dumping trace
Date
Currently, RCU allows tracing to continue when it automatically does
ftrace_dump() after detecting an error condition, which can result in
excessively large traces and lost trace events. This commit therefore
does a tracing_off() before any of these ftrace_dump() calls.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/rcu/rcu.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index e4b43fef89f5..b8729eb09a5d 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -220,8 +220,10 @@ do { \
static atomic_t ___rfd_beenhere = ATOMIC_INIT(0); \
\
if (!atomic_read(&___rfd_beenhere) && \
- !atomic_xchg(&___rfd_beenhere, 1)) \
+ !atomic_xchg(&___rfd_beenhere, 1)) { \
+ tracing_off(); \
ftrace_dump(oops_dump_mode); \
+ } \
} while (0)

void rcu_early_boot_tests(void);
--
2.5.2
\
 
 \ /
  Last update: 2017-10-04 23:53    [W:0.045 / U:0.444 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site