Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched

* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched: (140 commits)
  sched: sync wakeups preempt too
  sched: affine sync wakeups
  sched: guest CPU accounting: maintain guest state in KVM
  sched: guest CPU accounting: maintain stats in account_system_time()
  sched: guest CPU accounting: add guest-CPU /proc/<pid>/stat fields
  sched: guest CPU accounting: add guest-CPU /proc/stat field
  sched: domain sysctl fixes: add terminator comment
  sched: domain sysctl fixes: do not crash on allocation failure
  sched: domain sysctl fixes: unregister the sysctl table before domains
  sched: domain sysctl fixes: use for_each_online_cpu()
  sched: domain sysctl fixes: use kcalloc()
  Make scheduler debug file operations const
  sched: enable wake-idle on CONFIG_SCHED_MC=y
  sched: reintroduce topology.h tunings
  sched: allow the immediate migration of cache-cold tasks
  sched: debug, improve migration statistics
  sched: debug: increase width of debug line
  sched: activate task_hot() only on fair-scheduled tasks
  sched: reintroduce cache-hot affinity
  sched: speed up context-switches a bit
  ...

25 files changed, 1872 insertions, 1288 deletions

diff --git a/Documentation/sched-design-CFS.txt b/Documentation/sched-design-CFS.txt
index 84901e7c0508..88bcb8767335 100644
--- a/Documentation/sched-design-CFS.txt
+++ b/Documentation/sched-design-CFS.txt
@@ -117,3 +117,70 @@ Some implementation details:
    iterators of the scheduling modules are used. The balancing code got
    quite a bit simpler as a result.
 
+
+Group scheduler extension to CFS
+================================
+
+Normally the scheduler operates on individual tasks and strives to provide
+fair CPU time to each task. Sometimes, it may be desirable to group tasks
+and provide fair CPU time to each such task group. For example, it may
+be desirable to first provide fair CPU time to each user on the system
+and then to each task belonging to a user.
+
+CONFIG_FAIR_GROUP_SCHED strives to achieve exactly that. It lets
+SCHED_NORMAL/BATCH tasks be be grouped and divides CPU time fairly among such
+groups. At present, there are two (mutually exclusive) mechanisms to group
+tasks for CPU bandwidth control purpose:
+
+        - Based on user id (CONFIG_FAIR_USER_SCHED)
+                In this option, tasks are grouped according to their user id.
+        - Based on "cgroup" pseudo filesystem (CONFIG_FAIR_CGROUP_SCHED)
+                This options lets the administrator create arbitrary groups
+                of tasks, using the "cgroup" pseudo filesystem. See
+                Documentation/cgroups.txt for more information about this
+                filesystem.
+
+Only one of these options to group tasks can be chosen and not both.
+
+Group scheduler tunables:
+
+When CONFIG_FAIR_USER_SCHED is defined, a directory is created in sysfs for
+each new user and a "cpu_share" file is added in that directory.
+
+        # cd /sys/kernel/uids
+        # cat 512/cpu_share             # Display user 512's CPU share
+        1024
+        # echo 2048 > 512/cpu_share     # Modify user 512's CPU share
+        # cat 512/cpu_share             # Display user 512's CPU share
+        2048
+        #
+
+CPU bandwidth between two users are divided in the ratio of their CPU shares.
+For ex: if you would like user "root" to get twice the bandwidth of user
+"guest", then set the cpu_share for both the users such that "root"'s
+cpu_share is twice "guest"'s cpu_share
+
+
+When CONFIG_FAIR_CGROUP_SCHED is defined, a "cpu.shares" file is created
+for each group created using the pseudo filesystem. See example steps
+below to create task groups and modify their CPU share using the "cgroups"
+pseudo filesystem
+
+        # mkdir /dev/cpuctl
+        # mount -t cgroup -ocpu none /dev/cpuctl
+        # cd /dev/cpuctl
+
+        # mkdir multimedia      # create "multimedia" group of tasks
+        # mkdir browser         # create "browser" group of tasks
+
+        # #Configure the multimedia group to receive twice the CPU bandwidth
+        # #that of browser group
+
+        # echo 2048 > multimedia/cpu.shares
+        # echo 1024 > browser/cpu.shares
+
+        # firefox &     # Launch firefox and move it to "browser" group
+        # echo <firefox_pid> > browser/tasks
+
+        # #Launch gmplayer (or your favourite movie player)
+        # echo <movie_player_pid> > multimedia/tasks
diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index f1486f8a3e6d..bf9aafad4978 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -214,6 +214,17 @@ config X86_ES7000
 
 endchoice
 
+config SCHED_NO_NO_OMIT_FRAME_POINTER
+        bool "Single-depth WCHAN output"
+        default y
+        help
+          Calculate simpler /proc/<PID>/wchan values. If this option
+          is disabled then wchan values will recurse back to the
+          caller function. This provides more accurate wchan values,
+          at the expense of slightly more scheduling overhead.
+
+          If in doubt, say "Y".
+
 config PARAVIRT
         bool "Paravirtualization support (EXPERIMENTAL)"
         depends on EXPERIMENTAL
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index ad0813843adc..3b0bc4bda5f2 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -624,6 +624,16 @@ void kvm_mmu_unload(struct kvm_vcpu *vcpu);
 
 int kvm_hypercall(struct kvm_vcpu *vcpu, struct kvm_run *run);
 
+static inline void kvm_guest_enter(void)
+{
+        current->flags |= PF_VCPU;
+}
+
+static inline void kvm_guest_exit(void)
+{
+        current->flags &= ~PF_VCPU;
+}
+
 static inline int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
                                      u32 error_code)
 {
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 353e58527d15..af2d288c881d 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -2046,6 +2046,7 @@ again:
                 kvm_x86_ops->inject_pending_vectors(vcpu, kvm_run);
 
         vcpu->guest_mode = 1;
+        kvm_guest_enter();
 
         if (vcpu->requests)
                 if (test_and_clear_bit(KVM_TLB_FLUSH, &vcpu->requests))
@@ -2053,6 +2054,7 @@ again:
 
         kvm_x86_ops->run(vcpu, kvm_run);
 
+        kvm_guest_exit();
         vcpu->guest_mode = 0;
         local_irq_enable();
 
diff --git a/fs/pipe.c b/fs/pipe.c
index 6b3d91a691bf..e66ec48e95d8 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -45,8 +45,7 @@ void pipe_wait(struct pipe_inode_info *pipe)
          * Pipes are system-local resources, so sleeping on them
          * is considered a noninteractive wait:
          */
-        prepare_to_wait(&pipe->wait, &wait,
-                        TASK_INTERRUPTIBLE | TASK_NONINTERACTIVE);
+        prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE);
         if (pipe->inode)
                 mutex_unlock(&pipe->inode->i_mutex);
         schedule();