userfaultfd: mcopy_atomic|mfill_zeropage: UFFDIO_COPY|UFFDIO_ZEROPAGE preparation

[mirror_ubuntu-artful-kernel.git] / init / Kconfig

diff --git a/init/Kconfig b/init/Kconfig
index af09b4fb43d291856708eb78197adb74dd1b4f48..161acd8bc56fc5cc5bcf0ecd830e9ffcfa574873 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -538,15 +538,6 @@ config RCU_STALL_COMMON
 config CONTEXT_TRACKING
        bool
 
-config RCU_USER_QS
-       bool
-       help
-         This option sets hooks on kernel / userspace boundaries and
-         puts RCU in extended quiescent state when the CPU runs in
-         userspace. It means that when a CPU runs in userspace, it is
-         excluded from the global RCU state machine and thus doesn't
-         try to keep the timer tick on for RCU.
-
 config CONTEXT_TRACKING_FORCE
        bool "Force context tracking"
        depends on CONTEXT_TRACKING
@@ -707,6 +698,7 @@ config RCU_BOOST_DELAY
 config RCU_NOCB_CPU
        bool "Offload RCU callback processing from boot-selected CPUs"
        depends on TREE_RCU || PREEMPT_RCU
+       depends on RCU_EXPERT || NO_HZ_FULL
        default n
        help
          Use this option to reduce OS jitter for aggressive HPC or
@@ -955,6 +947,22 @@ config CGROUP_FREEZER
          Provides a way to freeze and unfreeze all tasks in a
          cgroup.
 
+config CGROUP_PIDS
+       bool "PIDs cgroup subsystem"
+       help
+         Provides enforcement of process number limits in the scope of a
+         cgroup. Any attempt to fork more processes than is allowed in the
+         cgroup will fail. PIDs are fundamentally a global resource because it
+         is fairly trivial to reach PID exhaustion before you reach even a
+         conservative kmemcg limit. As a result, it is possible to grind a
+         system to halt without being limited by other cgroup policies. The
+         PIDs cgroup subsystem is designed to stop this from happening.
+
+         It should be noted that organisational operations (such as attaching
+         to a cgroup hierarchy will *not* be blocked by the PIDs subsystem),
+         since the PIDs limit only affects a process's ability to fork, not to
+         attach to a cgroup.
+
 config CGROUP_DEVICE
        bool "Device controller for cgroups"
        help
@@ -1568,6 +1576,17 @@ config ADVISE_SYSCALLS
          applications use these syscalls, you can disable this option to save
          space.
 
+config USERFAULTFD
+       bool "Enable userfaultfd() system call"
+       select ANON_INODES
+       default y
+       depends on MMU
+       help
+         Enable the userfaultfd() system call that allows to intercept and
+         handle page faults in userland.
+
+         If unsure, say Y.
+
 config PCI_QUIRKS
        default y
        bool "Enable PCI quirk workarounds" if EXPERT