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author | Frederic Weisbecker <fweisbec@gmail.com> | 2012-12-16 20:00:34 +0100 |
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committer | Frederic Weisbecker <fweisbec@gmail.com> | 2013-01-27 20:35:47 +0100 |
commit | 6a61671bb2f3a1bd12cd17b8fca811a624782632 (patch) | |
tree | 0afc2915fb7e517472710a49a524510322dd5baa /include/linux/kvm_host.h | |
parent | c11f11fcbdb5be790c565aed46411486a7586afc (diff) | |
download | linux-stable-6a61671bb2f3a1bd12cd17b8fca811a624782632.tar.gz linux-stable-6a61671bb2f3a1bd12cd17b8fca811a624782632.tar.bz2 linux-stable-6a61671bb2f3a1bd12cd17b8fca811a624782632.zip |
cputime: Safely read cputime of full dynticks CPUs
While remotely reading the cputime of a task running in a
full dynticks CPU, the values stored in utime/stime fields
of struct task_struct may be stale. Its values may be those
of the last kernel <-> user transition time snapshot and
we need to add the tickless time spent since this snapshot.
To fix this, flush the cputime of the dynticks CPUs on
kernel <-> user transition and record the time / context
where we did this. Then on top of this snapshot and the current
time, perform the fixup on the reader side from task_times()
accessors.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
[fixed kvm module related build errors]
Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
Diffstat (limited to 'include/linux/kvm_host.h')
-rw-r--r-- | include/linux/kvm_host.h | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 4fe2396401da..b7996a768eb2 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -741,7 +741,7 @@ static inline int kvm_deassign_device(struct kvm *kvm, } #endif /* CONFIG_IOMMU_API */ -static inline void guest_enter(void) +static inline void __guest_enter(void) { /* * This is running in ioctl context so we can avoid @@ -751,7 +751,7 @@ static inline void guest_enter(void) current->flags |= PF_VCPU; } -static inline void guest_exit(void) +static inline void __guest_exit(void) { /* * This is running in ioctl context so we can avoid @@ -761,6 +761,22 @@ static inline void guest_exit(void) current->flags &= ~PF_VCPU; } +#ifdef CONFIG_CONTEXT_TRACKING +extern void guest_enter(void); +extern void guest_exit(void); + +#else /* !CONFIG_CONTEXT_TRACKING */ +static inline void guest_enter(void) +{ + __guest_enter(); +} + +static inline void guest_exit(void) +{ + __guest_exit(); +} +#endif /* !CONFIG_CONTEXT_TRACKING */ + static inline void kvm_guest_enter(void) { unsigned long flags; |