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authorFrederic Weisbecker <fweisbec@gmail.com>2013-07-12 19:02:30 +0200
committerFrederic Weisbecker <fweisbec@gmail.com>2013-08-13 00:40:44 +0200
commit2d854e5738cded368a0759f85b1197f5c044513d (patch)
tree14d2353e1dd594e9b695c250e3955c1da1eaf102 /kernel/context_tracking.c
parentsched: Consolidate open coded preemptible() checks (diff)
downloadlinux-2d854e5738cded368a0759f85b1197f5c044513d.tar.xz
linux-2d854e5738cded368a0759f85b1197f5c044513d.zip
context_tracing: Fix guest accounting with native vtime
1) If context tracking is enabled with native vtime accounting (which combo is useless except for dev testing), we call vtime_guest_enter() and vtime_guest_exit() on host <-> guest switches. But those are stubs in this configurations. As a result, cputime is not correctly flushed on kvm context switches. 2) If context tracking runs but is disabled on some CPUs, those CPUs end up calling __guest_enter/__guest_exit which in turn call vtime_account_system(). We don't want to call this because we run in tick based accounting for these CPUs. Refactor the guest_enter/guest_exit code such that all combinations finally work. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Kevin Hilman <khilman@linaro.org>
Diffstat (limited to '')
-rw-r--r--kernel/context_tracking.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 942835c12ae5..1f47119c5b09 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -141,12 +141,13 @@ void user_exit(void)
local_irq_restore(flags);
}
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
void guest_enter(void)
{
if (vtime_accounting_enabled())
vtime_guest_enter(current);
else
- __guest_enter();
+ current->flags |= PF_VCPU;
}
EXPORT_SYMBOL_GPL(guest_enter);
@@ -155,9 +156,10 @@ void guest_exit(void)
if (vtime_accounting_enabled())
vtime_guest_exit(current);
else
- __guest_exit();
+ current->flags &= ~PF_VCPU;
}
EXPORT_SYMBOL_GPL(guest_exit);
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
/**