context_tracking: New context tracking susbsystem
Create a new subsystem that probes on kernel boundaries
to keep track of the transitions between level contexts
with two basic initial contexts: user or kernel.
This is an abstraction of some RCU code that use such tracking
to implement its userspace extended quiescent state.
We need to pull this up from RCU into this new level of indirection
because this tracking is also going to be used to implement an "on
demand" generic virtual cputime accounting. A necessary step to
shutdown the tick while still accounting the cputime.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
[ paulmck: fix whitespace error and email address. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 0c58952..98faeb3 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -56,7 +56,7 @@
#include <asm/ftrace.h>
#include <asm/percpu.h>
#include <asm/asm.h>
-#include <asm/rcu.h>
+#include <asm/context_tracking.h>
#include <asm/smap.h>
#include <linux/err.h>
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index eff5b8c..65b88a5 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -21,7 +21,7 @@
#include <linux/signal.h>
#include <linux/perf_event.h>
#include <linux/hw_breakpoint.h>
-#include <linux/rcupdate.h>
+#include <linux/context_tracking.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
@@ -1461,7 +1461,7 @@
{
long ret = 0;
- rcu_user_exit();
+ user_exit();
/*
* If we stepped into a sysenter/syscall insn, it trapped in
@@ -1516,7 +1516,7 @@
* or do_notify_resume(), in which case we can be in RCU
* user mode.
*/
- rcu_user_exit();
+ user_exit();
audit_syscall_exit(regs);
@@ -1534,5 +1534,5 @@
if (step || test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, step);
- rcu_user_enter();
+ user_enter();
}
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 29ad351..20ecac1 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -22,6 +22,7 @@
#include <linux/uaccess.h>
#include <linux/user-return-notifier.h>
#include <linux/uprobes.h>
+#include <linux/context_tracking.h>
#include <asm/processor.h>
#include <asm/ucontext.h>
@@ -816,7 +817,7 @@
void
do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
{
- rcu_user_exit();
+ user_exit();
#ifdef CONFIG_X86_MCE
/* notify userspace of pending MCEs */
@@ -840,7 +841,7 @@
if (thread_info_flags & _TIF_USER_RETURN_NOTIFY)
fire_user_return_notifiers();
- rcu_user_enter();
+ user_enter();
}
void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 8276dc6..eb85866 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -55,7 +55,7 @@
#include <asm/i387.h>
#include <asm/fpu-internal.h>
#include <asm/mce.h>
-#include <asm/rcu.h>
+#include <asm/context_tracking.h>
#include <asm/mach_traps.h>