Merge tag 'full-dynticks-cputime-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/core

Pull 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:

 "This implements the cputime accounting on full dynticks CPUs.

  Typical cputime stats infrastructure relies on the timer tick and
  its periodic polling on the CPU to account the amount of time
  spent by the CPUs and the tasks per high level domains such as
  userspace, kernelspace, guest, ...

  Now we are preparing to implement full dynticks capability on
  Linux for Real Time and HPC users who want full CPU isolation.
  This feature requires a cputime accounting that doesn't depend
  on the timer tick.

  To implement it, this new cputime infrastructure plugs into
  kernel/user/guest boundaries to take snapshots of cputime and
  flush these to the stats when needed. This performs pretty
  much like CONFIG_VIRT_CPU_ACCOUNTING except that context location
  and cputime snaphots are synchronized between write and read
  side such that the latter can safely retrieve the pending tickless
  cputime of a task and add it to its latest cputime snapshot to
  return the correct result to the user."

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

7 files changed, 21 insertions, 20 deletions

diff --git a/arch/ia64/kernel/asm-offsets.c b/arch/ia64/kernel/asm-offsets.c
index a48bd9a9927b..46c9e3007315 100644
--- a/arch/ia64/kernel/asm-offsets.c
+++ b/arch/ia64/kernel/asm-offsets.c
@@ -41,7 +41,7 @@ void foo(void)
         DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
         DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
         DEFINE(TI_PRE_COUNT, offsetof(struct thread_info, preempt_count));
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
         DEFINE(TI_AC_STAMP, offsetof(struct thread_info, ac_stamp));
         DEFINE(TI_AC_LEAVE, offsetof(struct thread_info, ac_leave));
         DEFINE(TI_AC_STIME, offsetof(struct thread_info, ac_stime));
diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S
index 6bfd8429ee0f..7a53530f22c2 100644
--- a/arch/ia64/kernel/entry.S
+++ b/arch/ia64/kernel/entry.S
@@ -724,7 +724,7 @@ GLOBAL_ENTRY(__paravirt_leave_syscall)
 #endif
 .global __paravirt_work_processed_syscall;
 __paravirt_work_processed_syscall:
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
         adds r2=PT(LOADRS)+16,r12
         MOV_FROM_ITC(pUStk, p9, r22, r19)       // fetch time at leave
         adds r18=TI_FLAGS+IA64_TASK_SIZE,r13
@@ -762,7 +762,7 @@ __paravirt_work_processed_syscall:
 
         ld8 r29=[r2],16         // M0|1 load cr.ipsr
         ld8 r28=[r3],16         // M0|1 load cr.iip
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 (pUStk) add r14=TI_AC_LEAVE+IA64_TASK_SIZE,r13
         ;;
         ld8 r30=[r2],16         // M0|1 load cr.ifs
@@ -793,7 +793,7 @@ __paravirt_work_processed_syscall:
         ld8.fill r1=[r3],16                     // M0|1 load r1
 (pUStk) mov r17=1                               // A
         ;;
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 (pUStk) st1 [r15]=r17                           // M2|3
 #else
 (pUStk) st1 [r14]=r17                           // M2|3
@@ -813,7 +813,7 @@ __paravirt_work_processed_syscall:
         shr.u r18=r19,16                // I0|1 get byte size of existing "dirty" partition
         COVER                           // B    add current frame into dirty partition & set cr.ifs
         ;;
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
         mov r19=ar.bsp                  // M2   get new backing store pointer
         st8 [r14]=r22                   // M    save time at leave
         mov f10=f0                      // F    clear f10
@@ -948,7 +948,7 @@ GLOBAL_ENTRY(__paravirt_leave_kernel)
         adds r16=PT(CR_IPSR)+16,r12
         adds r17=PT(CR_IIP)+16,r12
 
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
         .pred.rel.mutex pUStk,pKStk
         MOV_FROM_PSR(pKStk, r22, r29)   // M2 read PSR now that interrupts are disabled
         MOV_FROM_ITC(pUStk, p9, r22, r29)       // M  fetch time at leave
@@ -981,7 +981,7 @@ GLOBAL_ENTRY(__paravirt_leave_kernel)
         ;;
         ld8.fill r12=[r16],16
         ld8.fill r13=[r17],16
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 (pUStk) adds r3=TI_AC_LEAVE+IA64_TASK_SIZE,r18
 #else
 (pUStk) adds r18=IA64_TASK_THREAD_ON_USTACK_OFFSET,r18
@@ -989,7 +989,7 @@ GLOBAL_ENTRY(__paravirt_leave_kernel)
         ;;
         ld8 r20=[r16],16        // ar.fpsr
         ld8.fill r15=[r17],16
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 (pUStk) adds r18=IA64_TASK_THREAD_ON_USTACK_OFFSET,r18  // deferred
 #endif
         ;;
@@ -997,7 +997,7 @@ GLOBAL_ENTRY(__paravirt_leave_kernel)
         ld8.fill r2=[r17]
 (pUStk) mov r17=1
         ;;
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
         //  mmi_ :  ld8 st1 shr;;         mmi_ : st8 st1 shr;;
         //  mib  :  mov add br        ->  mib  : ld8 add br
         //  bbb_ :  br  nop cover;;       mbb_ : mov br  cover;;
diff --git a/arch/ia64/kernel/fsys.S b/arch/ia64/kernel/fsys.S
index e662f178b990..c4cd45d97749 100644
--- a/arch/ia64/kernel/fsys.S
+++ b/arch/ia64/kernel/fsys.S
@@ -529,7 +529,7 @@ GLOBAL_ENTRY(paravirt_fsys_bubble_down)
         nop.i 0
         ;;
         mov ar.rsc=0                            // M2   set enforced lazy mode, pl 0, LE, loadrs=0
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
         MOV_FROM_ITC(p0, p6, r30, r23)          // M    get cycle for accounting
 #else
         nop.m 0
@@ -555,7 +555,7 @@ GLOBAL_ENTRY(paravirt_fsys_bubble_down)
         cmp.ne pKStk,pUStk=r0,r0                // A    set pKStk <- 0, pUStk <- 1
         br.call.sptk.many b7=ia64_syscall_setup // B
         ;;
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
         // mov.m r30=ar.itc is called in advance
         add r16=TI_AC_STAMP+IA64_TASK_SIZE,r2
         add r17=TI_AC_LEAVE+IA64_TASK_SIZE,r2
diff --git a/arch/ia64/kernel/head.S b/arch/ia64/kernel/head.S
index 4738ff7bd66a..9be4e497f3d3 100644
--- a/arch/ia64/kernel/head.S
+++ b/arch/ia64/kernel/head.S
@@ -1073,7 +1073,7 @@ END(ia64_native_sched_clock)
 sched_clock = ia64_native_sched_clock
 #endif
 
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 GLOBAL_ENTRY(cycle_to_cputime)
         alloc r16=ar.pfs,1,0,0,0
         addl r8=THIS_CPU(ia64_cpu_info) + IA64_CPUINFO_NSEC_PER_CYC_OFFSET,r0
@@ -1091,7 +1091,7 @@ GLOBAL_ENTRY(cycle_to_cputime)
         shrp r8=r9,r8,IA64_NSEC_PER_CYC_SHIFT
         br.ret.sptk.many rp
 END(cycle_to_cputime)
-#endif /* CONFIG_VIRT_CPU_ACCOUNTING */
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
 
 #ifdef CONFIG_IA64_BRL_EMU
 
diff --git a/arch/ia64/kernel/ivt.S b/arch/ia64/kernel/ivt.S
index fa25689fc453..689ffcaa284e 100644
--- a/arch/ia64/kernel/ivt.S
+++ b/arch/ia64/kernel/ivt.S
@@ -784,7 +784,7 @@ ENTRY(break_fault)
 
 (p8)    adds r28=16,r28                         // A    switch cr.iip to next bundle
 (p9)    adds r8=1,r8                            // A    increment ei to next slot
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
         ;;
         mov b6=r30                              // I0   setup syscall handler branch reg early
 #else
@@ -801,7 +801,7 @@ ENTRY(break_fault)
         //
 ///////////////////////////////////////////////////////////////////////
         st1 [r16]=r0                            // M2|3 clear current->thread.on_ustack flag
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
         MOV_FROM_ITC(p0, p14, r30, r18)         // M    get cycle for accounting
 #else
         mov b6=r30                              // I0   setup syscall handler branch reg early
@@ -817,7 +817,7 @@ ENTRY(break_fault)
         cmp.eq p14,p0=r9,r0                     // A    are syscalls being traced/audited?
         br.call.sptk.many b7=ia64_syscall_setup // B
 1:
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
         // mov.m r30=ar.itc is called in advance, and r13 is current
         add r16=TI_AC_STAMP+IA64_TASK_SIZE,r13  // A
         add r17=TI_AC_LEAVE+IA64_TASK_SIZE,r13  // A
@@ -1043,7 +1043,7 @@ END(ia64_syscall_setup)
         DBG_FAULT(16)
         FAULT(16)
 
-#if defined(CONFIG_VIRT_CPU_ACCOUNTING) && defined(__IA64_ASM_PARAVIRTUALIZED_NATIVE)
+#if defined(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) && defined(__IA64_ASM_PARAVIRTUALIZED_NATIVE)
         /*
          * There is no particular reason for this code to be here, other than
          * that there happens to be space here that would go unused otherwise.
diff --git a/arch/ia64/kernel/minstate.h b/arch/ia64/kernel/minstate.h
index d56753a11636..cc82a7d744c9 100644
--- a/arch/ia64/kernel/minstate.h
+++ b/arch/ia64/kernel/minstate.h
@@ -4,7 +4,7 @@
 #include "entry.h"
 #include "paravirt_inst.h"
 
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 /* read ar.itc in advance, and use it before leaving bank 0 */
 #define ACCOUNT_GET_STAMP                               \
 (pUStk) mov.m r20=ar.itc;
diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 88a794536bc0..fbaac1afb844 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -77,7 +77,7 @@ static struct clocksource clocksource_itc = {
 };
 static struct clocksource *itc_clocksource;
 
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 
 #include <linux/kernel_stat.h>
 
@@ -136,13 +136,14 @@ void vtime_account_system(struct task_struct *tsk)
 
         account_system_time(tsk, 0, delta, delta);
 }
+EXPORT_SYMBOL_GPL(vtime_account_system);
 
 void vtime_account_idle(struct task_struct *tsk)
 {
         account_idle_time(vtime_delta(tsk));
 }
 
-#endif /* CONFIG_VIRT_CPU_ACCOUNTING */
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
 
 static irqreturn_t
 timer_interrupt (int irq, void *dev_id)