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author | Frederic Weisbecker <fweisbec@gmail.com> | 2013-07-12 19:02:30 +0200 |
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committer | Frederic Weisbecker <fweisbec@gmail.com> | 2013-08-13 00:40:44 +0200 |
commit | 2d854e5738cded368a0759f85b1197f5c044513d (patch) | |
tree | 14d2353e1dd594e9b695c250e3955c1da1eaf102 /include/linux/context_tracking.h | |
parent | fbb00b568bc93073452d2a0f9f06e7c33d16eece (diff) | |
download | linux-stable-2d854e5738cded368a0759f85b1197f5c044513d.tar.gz linux-stable-2d854e5738cded368a0759f85b1197f5c044513d.tar.bz2 linux-stable-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 'include/linux/context_tracking.h')
-rw-r--r-- | include/linux/context_tracking.h | 52 |
1 files changed, 22 insertions, 30 deletions
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h index fc09d7b0dacf..5984f2556d13 100644 --- a/include/linux/context_tracking.h +++ b/include/linux/context_tracking.h @@ -20,25 +20,6 @@ struct context_tracking { } state; }; -static inline void __guest_enter(void) -{ - /* - * This is running in ioctl context so we can avoid - * the call to vtime_account() with its unnecessary idle check. - */ - vtime_account_system(current); - current->flags |= PF_VCPU; -} - -static inline void __guest_exit(void) -{ - /* - * This is running in ioctl context so we can avoid - * the call to vtime_account() with its unnecessary idle check. - */ - vtime_account_system(current); - current->flags &= ~PF_VCPU; -} #ifdef CONFIG_CONTEXT_TRACKING DECLARE_PER_CPU(struct context_tracking, context_tracking); @@ -56,9 +37,6 @@ static inline bool context_tracking_active(void) extern void user_enter(void); extern void user_exit(void); -extern void guest_enter(void); -extern void guest_exit(void); - static inline enum ctx_state exception_enter(void) { enum ctx_state prev_ctx; @@ -81,21 +59,35 @@ extern void context_tracking_task_switch(struct task_struct *prev, static inline bool context_tracking_in_user(void) { return false; } static inline void user_enter(void) { } static inline void user_exit(void) { } +static inline enum ctx_state exception_enter(void) { return 0; } +static inline void exception_exit(enum ctx_state prev_ctx) { } +static inline void context_tracking_task_switch(struct task_struct *prev, + struct task_struct *next) { } +#endif /* !CONFIG_CONTEXT_TRACKING */ +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN +extern void guest_enter(void); +extern void guest_exit(void); +#else static inline void guest_enter(void) { - __guest_enter(); + /* + * This is running in ioctl context so we can avoid + * the call to vtime_account() with its unnecessary idle check. + */ + vtime_account_system(current); + current->flags |= PF_VCPU; } static inline void guest_exit(void) { - __guest_exit(); + /* + * This is running in ioctl context so we can avoid + * the call to vtime_account() with its unnecessary idle check. + */ + vtime_account_system(current); + current->flags &= ~PF_VCPU; } - -static inline enum ctx_state exception_enter(void) { return 0; } -static inline void exception_exit(enum ctx_state prev_ctx) { } -static inline void context_tracking_task_switch(struct task_struct *prev, - struct task_struct *next) { } -#endif /* !CONFIG_CONTEXT_TRACKING */ +#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */ #endif |