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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-19 18:19:48 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-19 18:19:48 -0800 |
commit | d652e1eb8e7b739fccbfb503a3da3e9f640fbf3d (patch) | |
tree | 55ab77bad0cbb045eac0b84b80d63f88f1ae09e6 /kernel/context_tracking.c | |
parent | 8f55cea410dbc56114bb71a3742032070c8108d0 (diff) | |
parent | 77852fea6e2442a0e654a9292060489895de18c7 (diff) |
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.c | 43 |
1 files changed, 25 insertions, 18 deletions
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index d566aba7e80..65349f07b87 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 |