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 12/14] trace: correct off by one while recording the trace-event
Date: Tue, 12 Jul 2016 12:48:11 -0400 [thread overview]
Message-ID: <20160712164819.659538786@goodmis.org> (raw)
In-Reply-To: 20160712164759.154249453@goodmis.org
[-- Attachment #1: 0012-trace-correct-off-by-one-while-recording-the-trace-e.patch --]
[-- Type: text/plain, Size: 1205 bytes --]
3.14.72-rt76-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 1ee19a24cc5f..73a9f766e904 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -555,6 +555,9 @@ 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 16:48 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-12 16:47 [PATCH RT 00/14] Linux 3.14.72-rt76-rc1 Steven Rostedt
2016-07-12 16:48 ` [PATCH RT 01/14] kvm, rt: change async pagefault code locking for PREEMPT_RT Steven Rostedt
2016-07-12 16:48 ` [PATCH RT 02/14] mm/zsmalloc: Use get/put_cpu_light in zs_map_object()/zs_unmap_object() Steven Rostedt
2016-07-12 16:48 ` [PATCH RT 03/14] net: dev: always take qdiscs busylock in __dev_xmit_skb() Steven Rostedt
2016-07-12 16:48 ` [PATCH RT 04/14] list_bl: fixup bogus lockdep warning Steven Rostedt
2016-07-12 16:48 ` [PATCH RT 05/14] ARM: imx: always use TWD on IMX6Q Steven Rostedt
2016-07-12 16:48 ` [PATCH RT 06/14] perf/x86/intel/rapl: Make PMU lock raw Steven Rostedt
2016-07-12 16:48 ` [PATCH RT 07/14] sched,preempt: Fix preempt_count manipulations Steven Rostedt
2016-07-12 16:48 ` [PATCH RT 08/14] kernel/printk: Dont try to print from IRQ/NMI region Steven Rostedt
2016-07-12 16:48 ` [PATCH RT 09/14] arm: lazy preempt: correct resched condition Steven Rostedt
2016-07-12 16:48 ` [PATCH RT 10/14] locallock: add local_lock_on() Steven Rostedt
2016-07-12 16:48 ` [PATCH RT 11/14] mm: perform lru_add_drain_all() remotely Steven Rostedt
2016-07-12 16:48 ` Steven Rostedt [this message]
2016-07-12 16:48 ` [PATCH RT 13/14] x86: Fix an RT MCE crash Steven Rostedt
2016-07-12 16:48 ` [PATCH RT 14/14] Linux 3.14.72-rt76-rc1 Steven Rostedt
2016-07-12 23:21 ` Linux 3.14.72-rt76-rc2 Steven Rostedt
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