Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "The main changes in this cycle were:

   - another round of rq-clock handling debugging, robustization and
     fixes

   - PELT accounting improvements

   - CPU hotplug related ->cpus_allowed affinity handling fixes all
     around the tree

   - ... plus misc fixes, cleanups and updates"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits)
  sched/x86: Update reschedule warning text
  crypto: N2 - Replace racy task affinity logic
  cpufreq/sparc-us2e: Replace racy task affinity logic
  cpufreq/sparc-us3: Replace racy task affinity logic
  cpufreq/sh: Replace racy task affinity logic
  cpufreq/ia64: Replace racy task affinity logic
  ACPI/processor: Replace racy task affinity logic
  ACPI/processor: Fix error handling in __acpi_processor_start()
  sparc/sysfs: Replace racy task affinity logic
  powerpc/smp: Replace open coded task affinity logic
  ia64/sn/hwperf: Replace racy task affinity logic
  ia64/salinfo: Replace racy task affinity logic
  workqueue: Provide work_on_cpu_safe()
  ia64/topology: Remove cpus_allowed manipulation
  sched/fair: Move the PELT constants into a generated header
  sched/fair: Increase PELT accuracy for small tasks
  sched/fair: Fix comments
  sched/Documentation: Add 'sched-pelt' tool
  sched/fair: Fix corner case in __accumulate_sum()
  sched/core: Remove 'task' parameter and rename tsk_restore_flags() to current_restore_flags()
  ...

3 files changed, 21 insertions, 33 deletions

diff --git a/arch/ia64/kernel/salinfo.c b/arch/ia64/kernel/salinfo.c
index d194d5c83d32..63dc9cdc95c5 100644
--- a/arch/ia64/kernel/salinfo.c
+++ b/arch/ia64/kernel/salinfo.c
@@ -179,14 +179,14 @@ struct salinfo_platform_oemdata_parms {
         const u8 *efi_guid;
         u8 **oemdata;
         u64 *oemdata_size;
-        int ret;
 };
 
-static void
+static long
 salinfo_platform_oemdata_cpu(void *context)
 {
         struct salinfo_platform_oemdata_parms *parms = context;
-        parms->ret = salinfo_platform_oemdata(parms->efi_guid, parms->oemdata, parms->oemdata_size);
+
+        return salinfo_platform_oemdata(parms->efi_guid, parms->oemdata, parms->oemdata_size);
 }
 
 static void
@@ -380,16 +380,7 @@ salinfo_log_release(struct inode *inode, struct file *file)
         return 0;
 }
 
-static void
-call_on_cpu(int cpu, void (*fn)(void *), void *arg)
-{
-        cpumask_t save_cpus_allowed = current->cpus_allowed;
-        set_cpus_allowed_ptr(current, cpumask_of(cpu));
-        (*fn)(arg);
-        set_cpus_allowed_ptr(current, &save_cpus_allowed);
-}
-
-static void
+static long
 salinfo_log_read_cpu(void *context)
 {
         struct salinfo_data *data = context;
@@ -399,6 +390,7 @@ salinfo_log_read_cpu(void *context)
         /* Clear corrected errors as they are read from SAL */
         if (rh->severity == sal_log_severity_corrected)
                 ia64_sal_clear_state_info(data->type);
+        return 0;
 }
 
 static void
@@ -430,7 +422,7 @@ retry:
         spin_unlock_irqrestore(&data_saved_lock, flags);
 
         if (!data->saved_num)
-                call_on_cpu(cpu, salinfo_log_read_cpu, data);
+                work_on_cpu_safe(cpu, salinfo_log_read_cpu, data);
         if (!data->log_size) {
                 data->state = STATE_NO_DATA;
                 cpumask_clear_cpu(cpu, &data->cpu_event);
@@ -459,11 +451,13 @@ salinfo_log_read(struct file *file, char __user *buffer, size_t count, loff_t *p
         return simple_read_from_buffer(buffer, count, ppos, buf, bufsize);
 }
 
-static void
+static long
 salinfo_log_clear_cpu(void *context)
 {
         struct salinfo_data *data = context;
+
         ia64_sal_clear_state_info(data->type);
+        return 0;
 }
 
 static int
@@ -486,7 +480,7 @@ salinfo_log_clear(struct salinfo_data *data, int cpu)
         rh = (sal_log_record_header_t *)(data->log_buffer);
         /* Corrected errors have already been cleared from SAL */
         if (rh->severity != sal_log_severity_corrected)
-                call_on_cpu(cpu, salinfo_log_clear_cpu, data);
+                work_on_cpu_safe(cpu, salinfo_log_clear_cpu, data);
         /* clearing a record may make a new record visible */
         salinfo_log_new_read(cpu, data);
         if (data->state == STATE_LOG_RECORD) {
@@ -531,9 +525,8 @@ salinfo_log_write(struct file *file, const char __user *buffer, size_t count, lo
                                 .oemdata = &data->oemdata,
                                 .oemdata_size = &data->oemdata_size
                         };
-                        call_on_cpu(cpu, salinfo_platform_oemdata_cpu, &parms);
-                        if (parms.ret)
-                                count = parms.ret;
+                        count = work_on_cpu_safe(cpu, salinfo_platform_oemdata_cpu,
+                                                 &parms);
                 } else
                         data->oemdata_size = 0;
         } else
diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c
index 1a68f012a6dc..d76529cbff20 100644
--- a/arch/ia64/kernel/topology.c
+++ b/arch/ia64/kernel/topology.c
@@ -355,18 +355,12 @@ static int cache_add_dev(unsigned int cpu)
         unsigned long i, j;
         struct cache_info *this_object;
         int retval = 0;
-        cpumask_t oldmask;
 
         if (all_cpu_cache_info[cpu].kobj.parent)
                 return 0;
 
-        oldmask = current->cpus_allowed;
-        retval = set_cpus_allowed_ptr(current, cpumask_of(cpu));
-        if (unlikely(retval))
-                return retval;
 
         retval = cpu_cache_sysfs_init(cpu);
-        set_cpus_allowed_ptr(current, &oldmask);
         if (unlikely(retval < 0))
                 return retval;
 
diff --git a/arch/ia64/sn/kernel/sn2/sn_hwperf.c b/arch/ia64/sn/kernel/sn2/sn_hwperf.c
index 52704f199dd6..55febd65911a 100644
--- a/arch/ia64/sn/kernel/sn2/sn_hwperf.c
+++ b/arch/ia64/sn/kernel/sn2/sn_hwperf.c
@@ -598,12 +598,17 @@ static void sn_hwperf_call_sal(void *info)
         op_info->ret = r;
 }
 
+static long sn_hwperf_call_sal_work(void *info)
+{
+        sn_hwperf_call_sal(info);
+        return 0;
+}
+
 static int sn_hwperf_op_cpu(struct sn_hwperf_op_info *op_info)
 {
         u32 cpu;
         u32 use_ipi;
         int r = 0;
-        cpumask_t save_allowed;
         
         cpu = (op_info->a->arg & SN_HWPERF_ARG_CPU_MASK) >> 32;
         use_ipi = op_info->a->arg & SN_HWPERF_ARG_USE_IPI_MASK;
@@ -629,13 +634,9 @@ static int sn_hwperf_op_cpu(struct sn_hwperf_op_info *op_info)
                         /* use an interprocessor interrupt to call SAL */
                         smp_call_function_single(cpu, sn_hwperf_call_sal,
                                 op_info, 1);
-                }
-                else {
-                        /* migrate the task before calling SAL */ 
-                        save_allowed = current->cpus_allowed;
-                        set_cpus_allowed_ptr(current, cpumask_of(cpu));
-                        sn_hwperf_call_sal(op_info);
-                        set_cpus_allowed_ptr(current, &save_allowed);
+                } else {
+                        /* Call on the target CPU */
+                        work_on_cpu_safe(cpu, sn_hwperf_call_sal_work, op_info);
                 }
         }
         r = op_info->ret;