# Copyright (C) 2006-2013 OpenWrt.org # # This is free software, licensed under the GNU General Public License v2. # See /LICENSE for more information. # config KERNEL_DEBUG_FS bool "Compile the kernel with Debug FileSystem enabled" default y help debugfs is a virtual file system that kernel developers use to put debugging files into. Enable this option to be able to read and write to these files. config KERNEL_PERF_EVENTS bool default n config KERNEL_PROFILING bool "Compile the kernel with profiling enabled" default n select KERNEL_PERF_EVENTS help Enable the extended profiling support mechanisms used by profilers such as OProfile. config KERNEL_KALLSYMS bool "Compile the kernel with symbol table information" default y help This will give you more information in stack traces from kernel oopses config KERNEL_FTRACE bool "Compile the kernel with tracing support" default n config KERNEL_FTRACE_SYSCALLS bool "Trace system calls" depends on KERNEL_FTRACE default n config KERNEL_ENABLE_DEFAULT_TRACERS bool "Trace process context switches and events" depends on KERNEL_FTRACE default n config KERNEL_DEBUG_KERNEL bool default n config KERNEL_DEBUG_INFO bool "Compile the kernel with debug information" default y select KERNEL_DEBUG_KERNEL help This will compile your kernel and modules with debug information. config KERNEL_DEBUG_LL_UART_NONE bool default n depends on arm config KERNEL_DEBUG_LL bool default n depends on arm select KERNEL_DEBUG_LL_UART_NONE help ARM low level debugging config KERNEL_DYNAMIC_DEBUG bool "Compile the kernel with dynamic printk" select KERNEL_DEBUG_FS default n help Compiles debug level messages into the kernel, which would not otherwise be available at runtime. These messages can then be enabled/disabled based on various levels of scope - per source file, function, module, format string, and line number. This mechanism implicitly compiles in all pr_debug() and dev_dbg() calls, which enlarges the kernel text size by about 2%. config KERNEL_EARLY_PRINTK bool "Compile the kernel with early printk" default n depends on arm select KERNEL_DEBUG_KERNEL select KERNEL_DEBUG_LL if arm help Compile the kernel with early printk support. This is only useful for debugging purposes to send messages over the serial console in early boot. Enable this to debug early boot problems. config KERNEL_AIO bool "Compile the kernel with asynchronous IO support" default n config KERNEL_DIRECT_IO bool "Compile the kernel with direct IO support" default n config KERNEL_MAGIC_SYSRQ bool "Compile the kernel with SysRq support" default y config KERNEL_COREDUMP bool config KERNEL_ELF_CORE bool "Enable process core dump support" select KERNEL_COREDUMP default y config KERNEL_PROVE_LOCKING bool "Enable kernel lock checking" select KERNEL_DEBUG_KERNEL default n config KERNEL_PRINTK_TIME bool "Enable printk timestamps" default y config KERNEL_RELAY bool config KERNEL_KEXEC bool "Enable kexec support" config USE_RFKILL bool "Enable rfkill support" default RFKILL_SUPPORT # # CGROUP support symbols # config KERNEL_CGROUPS bool "Enable kernel cgroups" default n if KERNEL_CGROUPS config KERNEL_CGROUP_DEBUG bool "Example debug cgroup subsystem" default n help This option enables a simple cgroup subsystem that exports useful debugging information about the cgroups framework. config KERNEL_FREEZER bool default y if KERNEL_CGROUP_FREEZER config KERNEL_CGROUP_FREEZER bool "Freezer cgroup subsystem" default n help Provides a way to freeze and unfreeze all tasks in a cgroup. config KERNEL_CGROUP_DEVICE bool "Device controller for cgroups" default y help Provides a cgroup implementing whitelists for devices which a process in the cgroup can mknod or open. config KERNEL_CPUSETS bool "Cpuset support" default n help This option will let you create and manage CPUSETs which allow dynamically partitioning a system into sets of CPUs and Memory Nodes and assigning tasks to run only within those sets. This is primarily useful on large SMP or NUMA systems. config KERNEL_PROC_PID_CPUSET bool "Include legacy /proc/<pid>/cpuset file" default n depends on KERNEL_CPUSETS config KERNEL_CGROUP_CPUACCT bool "Simple CPU accounting cgroup subsystem" default n help Provides a simple Resource Controller for monitoring the total CPU consumed by the tasks in a cgroup. config KERNEL_RESOURCE_COUNTERS bool "Resource counters" default n help This option enables controller independent resource accounting infrastructure that works with cgroups. config KERNEL_MM_OWNER bool default y if KERNEL_MEMCG config KERNEL_MEMCG bool "Memory Resource Controller for Control Groups" default n depends on KERNEL_RESOURCE_COUNTERS help Provides a memory resource controller that manages both anonymous memory and page cache. (See Documentation/cgroups/memory.txt) Note that setting this option increases fixed memory overhead associated with each page of memory in the system. By this, 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory usage tracking struct at boot. Total amount of this is printed out at boot. Only enable when you're ok with these trade offs and really sure you need the memory resource controller. Even when you enable this, you can set "cgroup_disable=memory" at your boot option to disable memory resource controller and you can avoid overheads. (and lose benefits of memory resource controller) This config option also selects MM_OWNER config option, which could in turn add some fork/exit overhead. config KERNEL_MEMCG_SWAP bool "Memory Resource Controller Swap Extension" default n depends on KERNEL_MEMCG help Add swap management feature to memory resource controller. When you enable this, you can limit mem+swap usage per cgroup. In other words, when you disable this, memory resource controller has no cares to usage of swap...a process can exhaust all of the swap. This extension is useful when you want to avoid exhaustion swap but this itself adds more overheads and consumes memory for remembering information. Especially if you use 32bit system or small memory system, please be careful about enabling this. When memory resource controller is disabled by boot option, this will be automatically disabled and there will be no overhead from this. Even when you set this config=y, if boot option "swapaccount=0" is set, swap will not be accounted. Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page size is 4096bytes, 512k per 1Gbytes of swap. config KERNEL_MEMCG_SWAP_ENABLED bool "Memory Resource Controller Swap Extension enabled by default" default n depends on KERNEL_MEMCG_SWAP help Memory Resource Controller Swap Extension comes with its price in a bigger memory consumption. General purpose distribution kernels which want to enable the feature but keep it disabled by default and let the user enable it by swapaccount boot command line parameter should have this option unselected. For those who want to have the feature enabled by default should select this option (if, for some reason, they need to disable it then swapaccount=0 does the trick). config KERNEL_MEMCG_KMEM bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)" default n depends on KERNEL_MEMCG help The Kernel Memory extension for Memory Resource Controller can limit the amount of memory used by kernel objects in the system. Those are fundamentally different from the entities handled by the standard Memory Controller, which are page-based, and can be swapped. Users of the kmem extension can use it to guarantee that no group of processes will ever exhaust kernel resources alone. config KERNEL_PERF_EVENTS bool default y if KERNEL_CGROUP_PERF config KERNEL_CGROUP_PERF bool "Enable perf_event per-cpu per-container group (cgroup) monitoring" default n help This option extends the per-cpu mode to restrict monitoring to threads which belong to the cgroup specified and run on the designated cpu. menuconfig KERNEL_CGROUP_SCHED bool "Group CPU scheduler" default n help This feature lets CPU scheduler recognize task groups and control CPU bandwidth allocation to such task groups. It uses cgroups to group tasks. if KERNEL_CGROUP_SCHED config KERNEL_FAIR_GROUP_SCHED bool "Group scheduling for SCHED_OTHER" default n config KERNEL_CFS_BANDWIDTH bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED" default n depends on KERNEL_FAIR_GROUP_SCHED help This option allows users to define CPU bandwidth rates (limits) for tasks running within the fair group scheduler. Groups with no limit set are considered to be unconstrained and will run with no restriction. See tip/Documentation/scheduler/sched-bwc.txt for more information. config KERNEL_RT_GROUP_SCHED bool "Group scheduling for SCHED_RR/FIFO" default n help This feature lets you explicitly allocate real CPU bandwidth to task groups. If enabled, it will also make it impossible to schedule realtime tasks for non-root users until you allocate realtime bandwidth for them. endif config KERNEL_BLK_CGROUP bool "Block IO controller" default y help Generic block IO controller cgroup interface. This is the common cgroup interface which should be used by various IO controlling policies. Currently, CFQ IO scheduler uses it to recognize task groups and control disk bandwidth allocation (proportional time slice allocation) to such task groups. It is also used by bio throttling logic in block layer to implement upper limit in IO rates on a device. This option only enables generic Block IO controller infrastructure. One needs to also enable actual IO controlling logic/policy. For enabling proportional weight division of disk bandwidth in CFQ, set CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set CONFIG_BLK_DEV_THROTTLING=y. config KERNEL_DEBUG_BLK_CGROUP bool "Enable Block IO controller debugging" default n depends on KERNEL_BLK_CGROUP help Enable some debugging help. Currently it exports additional stat files in a cgroup which can be useful for debugging. config KERNEL_NET_CLS_CGROUP bool "Control Group Classifier" default y config KERNEL_NETPRIO_CGROUP bool "Network priority cgroup" default y endif # # Namespace support symbols # config KERNEL_NAMESPACES bool "Enable kernel namespaces" default n if KERNEL_NAMESPACES config KERNEL_UTS_NS bool "UTS namespace" default y help In this namespace tasks see different info provided with the uname() system call config KERNEL_IPC_NS bool "IPC namespace" default y help In this namespace tasks work with IPC ids which correspond to different IPC objects in different namespaces. config KERNEL_USER_NS bool "User namespace (EXPERIMENTAL)" default y help This allows containers, i.e. vservers, to use user namespaces to provide different user info for different servers. config KERNEL_PID_NS bool "PID Namespaces" default y help Support process id namespaces. This allows having multiple processes with the same pid as long as they are in different pid namespaces. This is a building block of containers. config KERNEL_NET_NS bool "Network namespace" default y help Allow user space to create what appear to be multiple instances of the network stack. endif # # LXC related symbols # config KERNEL_LXC_MISC bool "Enable miscellaneous LXC related options" default n if KERNEL_LXC_MISC config KERNEL_DEVPTS_MULTIPLE_INSTANCES bool "Support multiple instances of devpts" default y help Enable support for multiple instances of devpts filesystem. If you want to have isolated PTY namespaces (eg: in containers), say Y here. Otherwise, say N. If enabled, each mount of devpts filesystem with the '-o newinstance' option will create an independent PTY namespace. config KERNEL_POSIX_MQUEUE bool "POSIX Message Queues" default n help POSIX variant of message queues is a part of IPC. In POSIX message queues every message has a priority which decides about succession of receiving it by a process. If you want to compile and run programs written e.g. for Solaris with use of its POSIX message queues (functions mq_*) say Y here. POSIX message queues are visible as a filesystem called 'mqueue' and can be mounted somewhere if you want to do filesystem operations on message queues. endif