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authorLinus Torvalds <torvalds@linux-foundation.org>2013-02-19 18:19:48 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-19 18:19:48 -0800
commitd652e1eb8e7b739fccbfb503a3da3e9f640fbf3d (patch)
tree55ab77bad0cbb045eac0b84b80d63f88f1ae09e6 /kernel/context_tracking.c
parent8f55cea410dbc56114bb71a3742032070c8108d0 (diff)
parent77852fea6e2442a0e654a9292060489895de18c7 (diff)
downloadlinux-sh-d652e1eb8e7b739fccbfb503a3da3e9f640fbf3d.tar.gz
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar: "Main changes: - scheduler side full-dynticks (user-space execution is undisturbed and receives no timer IRQs) preparation changes that convert the cputime accounting code to be full-dynticks ready, from Frederic Weisbecker. - Initial sched.h split-up changes, by Clark Williams - select_idle_sibling() performance improvement by Mike Galbraith: " 1 tbench pair (worst case) in a 10 core + SMT package: pre 15.22 MB/sec 1 procs post 252.01 MB/sec 1 procs " - sched_rr_get_interval() ABI fix/change. We think this detail is not used by apps (so it's not an ABI in practice), but lets keep it under observation. - misc RT scheduling cleanups, optimizations" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) sched/rt: Add <linux/sched/rt.h> header to <linux/init_task.h> cputime: Remove irqsave from seqlock readers sched, powerpc: Fix sched.h split-up build failure cputime: Restore CPU_ACCOUNTING config defaults for PPC64 sched/rt: Move rt specific bits into new header file sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice sched: Move sched.h sysctl bits into separate header sched: Fix signedness bug in yield_to() sched: Fix select_idle_sibling() bouncing cow syndrome sched/rt: Further simplify pick_rt_task() sched/rt: Do not account zero delta_exec in update_curr_rt() cputime: Safely read cputime of full dynticks CPUs kvm: Prepare to add generic guest entry/exit callbacks cputime: Use accessors to read task cputime stats cputime: Allow dynamic switch between tick/virtual based cputime accounting cputime: Generic on-demand virtual cputime accounting cputime: Move default nsecs_to_cputime() to jiffies based cputime file cputime: Librarize per nsecs resolution cputime definitions cputime: Avoid multiplication overflow on utime scaling context_tracking: Export context state for generic vtime ... Fix up conflict in kernel/context_tracking.c due to comment additions.
Diffstat (limited to 'kernel/context_tracking.c')
-rw-r--r--kernel/context_tracking.c43
1 files changed, 25 insertions, 18 deletions
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index d566aba7e801..65349f07b878 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -15,26 +15,13 @@
*/
#include <linux/context_tracking.h>
+#include <linux/kvm_host.h>
#include <linux/rcupdate.h>
#include <linux/sched.h>
-#include <linux/percpu.h>
#include <linux/hardirq.h>
+#include <linux/export.h>
-struct context_tracking {
- /*
- * When active is false, probes are unset in order
- * to minimize overhead: TIF flags are cleared
- * and calls to user_enter/exit are ignored. This
- * may be further optimized using static keys.
- */
- bool active;
- enum {
- IN_KERNEL = 0,
- IN_USER,
- } state;
-};
-
-static DEFINE_PER_CPU(struct context_tracking, context_tracking) = {
+DEFINE_PER_CPU(struct context_tracking, context_tracking) = {
#ifdef CONFIG_CONTEXT_TRACKING_FORCE
.active = true,
#endif
@@ -70,7 +57,6 @@ void user_enter(void)
local_irq_save(flags);
if (__this_cpu_read(context_tracking.active) &&
__this_cpu_read(context_tracking.state) != IN_USER) {
- __this_cpu_write(context_tracking.state, IN_USER);
/*
* At this stage, only low level arch entry code remains and
* then we'll run in userspace. We can assume there won't be
@@ -78,7 +64,9 @@ void user_enter(void)
* user_exit() or rcu_irq_enter(). Let's remove RCU's dependency
* on the tick.
*/
+ vtime_user_enter(current);
rcu_user_enter();
+ __this_cpu_write(context_tracking.state, IN_USER);
}
local_irq_restore(flags);
}
@@ -104,16 +92,35 @@ void user_exit(void)
local_irq_save(flags);
if (__this_cpu_read(context_tracking.state) == IN_USER) {
- __this_cpu_write(context_tracking.state, IN_KERNEL);
/*
* We are going to run code that may use RCU. Inform
* RCU core about that (ie: we may need the tick again).
*/
rcu_user_exit();
+ vtime_user_exit(current);
+ __this_cpu_write(context_tracking.state, IN_KERNEL);
}
local_irq_restore(flags);
}
+void guest_enter(void)
+{
+ if (vtime_accounting_enabled())
+ vtime_guest_enter(current);
+ else
+ __guest_enter();
+}
+EXPORT_SYMBOL_GPL(guest_enter);
+
+void guest_exit(void)
+{
+ if (vtime_accounting_enabled())
+ vtime_guest_exit(current);
+ else
+ __guest_exit();
+}
+EXPORT_SYMBOL_GPL(guest_exit);
+
/**
* context_tracking_task_switch - context switch the syscall callbacks