From: Frederic Weisbecker <fweis...@gmail.com>
Add syscall hooks to notify syscall entry and exit on
CPUs running in adative nohz mode.
Signed-off-by: Frederic Weisbecker <fweis...@gmail.com>
Cc: Alessio Igor Bogani <abog...@kernel.org>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Avi Kivity <a...@redhat.com>
Cc: Chris Metcalf <cmetc...@tilera.com>
Cc: Christoph Lameter <c...@linux.com>
Cc: Daniel Lezcano <daniel.lezc...@linaro.org>
Cc: Geoff Levand <ge...@infradead.org>
Cc: Gilad Ben Yossef <gi...@benyossef.com>
Cc: Hakan Akkan <hakanak...@gmail.com>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Kevin Hilman <khil...@ti.com>
Cc: Max Krasnyansky <m...@qualcomm.com>
Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Stephen Hemminger <shemmin...@vyatta.com>
Cc: Steven Rostedt <rost...@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporat...@gmail.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Signed-off-by: Steven Rostedt <rost...@goodmis.org>
---
arch/x86/kernel/ptrace.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index b00b33a..9c18e1e 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -22,6 +22,7 @@
#include <linux/perf_event.h>
#include <linux/hw_breakpoint.h>
#include <linux/rcupdate.h>
+#include <linux/tick.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
@@ -1461,6 +1462,10 @@ long syscall_trace_enter(struct pt_regs *regs)
{
long ret = 0;
+ /* Notify nohz task syscall early so the rest can use rcu */
+ /* (SDR: Does the rcu_user_exit() make this obsolete?) */
+ tick_nohz_enter_kernel();
+
rcu_user_exit();
/*
@@ -1528,4 +1533,10 @@ void syscall_trace_leave(struct pt_regs *regs)
tracehook_report_syscall_exit(regs, step);
rcu_user_enter();
+ /*
+ * Notify nohz task exit syscall at last so the rest can
+ * use rcu.
+ * (SDR: does the above make this obsolete?)
+ */
+ tick_nohz_exit_kernel();
}
--
1.7.10.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
