From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Carsten Emde <C.Emde@osadl.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
John Kacur <jkacur@redhat.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
<stable-rt@vger.kernel.org>
Subject: [PATCH RT 6/8] trace: correct off by one while recording the trace-event
Date: Tue, 12 Jul 2016 12:57:55 -0400 [thread overview]
Message-ID: <20160712165802.763646959@goodmis.org> (raw)
In-Reply-To: 20160712165749.741663758@goodmis.org
[-- Attachment #1: 0006-trace-correct-off-by-one-while-recording-the-trace-e.patch --]
[-- Type: text/plain, Size: 1207 bytes --]
3.10.102-rt113-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Trace events like raw_syscalls show always a preempt code of one. The
reason is that on PREEMPT kernels rcu_read_lock_sched_notrace()
increases the preemption counter and the function recording the counter
is caller within the RCU section.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ Changed this to upstream version. See commit e947841c0dce ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
include/trace/ftrace.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index dbb47418df81..f30e85b675e8 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -526,6 +526,9 @@ ftrace_raw_event_##call(void *__data, proto) \
\
local_save_flags(irq_flags); \
pc = preempt_count(); \
+ /* Account for tracepoint preempt disable */ \
+ if (IS_ENABLED(CONFIG_PREEMPT)) \
+ pc--; \
\
__data_size = ftrace_get_offsets_##call(&__data_offsets, args); \
\
--
2.8.1
next prev parent reply other threads:[~2016-07-12 16:58 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-12 16:57 [PATCH RT 0/8] Linux 3.10.102-rt113-rc1 Steven Rostedt
2016-07-12 16:57 ` [PATCH RT 1/8] kvm, rt: change async pagefault code locking for PREEMPT_RT Steven Rostedt
2016-07-12 16:57 ` [PATCH RT 2/8] net: dev: always take qdiscs busylock in __dev_xmit_skb() Steven Rostedt
2016-07-12 16:57 ` [PATCH RT 3/8] list_bl: fixup bogus lockdep warning Steven Rostedt
2016-07-12 16:57 ` [PATCH RT 4/8] kernel/printk: Dont try to print from IRQ/NMI region Steven Rostedt
2016-07-12 16:57 ` [PATCH RT 5/8] arm: lazy preempt: correct resched condition Steven Rostedt
2016-07-12 16:57 ` Steven Rostedt [this message]
2016-07-12 16:57 ` [PATCH RT 7/8] x86: Fix an RT MCE crash Steven Rostedt
2016-07-12 16:57 ` [PATCH RT 8/8] Linux 3.10.102-rt113-rc1 Steven Rostedt
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