diff options
| -rw-r--r-- | Documentation/cpusets.txt | 407 | ||||
| -rw-r--r-- | fs/proc/array.c | 2 | ||||
| -rw-r--r-- | fs/proc/base.c | 19 | ||||
| -rw-r--r-- | include/linux/cpuset.h | 64 | ||||
| -rw-r--r-- | include/linux/sched.h | 7 | ||||
| -rw-r--r-- | init/Kconfig | 10 | ||||
| -rw-r--r-- | init/main.c | 5 | ||||
| -rw-r--r-- | kernel/Makefile | 1 | ||||
| -rw-r--r-- | kernel/cpuset.c | 1534 | ||||
| -rw-r--r-- | kernel/exit.c | 2 | ||||
| -rw-r--r-- | kernel/fork.c | 3 | ||||
| -rw-r--r-- | kernel/sched.c | 6 | ||||
| -rw-r--r-- | mm/mempolicy.c | 13 | ||||
| -rw-r--r-- | mm/page_alloc.c | 16 | ||||
| -rw-r--r-- | mm/vmscan.c | 19 |
15 files changed, 2104 insertions, 4 deletions
diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt new file mode 100644 index 000000000000..488792243d15 --- /dev/null +++ b/Documentation/cpusets.txt @@ -0,0 +1,407 @@ + CPUSETS + ------- + +Copyright (C) 2004 BULL SA. +Written by Simon.Derr@bull.net + +Portions Copyright (c) 2004 Silicon Graphics, Inc. +Modified by Paul Jackson <pj@sgi.com> + +CONTENTS: +========= + +1. Cpusets + 1.1 What are cpusets ? + 1.2 Why are cpusets needed ? + 1.3 How are cpusets implemented ? + 1.4 How do I use cpusets ? +2. Usage Examples and Syntax + 2.1 Basic Usage + 2.2 Adding/removing cpus + 2.3 Setting flags + 2.4 Attaching processes +3. Questions +4. Contact + +1. Cpusets +========== + +1.1 What are cpusets ? +---------------------- + +Cpusets provide a mechanism for assigning a set of CPUs and Memory +Nodes to a set of tasks. + +Cpusets constrain the CPU and Memory placement of tasks to only +the resources within a tasks current cpuset. They form a nested +hierarchy visible in a virtual file system. These are the essential +hooks, beyond what is already present, required to manage dynamic +job placement on large systems. + +Each task has a pointer to a cpuset. Multiple tasks may reference +the same cpuset. Requests by a task, using the sched_setaffinity(2) +system call to include CPUs in its CPU affinity mask, and using the +mbind(2) and set_mempolicy(2) system calls to include Memory Nodes +in its memory policy, are both filtered through that tasks cpuset, +filtering out any CPUs or Memory Nodes not in that cpuset. The +scheduler will not schedule a task on a CPU that is not allowed in +its cpus_allowed vector, and the kernel page allocator will not +allocate a page on a node that is not allowed in the requesting tasks +mems_allowed vector. + +If a cpuset is cpu or mem exclusive, no other cpuset, other than a direct +ancestor or descendent, may share any of the same CPUs or Memory Nodes. + +User level code may create and destroy cpusets by name in the cpuset +virtual file system, manage the attributes and permissions of these +cpusets and which CPUs and Memory Nodes are assigned to each cpuset, +specify and query to which cpuset a task is assigned, and list the +task pids assigned to a cpuset. + + +1.2 Why are cpusets needed ? +---------------------------- + +The management of large computer systems, with many processors (CPUs), +complex memory cache hierarchies and multiple Memory Nodes having +non-uniform access times (NUMA) presents additional challenges for +the efficient scheduling and memory placement of processes. + +Frequently more modest sized systems can be operated with adequate +efficiency just by letting the operating system automatically share +the available CPU and Memory resources amongst the requesting tasks. + +But larger systems, which benefit more from careful processor and +memory placement to reduce memory access times and contention, +and which typically represent a larger investment for the customer, +can benefit from explictly placing jobs on properly sized subsets of +the system. + +This can be especially valuable on: + + * Web Servers running multiple instances of the same web application, + * Servers running different applications (for instance, a web server + and a database), or + * NUMA systems running large HPC applications with demanding + performance characteristics. + +These subsets, or "soft partitions" must be able to be dynamically +adjusted, as the job mix changes, without impacting other concurrently +executing jobs. + +The kernel cpuset patch provides the minimum essential kernel +mechanisms required to efficiently implement such subsets. It +leverages existing CPU and Memory Placement facilities in the Linux +kernel to avoid any additional impact on the critical scheduler or +memory allocator code. + + +1.3 How are cpusets implemented ? +--------------------------------- + +Cpusets provide a Linux kernel (2.6.7 and above) mechanism to constrain +which CPUs and Memory Nodes are used by a process or set of processes. + +The Linux kernel already has a pair of mechanisms to specify on which +CPUs a task may be scheduled (sched_setaffinity) and on which Memory +Nodes it may obtain memory (mbind, set_mempolicy). + +Cpusets extends these two mechanisms as follows: + + - Cpusets are sets of allowed CPUs and Memory Nodes, known to the + kernel. + - Each task in the system is attached to a cpuset, via a pointer + in the task structure to a reference counted cpuset structure. + - Calls to sched_setaffinity are filtered to just those CPUs + allowed in that tasks cpuset. + - Calls to mbind and set_mempolicy are filtered to just + those Memory Nodes allowed in that tasks cpuset. + - The root cpuset contains all the systems CPUs and Memory + Nodes. + - For any cpuset, one can define child cpusets containing a subset + of the parents CPU and Memory Node resources. + - The hierarchy of cpusets can be mounted at /dev/cpuset, for + browsing and manipulation from user space. + - A cpuset may be marked exclusive, which ensures that no other + cpuset (except direct ancestors and descendents) may contain + any overlapping CPUs or Memory Nodes. + - You can list all the tasks (by pid) attached to any cpuset. + +The implementation of cpusets requires a few, simple hooks +into the rest of the kernel, none in performance critical paths: + + - in main/init.c, to initialize the root cpuset at system boot. + - in fork and exit, to attach and detach a task from its cpuset. + - in sched_setaffinity, to mask the requested CPUs by what's + allowed in that tasks cpuset. + - in sched.c migrate_all_tasks(), to keep migrating tasks within + the CPUs allowed by their cpuset, if possible. + - in the mbind and set_mempolicy system calls, to mask the requested + Memory Nodes by what's allowed in that tasks cpuset. + - in page_alloc, to restrict memory to allowed nodes. + - in vmscan.c, to restrict page recovery to the current cpuset. + +In addition a new file system, of type "cpuset" may be mounted, +typically at /dev/cpuset, to enable browsing and modifying the cpusets +presently known to the kernel. No new system calls are added for +cpusets - all support for querying and modifying cpusets is via +this cpuset file system. + +Each task under /proc has an added file named 'cpuset', displaying +the cpuset name, as the path relative to the root of the cpuset file +system. + +The /proc/<pid>/status file for each task has two added lines, +displaying the tasks cpus_allowed (on which CPUs it may be scheduled) +and mems_allowed (on which Memory Nodes it may obtain memory), +in the format seen in the following example: + + Cpus_allowed: ffffffff,ffffffff,ffffffff,ffffffff + Mems_allowed: ffffffff,ffffffff + +Each cpuset is represented by a directory in the cpuset file system +containing the following files describing that cpuset: + + - cpus: list of CPUs in that cpuset + - mems: list of Memory Nodes in that cpuset + - cpu_exclusive flag: is cpu placement exclusive? + - mem_exclusive flag: is memory placement exclusive? + - tasks: list of tasks (by pid) attached to that cpuset + +New cpusets are created using the mkdir system call or shell +command. The properties of a cpuset, such as its flags, allowed +CPUs and Memory Nodes, and attached tasks, are modified by writing +to the appropriate file in that cpusets directory, as listed above. + +The named hierarchical structure of nested cpusets allows partitioning +a large system into nested, dynamically changeable, "soft-partitions". + +The attachment of each task, automatically inherited at fork by any +children of that task, to a cpuset allows organizing the work load +on a system into related sets of tasks such that each set is constrained +to using the CPUs and Memory Nodes of a particular cpuset. A task +may be re-attached to any other cpuset, if allowed by the permissions +on the necessary cpuset file system directories. + +Such management of a system "in the large" integrates smoothly with +the detailed placement done on individual tasks and memory regions +using the sched_setaffinity, mbind and set_mempolicy system calls. + +The following rules apply to each cpuset: + + - Its CPUs and Memory Nodes must be a subset of its parents. + - It can only be marked exclusive if its parent is. + - If its cpu or memory is exclusive, they may not overlap any sibling. + +These rules, and the natural hierarchy of cpusets, enable efficient +enforcement of the exclusive guarantee, without having to scan all +cpusets every time any of them change to ensure nothing overlaps a +exclusive cpuset. Also, the use of a Linux virtual file system (vfs) +to represent the cpuset hierarchy provides for a familiar permission +and name space for cpusets, with a minimum of additional kernel code. + +1.4 How do I use cpusets ? +-------------------------- + +In order to minimize the impact of cpusets on critical kernel +code, such as the scheduler, and due to the fact that the kernel +does not support one task updating the memory placement of another +task directly, the impact on a task of changing its cpuset CPU +or Memory Node placement, or of changing to which cpuset a task +is attached, is subtle. + +If a cpuset has its Memory Nodes modified, then for each task attached +to that cpuset, the next time that the kernel attempts to allocate +a page of memory for that task, the kernel will notice the change +in the tasks cpuset, and update its per-task memory placement to +remain within the new cpusets memory placement. If the task was using +mempolicy MPOL_BIND, and the nodes to which it was bound overlap with +its new cpuset, then the task will continue to use whatever subset +of MPOL_BIND nodes are still allowed in the new cpuset. If the task +was using MPOL_BIND and now none of its MPOL_BIND nodes are allowed +in the new cpuset, then the task will be essentially treated as if it +was MPOL_BIND bound to the new cpuset (even though its numa placement, +as queried by get_mempolicy(), doesn't change). If a task is moved +from one cpuset to another, then the kernel will adjust the tasks +memory placement, as above, the next time that the kernel attempts +to allocate a page of memory for that task. + +If a cpuset has its CPUs modified, then each task using that +cpuset does _not_ change its behavior automatically. In order to +minimize the impact on the critical scheduling code in the kernel, +tasks will continue to use their prior CPU placement until they +are rebound to their cpuset, by rewriting their pid to the 'tasks' +file of their cpuset. If a task had been bound to some subset of its +cpuset using the sched_setaffinity() call, and if any of that subset +is still allowed in its new cpuset settings, then the task will be +restricted to the intersection of the CPUs it was allowed on before, +and its new cpuset CPU placement. If, on the other hand, there is +no overlap between a tasks prior placement and its new cpuset CPU +placement, then the task will be allowed to run on any CPU allowed +in its new cpuset. If a task is moved from one cpuset to another, +its CPU placement is updated in the same way as if the tasks pid is +rewritten to the 'tasks' file of its current cpuset. + +In summary, the memory placement of a task whose cpuset is changed is +updated by the kernel, on the next allocation of a page for that task, +but the processor placement is not updated, until that tasks pid is +rewritten to the 'tasks' file of its cpuset. This is done to avoid +impacting the scheduler code in the kernel with a check for changes +in a tasks processor placement. + +There is an exception to the above. If hotplug funtionality is used +to remove all the CPUs that are currently assigned to a cpuset, +then the kernel will automatically update the cpus_allowed of all +tasks attached to CPUs in that cpuset with the online CPUs of the +nearest parent cpuset that still has some CPUs online. When memory +hotplug functionality for removing Memory Nodes is available, a +similar exception is expected to apply there as well. In general, +the kernel prefers to violate cpuset placement, over starving a task +that has had all its allowed CPUs or Memory Nodes taken offline. User +code should reconfigure cpusets to only refer to online CPUs and Memory +Nodes when using hotplug to add or remove such resources. + +To start a new job that is to be contained within a cpuset, the steps are: + + 1) mkdir /dev/cpuset + 2) mount -t cpuset none /dev/cpuset + 3) Create the new cpuset by doing mkdir's and write's (or echo's) in + the /dev/cpuset virtual file system. + 4) Start a task that will be the "founding father" of the new job. + 5) Attach that task to the new cpuset by writing its pid to the + /dev/cpuset tasks file for that cpuset. + 6) fork, exec or clone the job tasks from this founding father task. + +For example, the following sequence of commands will setup a cpuset +named "Charlie", containing just CPUs 2 and 3, and Memory Node 1, +and then start a subshell 'sh' in that cpuset: + + mount -t cpuset none /dev/cpuset + cd /dev/cpuset + mkdir Charlie + cd Charlie + /bin/echo 2-3 > cpus + /bin/echo 1 > mems + /bin/echo $$ > tasks + sh + # The subshell 'sh' is now running in cpuset Charlie + # The next line should display '/Charlie' + cat /proc/self/cpuset + +In the case that a change of cpuset includes wanting to move already +allocated memory pages, consider further the work of IWAMOTO +Toshihiro <iwamoto@valinux.co.jp> for page remapping and memory +hotremoval, which can be found at: + + http://people.valinux.co.jp/~iwamoto/mh.html + +The integration of cpusets with such memory migration is not yet +available. + +In the future, a C library interface to cpusets will likely be +available. For now, the only way to query or modify cpusets is +via the cpuset file system, using the various cd, mkdir, echo, cat, +rmdir commands from the shell, or their equivalent from C. + +The sched_setaffinity calls can also be done at the shell prompt using +SGI's runon or Robert Love's taskset. The mbind and set_mempolicy +calls can be done at the shell prompt using the numactl command +(part of Andi Kleen's numa package). + +2. Usage Examples and Syntax +============================ + +2.1 Basic Usage +--------------- + +Creating, modifying, using the cpusets can be done through the cpuset +virtual filesystem. + +To mount it, type: +# mount -t cpuset none /dev/cpuset + +Then under /dev/cpuset you can find a tree that corresponds to the +tree of the cpusets in the system. For instance, /dev/cpuset +is the cpuset that holds the whole system. + +If you want to create a new cpuset under /dev/cpuset: +# cd /dev/cpuset +# mkdir my_cpuset + +Now you want to do something with this cpuset. +# cd my_cpuset + +In this directory you can find several files: +# ls +cpus cpu_exclusive mems mem_exclusive tasks + +Reading them will give you information about the state of this cpuset: +the CPUs and Memory Nodes it can use, the processes that are using +it, its properties. By writing to these files you can manipulate +the cpuset. + +Set some flags: +# /bin/echo 1 > cpu_exclusive + +Add some cpus: +# /bin/echo 0-7 > cpus + +Now attach your shell to this cpuset: +# /bin/echo $$ > tasks + +You can also create cpusets inside your cpuset by using mkdir in this +directory. +# mkdir my_sub_cs + +To remove a cpuset, just use rmdir: +# rmdir my_sub_cs +This will fail if the cpuset is in use (has cpusets inside, or has +processes attached). + +2.2 Adding/removing cpus +------------------------ + +This is the syntax to use when writing in the cpus or mems files +in cpuset directories: + +# /bin/echo 1-4 > cpus -> set cpus list to cpus 1,2,3,4 +# /bin/echo 1,2,3,4 > cpus -> set cpus list to cpus 1,2,3,4 + +2.3 Setting flags +----------------- + +The syntax is very simple: + +# /bin/echo 1 > cpu_exclusive -> set flag 'cpu_exclusive' +# /bin/echo 0 > cpu_exclusive -> unset flag 'cpu_exclusive' + +2.4 Attaching processes +----------------------- + +# /bin/echo PID > tasks + +Note that it is PID, not PIDs. You can only attach ONE task at a time. +If you have several tasks to attach, you have to do it one after another: + +# /bin/echo PID1 > tasks +# /bin/echo PID2 > tasks + ... +# /bin/echo PIDn > tasks + + +3. Questions +============ + +Q: what's up with this '/bin/echo' ? +A: bash's builtin 'echo' command does not check calls to write() against + errors. If you use it in the cpuset file system, you won't be + able to tell whether a command succeeded or failed. + +Q: When I attach processes, only the first of the line gets really attached ! +A: We can only return one error code per call to write(). So you should also + put only ONE pid. + +4. Contact +========== + +Web: http://www.bullopensource.org/cpuset diff --git a/fs/proc/array.c b/fs/proc/array.c index 9a31caa01555..254a8eb6df15 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -73,6 +73,7 @@ #include <linux/highmem.h> #include <linux/file.h> #include <linux/times.h> +#include <linux/cpuset.h> #include <asm/uaccess.h> #include <asm/pgtable.h> @@ -300,6 +301,7 @@ int proc_pid_status(struct task_struct *task, char * buffer) } buffer = task_sig(task, buffer); buffer = task_cap(task, buffer); + buffer = cpuset_task_status_allowed(task, buffer); #if defined(CONFIG_ARCH_S390) buffer = task_show_regs(task, buffer); #endif diff --git a/fs/proc/base.c b/fs/proc/base.c index f863e4c7e628..1e4b41df3ab7 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -33,6 +33,7 @@ #include <linux/security.h> #include <linux/ptrace.h> #include <linux/seccomp.h> +#include <linux/cpuset.h> #include "internal.h" /* @@ -68,6 +69,9 @@ enum pid_directory_inos { #ifdef CONFIG_SCHEDSTATS PROC_TGID_SCHEDSTAT, #endif +#ifdef CONFIG_CPUSETS + PROC_TGID_CPUSET, +#endif #ifdef CONFIG_SECURITY PROC_TGID_ATTR, PROC_TGID_ATTR_CURRENT, @@ -102,6 +106,9 @@ enum pid_directory_inos { #ifdef CONFIG_SCHEDSTATS PROC_TID_SCHEDSTAT, #endif +#ifdef CONFIG_CPUSETS + PROC_TID_CPUSET, +#endif #ifdef CONFIG_SECURITY PROC_TID_ATTR, PROC_TID_ATTR_CURRENT, @@ -153,6 +160,9 @@ static struct pid_entry tgid_base_stuff[] = { #ifdef CONFIG_SCHEDSTATS E(PROC_TGID_SCHEDSTAT, "schedstat", S_IFREG|S_IRUGO), #endif +#ifdef CONFIG_CPUSETS + E(PROC_TGID_CPUSET, "cpuset", S_IFREG|S_IRUGO), +#endif E(PROC_TGID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO), E(PROC_TGID_OOM_ADJUST,"oom_adj", S_IFREG|S_IRUGO|S_IWUSR), #ifdef CONFIG_AUDITSYSCALL @@ -186,6 +196,9 @@ static struct pid_entry tid_base_stuff[] = { #ifdef CONFIG_SCHEDSTATS E(PROC_TID_SCHEDSTAT, "schedstat",S_IFREG|S_IRUGO), #endif +#ifdef CONFIG_CPUSETS + E(PROC_TID_CPUSET, "cpuset", S_IFREG|S_IRUGO), +#endif E(PROC_TID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO), E(PROC_TID_OOM_ADJUST, "oom_adj", S_IFREG|S_IRUGO|S_IWUSR), #ifdef CONFIG_AUDITSYSCALL @@ -1557,6 +1570,12 @@ static struct dentry *proc_pident_lookup(struct inode *dir, ei->op.proc_read = proc_pid_schedstat; break; #endif +#ifdef CONFIG_CPUSETS + case PROC_TID_CPUSET: + case PROC_TGID_CPUSET: + inode->i_fop = &proc_cpuset_operations; + break; +#endif case PROC_TID_OOM_SCORE: case PROC_TGID_OOM_SCORE: inode->i_fop = &proc_info_file_operations; diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h new file mode 100644 index 000000000000..5d3cb0dff332 --- /dev/null +++ b/include/linux/cpuset.h @@ -0,0 +1,64 @@ +#ifndef _LINUX_CPUSET_H +#define _LINUX_CPUSET_H +/* + * cpuset interface + * + * Copyright (C) 2003 BULL SA + * Copyright (C) 2004 Silicon Graphics, Inc. + * + */ + +#include <linux/sched.h> +#include <linux/cpumask.h> +#include <linux/nodemask.h> + +#ifdef CONFIG_CPUSETS + +extern int cpuset_init(void); +extern void cpuset_init_smp(void); +extern void cpuset_fork(struct task_struct *p); +extern void cpuset_exit(struct task_struct *p); +extern const cpumask_t cpuset_cpus_allowed(const struct task_struct *p); +void cpuset_init_current_mems_allowed(void); +void cpuset_update_current_mems_allowed(void); +void cpuset_restrict_to_mems_allowed(unsigned long *nodes); +int cpuset_zonelist_valid_mems_allowed(struct zonelist *zl); +int cpuset_zone_allowed(struct zone *z); +extern struct file_operations proc_cpuset_operations; +extern char *cpuset_task_status_allowed(struct task_struct *task, char *buffer); + +#else /* !CONFIG_CPUSETS */ + +static inline int cpuset_init(void) { return 0; } +static inline void cpuset_init_smp(void) {} +static inline void cpuset_fork(struct task_struct *p) {} +static inline void cpuset_exit(struct task_struct *p) {} + +static inline const cpumask_t cpuset_cpus_allowed(struct task_struct *p) +{ + return cpu_possible_map; +} + +static inline void cpuset_init_current_mems_allowed(void) {} +static inline void cpuset_update_current_mems_allowed(void) {} +static inline void cpuset_restrict_to_mems_allowed(unsigned long *nodes) {} + +static inline int cpuset_zonelist_valid_mems_allowed(struct zonelist *zl) +{ + return 1; +} + +static inline int cpuset_zone_allowed(struct zone *z) +{ + return 1; +} + +static inline char *cpuset_task_status_allowed(struct task_struct *task, + char *buffer) +{ + return buffer; +} + +#endif /* !CONFIG_CPUSETS */ + +#endif /* _LINUX_CPUSET_H */ diff --git a/include/linux/sched.h b/include/linux/sched.h index f564b18dbaed..637c88e5f5b8 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -14,6 +14,7 @@ #include <linux/thread_info.h> #include <linux/cpumask.h> #include <linux/errno.h> +#include <linux/nodemask.h> #include <asm/system.h> #include <asm/semaphore.h> @@ -514,6 +515,7 @@ extern void cpu_attach_domain(struct sched_domain *sd, int cpu); struct io_context; /* See blkdev.h */ void exit_io_context(void); +struct cpuset; #define NGROUPS_SMALL 32 #define NGROUPS_PER_BLOCK ((int)(PAGE_SIZE / sizeof(gid_t))) @@ -712,6 +714,11 @@ struct task_struct { struct mempolicy *mempolicy; short il_next; #endif +#ifdef CONFIG_CPUSETS + struct cpuset *cpuset; + nodemask_t mems_allowed; + int cpuset_mems_generation; +#endif }; static inline pid_t process_group(struct task_struct *tsk) diff --git a/init/Kconfig b/init/Kconfig index 97789f2c3111..ac693aac85d5 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -237,6 +237,16 @@ config IKCONFIG_PROC This option enables access to the kernel configuration file through /proc/config.gz. +config CPUSETS + bool "Cpuset support" + depends on SMP + help + This options will let you create and manage CPUSET's 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. + + Say N if unsure. menuconfig EMBEDDED bool "Configure standard kernel features (for small systems)" diff --git a/init/main.c b/init/main.c index 678a332d308a..0cd4d6137d49 100644 --- a/init/main.c +++ b/init/main.c @@ -41,6 +41,7 @@ #include <linux/kallsyms.h> #include <linux/writeback.h> #include <linux/cpu.h> +#include <linux/cpuset.h> #include <linux/efi.h> #include <linux/unistd.h> #include <linux/rmap.h> @@ -515,6 +516,8 @@ asmlinkage void __init start_kernel(void) #ifdef CONFIG_PROC_FS proc_root_init(); #endif + cpuset_init(); + check_bugs(); acpi_early_init(); /* before LAPIC and SMP init */ @@ -656,6 +659,8 @@ static int init(void * unused) smp_init(); sched_init_smp(); + cpuset_init_smp(); + /* * Do this before initcalls, because some drivers want to access * firmware files. diff --git a/kernel/Makefile b/kernel/Makefile index 0ac3efc9d071..d1a273ee6db6 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -18,6 +18,7 @@ obj-$(CONFIG_KALLSYMS) += kallsyms.o obj-$(CONFIG_PM) += power/ obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o obj-$(CONFIG_COMPAT) += compat.o +obj-$(CONFIG_CPUSETS) += cpuset.o obj-$(CONFIG_IKCONFIG) += configs.o obj-$(CONFIG_IKCONFIG_PROC) += configs.o obj-$(CONFIG_STOP_MACHINE) += stop_machine.o diff --git a/kernel/cpuset.c b/kernel/cpuset.c new file mode 100644 index 000000000000..44c03c666b01 --- /dev/null +++ b/kernel/cpuset.c @@ -0,0 +1,1534 @@ +/* + * kernel/cpuset.c + * + * Processor and Memory placement constraints for sets of tasks. + * + * Copyright (C) 2003 BULL SA. + * Copyright (C) 2004 Silicon Graphics, Inc. + * + * Portions derived from Patrick Mochel's sysfs code. + * sysfs is Copyright (c) 2001-3 Patrick Mochel + * Portions Copyright (c) 2004 Silicon Graphics, Inc. + * + * 2003-10-10 Written by Simon Derr <simon.derr@bull.net> + * 2003-10-22 Updates by Stephen Hemminger. + * 2004 May-July Rework by Paul Jackson <pj@sgi.com> + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of the Linux + * distribution for more details. + */ + +#include <linux/config.h> +#include <linux/cpu.h> +#include <linux/cpumask.h> +#include <linux/cpuset.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/kmod.h> +#include <linux/list.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/mount.h> +#include <linux/namei.h> +#include <linux/pagemap.h> +#include <linux/proc_fs.h> +#include <linux/sched.h> +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/smp_lock.h> +#include <linux/spinlock.h> +#include <linux/stat.h> +#include <linux/string.h> +#include <linux/time.h> +#include <linux/backing-dev.h> +#include <linux/sort.h> + +#include <asm/uaccess.h> +#include <asm/atomic.h> +#include <asm/semaphore.h> + +#define CPUSET_SUPER_MAGIC 0x27e0eb + +struct cpuset { + unsigned long flags; /* "unsigned long" so bitops work */ + cpumask_t cpus_allowed; /* CPUs allowed to tasks in cpuset */ + nodemask_t mems_allowed; /* Memory Nodes allowed to tasks */ + + atomic_t count; /* count tasks using this cpuset */ + + /* + * We link our 'sibling' struct into our parents 'children'. + * Our children link their 'sibling' into our 'children'. + */ + struct list_head sibling; /* my parents children */ + struct list_head children; /* my children */ + + struct cpuset *parent; /* my parent */ + struct dentry *dentry; /* cpuset fs entry */ + + /* + * Copy of global cpuset_mems_generation as of the most + * recent time this cpuset changed its mems_allowed. + */ + int mems_generation; +}; + +/* bits in struct cpuset flags field */ +typedef enum { + CS_CPU_EXCLUSIVE, + CS_MEM_EXCLUSIVE, + CS_REMOVED, + CS_NOTIFY_ON_RELEASE +} cpuset_flagbits_t; + +/* convenient tests for these bits */ +static inline int is_cpu_exclusive(const struct cpuset *cs) +{ + return !!test_bit(CS_CPU_EXCLUSIVE, &cs->flags); +} + +static inline int is_mem_exclusive(const struct cpuset *cs) +{ + return !!test_bit(CS_MEM_EXCLUSIVE, &cs->flags); +} + +static inline int is_removed(const struct cpuset *cs) +{ + return !!test_bit(CS_REMOVED, &cs->flags); +} + +static inline int notify_on_release(const struct cpuset *cs) +{ + return !!test_bit(CS_NOTIFY_ON_RELEASE, &cs->flags); +} + +/* + * Increment this atomic integer everytime any cpuset changes its + * mems_allowed value. Users of cpusets can track this generation + * number, and avoid having to lock and reload mems_allowed unless + * the cpuset they're using changes generation. + * + * A single, global generation is needed because attach_task() could + * reattach a task to a different cpuset, which must not have its + * generation numbers aliased with those of that tasks previous cpuset. + * + * Generations are needed for mems_allowed because one task cannot + * modify anothers memory placement. So we must enable every task, + * on every visit to __alloc_pages(), to efficiently check whether + * its current->cpuset->mems_allowed has changed, requiring an update + * of its current->mems_allowed. + */ +static atomic_t cpuset_mems_generation = ATOMIC_INIT(1); + +static struct cpuset top_cpuset = { + .flags = ((1 << CS_CPU_EXCLUSIVE) | (1 << CS_MEM_EXCLUSIVE)), + .cpus_allowed = CPU_MASK_ALL, + .mems_allowed = NODE_MASK_ALL, + .count = ATOMIC_INIT(0), + .sibling = LIST_HEAD_INIT(top_cpuset.sibling), + .children = LIST_HEAD_INIT(top_cpuset.children), + .parent = NULL, + .dentry = NULL, + .mems_generation = 0, +}; + +static struct vfsmount *cpuset_mount; +static struct super_block *cpuset_sb = NULL; + +/* + * cpuset_sem should be held by anyone who is depending on the children + * or sibling lists of any cpuset, or performing non-atomic operations + * on the flags or *_allowed values of a cpuset, such as raising the + * CS_REMOVED flag bit iff it is not already raised, or reading and + * conditionally modifying the *_allowed values. One kernel global + * cpuset semaphore should be sufficient - these things don't change + * that much. + * + * The code that modifies cpusets holds cpuset_sem across the entire + * operation, from cpuset_common_file_write() down, single threading + * all cpuset modifications (except for counter manipulations from + * fork and exit) across the system. This presumes that cpuset + * modifications are rare - better kept simple and safe, even if slow. + * + * The code that reads cpusets, such as in cpuset_common_file_read() + * and below, only holds cpuset_sem across small pieces of code, such + * as when reading out possibly multi-word cpumasks and nodemasks, as + * the risks are less, and the desire for performance a little greater. + * The proc_cpuset_show() routine needs to hold cpuset_sem to insure + * that no cs->dentry is NULL, as it walks up the cpuset tree to root. + * + * The hooks from fork and exit, cpuset_fork() and cpuset_exit(), don't + * (usually) grab cpuset_sem. These are the two most performance + * critical pieces of code here. The exception occurs on exit(), + * if the last task using a cpuset exits, and the cpuset was marked + * notify_on_release. In that case, the cpuset_sem is taken, the + * path to the released cpuset calculated, and a usermode call made + * to /sbin/cpuset_release_agent with the name of the cpuset (path + * relative to the root of cpuset file system) as the argument. + * + * A cpuset can only be deleted if both its 'count' of using tasks is + * zero, and its list of 'children' cpusets is empty. Since all tasks + * in the system use _some_ cpuset, and since there is always at least + * one task in the system (init, pid == 1), therefore, top_cpuset + * always has either children cpusets and/or using tasks. So no need + * for any special hack to ensure that top_cpuset cannot be deleted. + */ + +static DECLARE_MUTEX(cpuset_sem); + +/* + * A couple of forward declarations required, due to cyclic reference loop: + * cpuset_mkdir -> cpuset_create -> cpuset_populate_dir -> cpuset_add_file + * -> cpuset_create_file -> cpuset_dir_inode_operations -> cpuset_mkdir. + */ + +static int cpuset_mkdir(struct inode *dir, struct dentry *dentry, int mode); +static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry); + +static struct backing_dev_info cpuset_backing_dev_info = { + .ra_pages = 0, /* No readahead */ + .memory_backed = 1, /* Does not contribute to dirty memory */ +}; + +static struct inode *cpuset_new_inode(mode_t mode) +{ + struct inode *inode = new_inode(cpuset_sb); + + if (inode) { + inode->i_mode = mode; + inode->i_uid = current->fsuid; + inode->i_gid = current->fsgid; + inode->i_blksize = PAGE_CACHE_SIZE; + inode->i_blocks = 0; + inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; + inode->i_mapping->backing_dev_info = &cpuset_backing_dev_info; + } + return inode; +} + +static void cpuset_diput(struct dentry *dentry, struct inode *inode) +{ + /* is dentry a directory ? if so, kfree() associated cpuset */ + if (S_ISDIR(inode->i_mode)) { + struct cpuset *cs = dentry->d_fsdata; + BUG_ON(!(is_removed(cs))); + kfree(cs); + } + iput(inode); +} + +static struct dentry_operations cpuset_dops = { + .d_iput = cpuset_diput, +}; + +static struct dentry *cpuset_get_dentry(struct dentry *parent, const char *name) +{ + struct qstr qstr; + struct dentry *d; + + qstr.name = name; + qstr.len = strlen(name); + qstr.hash = full_name_hash(name, qstr.len); + d = lookup_hash(&qstr, parent); + if (!IS_ERR(d)) + d->d_op = &cpuset_dops; + return d; +} + +static void remove_dir(struct dentry *d) +{ + struct dentry *parent = dget(d->d_parent); + + d_delete(d); + simple_rmdir(parent->d_inode, d); + dput(parent); +} + +/* + * NOTE : the dentry must have been dget()'ed + */ +static void cpuset_d_remove_dir(struct dentry *dentry) +{ + struct list_head *node; + + spin_lock(&dcache_lock); + node = dentry->d_subdirs.next; + while (node != &dentry->d_subdirs) { + struct dentry *d = list_entry(node, struct dentry, d_child); + list_del_init(node); + if (d->d_inode) { + d = dget_locked(d); + spin_unlock(&dcache_lock); + d_delete(d); + simple_unlink(dentry->d_inode, d); + dput(d); + spin_lock(&dcache_lock); + } + node = dentry->d_subdirs.next; + } + list_del_init(&dentry->d_child); + spin_unlock(&dcache_lock); + remove_dir(dentry); +} + +static struct super_operations cpuset_ops = { + .statfs = simple_statfs, + .drop_inode = generic_delete_inode, +}; + +static int cpuset_fill_super(struct super_block *sb, void *unused_data, + int unused_silent) +{ + struct inode *inode; + struct dentry *root; + + sb->s_blocksize = PAGE_CACHE_SIZE; + sb->s_blocksize_bits = PAGE_CACHE_SHIFT; + sb->s_magic = CPUSET_SUPER_MAGIC; + sb->s_op = &cpuset_ops; + cpuset_sb = sb; + + inode = cpuset_new_inode(S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR); + if (inode) { + inode->i_op = &simple_dir_inode_operations; + inode->i_fop = &simple_dir_operations; + /* directories start off with i_nlink == 2 (for "." entry) */ + inode->i_nlink++; + } else { + return -ENOMEM; + } + + root = d_alloc_root(inode); + if (!root) { + iput(inode); + return -ENOMEM; + } + sb->s_root = root; + return 0; +} + +static struct super_block *cpuset_get_sb(struct file_system_type *fs_type, + int flags, const char *unused_dev_name, + void *data) +{ + return get_sb_single(fs_type, flags, data, cpuset_fill_super); +} + +static struct file_system_type cpuset_fs_type = { + .name = "cpuset", + .get_sb = cpuset_get_sb, + .kill_sb = kill_litter_super, +}; + +/* struct cftype: + * + * The files in the cpuset filesystem mostly have a very simple read/write + * handling, some common function will take care of it. Nevertheless some cases + * (read tasks) are special and therefore I define this structure for every + * kind of file. + * + * + * When reading/writing to a file: + * - the cpuset to use in file->f_dentry->d_parent->d_fsdata + * - the 'cftype' of the file is file->f_dentry->d_fsdata + */ + +struct cftype { + char *name; + int private; + int (*open) (struct inode *inode, struct file *file); + ssize_t (*read) (struct file *file, char __user *buf, size_t nbytes, + loff_t *ppos); + int (*write) (struct file *file, const char *buf, size_t nbytes, + loff_t *ppos); + int (*release) (struct inode *inode, struct file *file); +}; + +static inline struct cpuset *__d_cs(struct dentry *dentry) +{ + return dentry->d_fsdata; +} + +static inline struct cftype *__d_cft(struct dentry *dentry) +{ + return dentry->d_fsdata; +} + +/* + * Call with cpuset_sem held. Writes path of cpuset into buf. + * Returns 0 on success, -errno on error. + */ + +static int cpuset_path(const struct cpuset *cs, char *buf, int buflen) +{ + char *start; + + start = buf + buflen; + + *--start = '\0'; + for (;;) { + int len = cs->dentry->d_name.len; + if ((start -= len) < buf) + return -ENAMETOOLONG; + memcpy(start, cs->dentry->d_name.name, len); + cs = cs->parent; + if (!cs) + break; + if (!cs->parent) + continue; + if (--start < buf) + return -ENAMETOOLONG; + *start = '/'; + } + memmove(buf, start, buf + buflen - start); + return 0; +} + +/* + * Notify userspace when a cpuset is released, by running + * /sbin/cpuset_release_agent with the name of the cpuset (path + * relative to the root of cpuset file system) as the argument. + * + * Most likely, this user command will try to rmdir this cpuset. + * + * This races with the possibility that some other task will be + * attached to this cpuset before it is removed, or that some other + * user task will 'mkdir' a child cpuset of this cpuset. That's ok. + * The presumed 'rmdir' will fail quietly if this cpuset is no longer + * unused, and this cpuset will be reprieved from its death sentence, + * to continue to serve a useful existence. Next time it's released, + * we will get notified again, if it still has 'notify_on_release' set. + * + * Note final arg to call_usermodehelper() is 0 - that means + * don't wait. Since we are holding the global cpuset_sem here, + * and we are asking another thread (started from keventd) to rmdir a + * cpuset, we can't wait - or we'd deadlock with the removing thread + * on cpuset_sem. + */ + +static int cpuset_release_agent(char *cpuset_str) +{ + char *argv[3], *envp[3]; + int i; + + i = 0; + argv[i++] = "/sbin/cpuset_release_agent"; + argv[i++] = cpuset_str; + argv[i] = NULL; + + i = 0; + /* minimal command environment */ + envp[i++] = "HOME=/"; + envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; + envp[i] = NULL; + + return call_usermodehelper(argv[0], argv, envp, 0); +} + +/* + * Either cs->count of using tasks transitioned to zero, or the + * cs->children list of child cpusets just became empty. If this + * cs is notify_on_release() and now both the user count is zero and + * the list of children is empty, send notice to user land. + */ + +static void check_for_release(struct cpuset *cs) +{ + if (notify_on_release(cs) && atomic_read(&cs->count) == 0 && + list_empty(&cs->children)) { + char *buf; + + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!buf) + return; + if (cpuset_path(cs, buf, PAGE_SIZE) < 0) + goto out; + cpuset_release_agent(buf); +out: + kfree(buf); + } +} + +/* + * Return in *pmask the portion of a cpusets's cpus_allowed that + * are online. If none are online, walk up the cpuset hierarchy + * until we find one that does have some online cpus. If we get + * all the way to the top and still haven't found any online cpus, + * return cpu_online_map. Or if passed a NULL cs from an exit'ing + * task, return cpu_online_map. + * + * One way or another, we guarantee to return some non-empty subset + * of cpu_online_map. + * + * Call with cpuset_sem held. + */ + +static void guarantee_online_cpus(const struct cpuset *cs, cpumask_t *pmask) +{ + while (cs && !cpus_intersects(cs->cpus_allowed, cpu_online_map)) + cs = cs->parent; + if (cs) + cpus_and(*pmask, cs->cpus_allowed, cpu_online_map); + else + *pmask = cpu_online_map; + BUG_ON(!cpus_intersects(*pmask, cpu_online_map)); +} + +/* + * Return in *pmask the portion of a cpusets's mems_allowed that + * are online. If none are online, walk up the cpuset hierarchy + * until we find one that does have some online mems. If we get + * all the way to the top and still haven't found any online mems, + * return node_online_map. + * + * One way or another, we guarantee to return some non-empty subset + * of node_online_map. + * + * Call with cpuset_sem held. + */ + +static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask) +{ + while (cs && !nodes_intersects(cs->mems_allowed, node_online_map)) + cs = cs->parent; + if (cs) + nodes_and(*pmask, cs->mems_allowed, node_online_map); + else + *pmask = node_online_map; + BUG_ON(!nodes_intersects(*pmask, node_online_map)); +} + +/* + * is_cpuset_subset(p, q) - Is cpuset p a subset of cpuset q? + * + * One cpuset is a subset of another if all its allowed CPUs and + * Memory Nodes are a subset of the other, and its exclusive flags + * are only set if the other's are set. + */ + +static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q) +{ + return cpus_subset(p->cpus_allowed, q->cpus_allowed) && + nodes_subset(p->mems_allowed, q->mems_allowed) && + is_cpu_exclusive(p) <= is_cpu_exclusive(q) && + is_mem_exclusive(p) <= is_mem_exclusive(q); +} + +/* + * validate_change() - Used to validate that any proposed cpuset change + * follows the structural rules for cpusets. + * + * If we replaced the flag and mask values of the current cpuset + * (cur) with those values in the trial cpuset (trial), would + * our various subset and exclusive rules still be valid? Presumes + * cpuset_sem held. + * + * 'cur' is the address of an actual, in-use cpuset. Operations + * such as list traversal that depend on the actual address of the + * cpuset in the list must use cur below, not trial. + * + * 'trial' is the address of bulk structure copy of cur, with + * perhaps one or more of the fields cpus_allowed, mems_allowed, + * or flags changed to new, trial values. + * + * Return 0 if valid, -errno if not. + */ + +static int validate_change(const struct cpuset *cur, const struct cpuset *trial) +{ + struct cpuset *c, *par; + + /* Each of our child cpusets must be a subset of us */ + list_for_each_entry(c, &cur->children, sibling) { + if (!is_cpuset_subset(c, trial)) + return -EBUSY; + } + + /* Remaining checks don't apply to root cpuset */ + if ((par = cur->parent) == NULL) + return 0; + + /* We must be a subset of our parent cpuset */ + if (!is_cpuset_subset(trial, par)) + return -EACCES; + + /* If either I or some sibling (!= me) is exclusive, we can't overlap */ + list_for_each_entry(c, &par->children, sibling) { + if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) && + c != cur && + cpus_intersects(trial->cpus_allowed, c->cpus_allowed)) + return -EINVAL; + if ((is_mem_exclusive(trial) || is_mem_exclusive(c)) && + c != cur && + nodes_intersects(trial->mems_allowed, c->mems_allowed)) + return -EINVAL; + } + + return 0; +} + +static int update_cpumask(struct cpuset *cs, char *buf) +{ + struct cpuset trialcs; + int retval; + + trialcs = *cs; + retval = cpulist_parse(buf, trialcs.cpus_allowed); + if (retval < 0) + return retval; + cpus_and(trialcs.cpus_allowed, trialcs.cpus_allowed, cpu_online_map); + if (cpus_empty(trialcs.cpus_allowed)) + return -ENOSPC; + retval = validate_change(cs, &trialcs); + if (retval == 0) + cs->cpus_allowed = trialcs.cpus_allowed; + return retval; +} + +static int update_nodemask(struct cpuset *cs, char *buf) +{ + struct cpuset trialcs; + int retval; + + trialcs = *cs; + retval = nodelist_parse(buf, trialcs.mems_allowed); + if (retval < 0) + return retval; + nodes_and(trialcs.mems_allowed, trialcs.mems_allowed, node_online_map); + if (nodes_empty(trialcs.mems_allowed)) + return -ENOSPC; + retval = validate_change(cs, &trialcs); + if (retval == 0) { + cs->mems_allowed = trialcs.mems_allowed; + atomic_inc(&cpuset_mems_generation); + cs->mems_generation = atomic_read(&cpuset_mems_generation); + } + return retval; +} + +/* + * update_flag - read a 0 or a 1 in a file and update associated flag + * bit: the bit to update (CS_CPU_EXCLUSIVE, CS_MEM_EXCLUSIVE, + * CS_NOTIFY_ON_RELEASE) + * cs: the cpuset to update + * buf: the buffer where we read the 0 or 1 + */ + +static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, char *buf) +{ + int turning_on; + struct cpuset trialcs; + int err; + + turning_on = (simple_strtoul(buf, NULL, 10) != 0); + + trialcs = *cs; + if (turning_on) + set_bit(bit, &trialcs.flags); + else + clear_bit(bit, &trialcs.flags); + + err = validate_change(cs, &trialcs); + if (err == 0) { + if (turning_on) + set_bit(bit, &cs->flags); + else + clear_bit(bit, &cs->flags); + } + return err; +} + +static int attach_task(struct cpuset *cs, char *buf) +{ + pid_t pid; + struct task_struct *tsk; + struct cpuset *oldcs; + cpumask_t cpus; + + if (sscanf(buf, "%d", &pid) != 1) + return -EIO; + if (cpus_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)) + return -ENOSPC; + + if (pid) { + read_lock(&tasklist_lock); + + tsk = find_task_by_pid(pid); + if (!tsk) { + read_unlock(&tasklist_lock); + return -ESRCH; + } + + get_task_struct(tsk); + read_unlock(&tasklist_lock); + + if ((current->euid) && (current->euid != tsk->uid) + && (current->euid != tsk->suid)) { + put_task_struct(tsk); + return -EACCES; + } + } else { + tsk = current; + get_task_struct(tsk); + } + + task_lock(tsk); + oldcs = tsk->cpuset; + if (!oldcs) { + task_unlock(tsk); + put_task_struct(tsk); + return -ESRCH; + } + atomic_inc(&cs->count); + tsk->cpuset = cs; + task_unlock(tsk); + + guarantee_online_cpus(cs, &cpus); + set_cpus_allowed(tsk, cpus); + + put_task_struct(tsk); + if (atomic_dec_and_test(&oldcs->count)) + check_for_release(oldcs); + return 0; +} + +/* The various types of files and directories in a cpuset file system */ + +typedef enum { + FILE_ROOT, + FILE_DIR, + FILE_CPULIST, + FILE_MEMLIST, + FILE_CPU_EXCLUSIVE, + FILE_MEM_EXCLUSIVE, + FILE_NOTIFY_ON_RELEASE, + FILE_TASKLIST, +} cpuset_filetype_t; + +static ssize_t cpuset_common_file_write(struct file *file, const char *userbuf, + size_t nbytes, loff_t *unused_ppos) +{ + struct cpuset *cs = __d_cs(file->f_dentry->d_parent); + struct cftype *cft = __d_cft(file->f_dentry); + cpuset_filetype_t type = cft->private; + char *buffer; + int retval = 0; + + /* Crude upper limit on largest legitimate cpulist user might write. */ + if (nbytes > 100 + 6 * NR_CPUS) + return -E2BIG; + + /* +1 for nul-terminator */ + if ((buffer = kmalloc(nbytes + 1, GFP_KERNEL)) == 0) + return -ENOMEM; + + if (copy_from_user(buffer, userbuf, nbytes)) { + retval = -EFAULT; + goto out1; + } + buffer[nbytes] = 0; /* nul-terminate */ + + down(&cpuset_sem); + + if (is_removed(cs)) { + retval = -ENODEV; + goto out2; + } + + switch (type) { + case FILE_CPULIST: + retval = update_cpumask(cs, buffer); + break; + case FILE_MEMLIST: + retval = update_nodemask(cs, buffer); + break; + case FILE_CPU_EXCLUSIVE: + retval = update_flag(CS_CPU_EXCLUSIVE, cs, buffer); + break; + case FILE_MEM_EXCLUSIVE: + retval = update_flag(CS_MEM_EXCLUSIVE, cs, buffer); + break; + case FILE_NOTIFY_ON_RELEASE: + retval = update_flag(CS_NOTIFY_ON_RELEASE, cs, buffer); + break; + case FILE_TASKLIST: + retval = attach_task(cs, buffer); + break; + default: + retval = -EINVAL; + goto out2; + } + + if (retval == 0) + retval = nbytes; +out2: + up(&cpuset_sem); +out1: + kfree(buffer); + return retval; +} + +static ssize_t cpuset_file_write(struct file *file, const char *buf, + size_t nbytes, loff_t *ppos) +{ + ssize_t retval = 0; + struct cftype *cft = __d_cft(file->f_dentry); + if (!cft) + return -ENODEV; + + /* special function ? */ + if (cft->write) + retval = cft->write(file, buf, nbytes, ppos); + else + retval = cpuset_common_file_write(file, buf, nbytes, ppos); + + return retval; +} + +/* + * These ascii lists should be read in a single call, by using a user + * buffer large enough to hold the entire map. If read in smaller + * chunks, there is no guarantee of atomicity. Since the display format + * used, list of ranges of sequential numbers, is variable length, + * and since these maps can change value dynamically, one could read + * gibberish by doing partial reads while a list was changing. + * A single large read to a buffer that crosses a page boundary is + * ok, because the result being copied to user land is not recomputed + * across a page fault. + */ + +static int cpuset_sprintf_cpulist(char *page, struct cpuset *cs) +{ + cpumask_t mask; + + down(&cpuset_sem); + mask = cs->cpus_allowed; + up(&cpuset_sem); + + return cpulist_scnprintf(page, PAGE_SIZE, mask); +} + +static int cpuset_sprintf_memlist(char *page, struct cpuset *cs) +{ + nodemask_t mask; + + down(&cpuset_sem); + mask = cs->mems_allowed; + up(&cpuset_sem); + + return nodelist_scnprintf(page, PAGE_SIZE, mask); +} + +static ssize_t cpuset_common_file_read(struct file *file, char __user *buf, + size_t nbytes, loff_t *ppos) +{ + struct cftype *cft = __d_cft(file->f_dentry); + struct cpuset *cs = __d_cs(file->f_dentry->d_parent); + cpuset_filetype_t type = cft->private; + char *page; + ssize_t retval = 0; + char *s; + char *start; + size_t n; + + if (!(page = (char *)__get_free_page(GFP_KERNEL))) + return -ENOMEM; + + s = page; + + switch (type) { + case FILE_CPULIST: + s += cpuset_sprintf_cpulist(s, cs); + break; + case FILE_MEMLIST: + s += cpuset_sprintf_memlist(s, cs); + break; + case FILE_CPU_EXCLUSIVE: + *s++ = is_cpu_exclusive(cs) ? '1' : '0'; + break; + case FILE_MEM_EXCLUSIVE: + *s++ = is_mem_exclusive(cs) ? '1' : '0'; + break; + case FILE_NOTIFY_ON_RELEASE: + *s++ = notify_on_release(cs) ? '1' : '0'; + break; + default: + retval = -EINVAL; + goto out; + } + *s++ = '\n'; + *s = '\0'; + + start = page + *ppos; + n = s - start; + retval = n - copy_to_user(buf, start, min(n, nbytes)); + *ppos += retval; +out: + free_page((unsigned long)page); + return retval; +} + +static ssize_t cpuset_file_read(struct file *file, char *buf, size_t nbytes, + loff_t *ppos) +{ + ssize_t retval = 0; + struct cftype *cft = __d_cft(file->f_dentry); + if (!cft) + return -ENODEV; + + /* special function ? */ + if (cft->read) + retval = cft->read(file, buf, nbytes, ppos); + else + retval = cpuset_common_file_read(file, buf, nbytes, ppos); + + return retval; +} + +static int cpuset_file_open(struct inode *inode, struct file *file) +{ + int err; + struct cftype *cft; + + err = generic_file_open(inode, file); + if (err) + return err; + + cft = __d_cft(file->f_dentry); + if (!cft) + return -ENODEV; + if (cft->open) + err = cft->open(inode, file); + else + err = 0; + + return err; +} + +static int cpuset_file_release(struct inode *inode, struct file *file) +{ + struct cftype *cft = __d_cft(file->f_dentry); + if (cft->release) + return cft->release(inode, file); + return 0; +} + +static struct file_operations cpuset_file_operations = { + .read = cpuset_file_read, + .write = cpuset_file_write, + .llseek = generic_file_llseek, + .open = cpuset_file_open, + .release = cpuset_file_release, +}; + +static struct inode_operations cpuset_dir_inode_operations = { + .lookup = simple_lookup, + .mkdir = cpuset_mkdir, + .rmdir = cpuset_rmdir, +}; + +static int cpuset_create_file(struct dentry *dentry, int mode) +{ + struct inode *inode; + + if (!dentry) + return -ENOENT; + if (dentry->d_inode) + return -EEXIST; + + inode = cpuset_new_inode(mode); + if (!inode) + return -ENOMEM; + + if (S_ISDIR(mode)) { + inode->i_op = &cpuset_dir_inode_operations; + inode->i_fop = &simple_dir_operations; + + /* start off with i_nlink == 2 (for "." entry) */ + inode->i_nlink++; + } else if (S_ISREG(mode)) { + inode->i_size = 0; + inode->i_fop = &cpuset_file_operations; + } + + d_instantiate(dentry, inode); + dget(dentry); /* Extra count - pin the dentry in core */ + return 0; +} + +/* + * cpuset_create_dir - create a directory for an object. + * cs: the cpuset we create the directory for. + * It must have a valid ->parent field + * And we are going to fill its ->dentry field. + * name: The name to give to the cpuset directory. Will be copied. + * mode: mode to set on new directory. + */ + +static int cpuset_create_dir(struct cpuset *cs, const char *name, int mode) +{ + struct dentry *dentry = NULL; + struct dentry *parent; + int error = 0; + + parent = cs->parent->dentry; + dentry = cpuset_get_dentry(parent, name); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + error = cpuset_create_file(dentry, S_IFDIR | mode); + if (!error) { + dentry->d_fsdata = cs; + parent->d_inode->i_nlink++; + cs->dentry = dentry; + } + dput(dentry); + + return error; +} + +static int cpuset_add_file(struct dentry *dir, const struct cftype *cft) +{ + struct dentry *dentry; + int error; + + down(&dir->d_inode->i_sem); + dentry = cpuset_get_dentry(dir, cft->name); + if (!IS_ERR(dentry)) { + error = cpuset_create_file(dentry, 0644 | S_IFREG); + if (!error) + dentry->d_fsdata = (void *)cft; + dput(dentry); + } else + error = PTR_ERR(dentry); + up(&dir->d_inode->i_sem); + return error; +} + +/* + * Stuff for reading the 'tasks' file. + * + * Reading this file can return large amounts of data if a cpuset has + * *lots* of attached tasks. So it may need several calls to read(), + * but we cannot guarantee that the information we produce is correct + * unless we produce it entirely atomically. + * + * Upon tasks file open(), a struct ctr_struct is allocated, that + * will have a pointer to an array (also allocated here). The struct + * ctr_struct * is stored in file->private_data. Its resources will + * be freed by release() when the file is closed. The array is used + * to sprintf the PIDs and then used by read(). + */ + +/* cpusets_tasks_read array */ + +struct ctr_struct { + char *buf; + int bufsz; +}; + +/* + * Load into 'pidarray' up to 'npids' of the tasks using cpuset 'cs'. + * Return actual number of pids loaded. + */ +static inline int pid_array_load(pid_t *pidarray, int npids, struct cpuset *cs) +{ + int n = 0; + struct task_struct *g, *p; + + read_lock(&tasklist_lock); + + do_each_thread(g, p) { + if (p->cpuset == cs) { + pidarray[n++] = p->pid; + if (unlikely(n == npids)) + goto array_full; + } + } while_each_thread(g, p); + +array_full: + read_unlock(&tasklist_lock); + return n; +} + +static int cmppid(const void *a, const void *b) +{ + return *(pid_t *)a - *(pid_t *)b; +} + +/* + * Convert array 'a' of 'npids' pid_t's to a string of newline separated + * decimal pids in 'buf'. Don't write more than 'sz' chars, but return + * count 'cnt' of how many chars would be written if buf were large enough. + */ +static int pid_array_to_buf(char *buf, int sz, pid_t *a, int npids) +{ + int cnt = 0; + int i; + + for (i = 0; i < npids; i++) + cnt += snprintf(buf + cnt, max(sz - cnt, 0), "%d\n", a[i]); + return cnt; +} + +static int cpuset_tasks_open(struct inode *unused, struct file *file) +{ + struct cpuset *cs = __d_cs(file->f_dentry->d_parent); + struct ctr_struct *ctr; + pid_t *pidarray; + int npids; + char c; + + if (!(file->f_mode & FMODE_READ)) + return 0; + + ctr = kmalloc(sizeof(*ctr), GFP_KERNEL); + if (!ctr) + goto err0; + + /* + * If cpuset gets more users after we read count, we won't have + * enough space - tough. This race is indistinguishable to the + * caller from the case that the additional cpuset users didn't + * show up until sometime later on. + */ + npids = atomic_read(&cs->count); + pidarray = kmalloc(npids * sizeof(pid_t), GFP_KERNEL); + if (!pidarray) + goto err1; + + npids = pid_array_load(pidarray, npids, cs); + sort(pidarray, npids, sizeof(pid_t), cmppid, NULL); + + /* Call pid_array_to_buf() twice, first just to get bufsz */ + ctr->bufsz = pid_array_to_buf(&c, sizeof(c), pidarray, npids) + 1; + ctr->buf = kmalloc(ctr->bufsz, GFP_KERNEL); + if (!ctr->buf) + goto err2; + ctr->bufsz = pid_array_to_buf(ctr->buf, ctr->bufsz, pidarray, npids); + + kfree(pidarray); + file->private_data = ctr; + return 0; + +err2: + kfree(pidarray); +err1: + kfree(ctr); +err0: + return -ENOMEM; +} + +static ssize_t cpuset_tasks_read(struct file *file, char __user *buf, + size_t nbytes, loff_t *ppos) +{ + struct ctr_struct *ctr = file->private_data; + + if (*ppos + nbytes > ctr->bufsz) + nbytes = ctr->bufsz - *ppos; + if (copy_to_user(buf, ctr->buf + *ppos, nbytes)) + return -EFAULT; + *ppos += nbytes; + return nbytes; +} + +static int cpuset_tasks_release(struct inode *unused_inode, struct file *file) +{ + struct ctr_struct *ctr; + + if (file->f_mode & FMODE_READ) { + ctr = file->private_data; + kfree(ctr->buf); + kfree(ctr); + } + return 0; +} + +/* + * for the common functions, 'private' gives the type of file + */ + +static struct cftype cft_tasks = { + .name = "tasks", + .open = cpuset_tasks_open, + .read = cpuset_tasks_read, + .release = cpuset_tasks_release, + .private = FILE_TASKLIST, +}; + +static struct cftype cft_cpus = { + .name = "cpus", + .private = FILE_CPULIST, +}; + +static struct cftype cft_mems = { + .name = "mems", + .private = FILE_MEMLIST, +}; + +static struct cftype cft_cpu_exclusive = { + .name = "cpu_exclusive", + .private = FILE_CPU_EXCLUSIVE, +}; + +static struct cftype cft_mem_exclusive = { + .name = "mem_exclusive", + .private = FILE_MEM_EXCLUSIVE, +}; + +static struct cftype cft_notify_on_release = { + .name = "notify_on_release", + .private = FILE_NOTIFY_ON_RELEASE, +}; + +static int cpuset_populate_dir(struct dentry *cs_dentry) +{ + int err; + + if ((err = cpuset_add_file(cs_dentry, &cft_cpus)) < 0) + return err; + if ((err = cpuset_add_file(cs_dentry, &cft_mems)) < 0) + return err; + if ((err = cpuset_add_file(cs_dentry, &cft_cpu_exclusive)) < 0) + return err; + if ((err = cpuset_add_file(cs_dentry, &cft_mem_exclusive)) < 0) + return err; + if ((err = cpuset_add_file(cs_dentry, &cft_notify_on_release)) < 0) + return err; + if ((err = cpuset_add_file(cs_dentry, &cft_tasks)) < 0) + return err; + return 0; +} + +/* + * cpuset_create - create a cpuset + * parent: cpuset that will be parent of the new cpuset. + * name: name of the new cpuset. Will be strcpy'ed. + * mode: mode to set on new inode + * + * Must be called with the semaphore on the parent inode held + */ + +static long cpuset_create(struct cpuset *parent, const char *name, int mode) +{ + struct cpuset *cs; + int err; + + cs = kmalloc(sizeof(*cs), GFP_KERNEL); + if (!cs) + return -ENOMEM; + + down(&cpuset_sem); + cs->flags = 0; + if (notify_on_release(parent)) + set_bit(CS_NOTIFY_ON_RELEASE, &cs->flags); + cs->cpus_allowed = CPU_MASK_NONE; + cs->mems_allowed = NODE_MASK_NONE; + atomic_set(&cs->count, 0); + INIT_LIST_HEAD(&cs->sibling); + INIT_LIST_HEAD(&cs->children); + atomic_inc(&cpuset_mems_generation); + cs->mems_generation = atomic_read(&cpuset_mems_generation); + + cs->parent = parent; + + list_add(&cs->sibling, &cs->parent->children); + + err = cpuset_create_dir(cs, name, mode); + if (err < 0) + goto err; + + /* + * Release cpuset_sem before cpuset_populate_dir() because it + * will down() this new directory's i_sem and if we race with + * another mkdir, we might deadlock. + */ + up(&cpuset_sem); + + err = cpuset_populate_dir(cs->dentry); + /* If err < 0, we have a half-filled directory - oh well ;) */ + return 0; +err: + list_del(&cs->sibling); + up(&cpuset_sem); + kfree(cs); + return err; +} + +static int cpuset_mkdir(struct inode *dir, struct dentry *dentry, int mode) +{ + struct cpuset *c_parent = dentry->d_parent->d_fsdata; + + /* the vfs holds inode->i_sem already */ + return cpuset_create(c_parent, dentry->d_name.name, mode | S_IFDIR); +} + +static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry) +{ + struct cpuset *cs = dentry->d_fsdata; + struct dentry *d; + struct cpuset *parent; + + /* the vfs holds both inode->i_sem already */ + + down(&cpuset_sem); + if (atomic_read(&cs->count) > 0) { + up(&cpuset_sem); + return -EBUSY; + } + if (!list_empty(&cs->children)) { + up(&cpuset_sem); + return -EBUSY; + } + spin_lock(&cs->dentry->d_lock); + parent = cs->parent; + set_bit(CS_REMOVED, &cs->flags); + list_del(&cs->sibling); /* delete my sibling from parent->children */ + if (list_empty(&parent->children)) + check_for_release(parent); + d = dget(cs->dentry); + cs->dentry = NULL; + spin_unlock(&d->d_lock); + cpuset_d_remove_dir(d); + dput(d); + up(&cpuset_sem); + return 0; +} + +/** + * cpuset_init - initialize cpusets at system boot + * + * Description: Initialize top_cpuset and the cpuset internal file system, + **/ + +int __init cpuset_init(void) +{ + struct dentry *root; + int err; + + top_cpuset.cpus_allowed = CPU_MASK_ALL; + top_cpuset.mems_allowed = NODE_MASK_ALL; + + atomic_inc(&cpuset_mems_generation); + top_cpuset.mems_generation = atomic_read(&cpuset_mems_generation); + + init_task.cpuset = &top_cpuset; + + err = register_filesystem(&cpuset_fs_type); + if (err < 0) + goto out; + cpuset_mount = kern_mount(&cpuset_fs_type); + if (IS_ERR(cpuset_mount)) { + printk(KERN_ERR "cpuset: could not mount!\n"); + err = PTR_ERR(cpuset_mount); + cpuset_mount = NULL; + goto out; + } + root = cpuset_mount->mnt_sb->s_root; + root->d_fsdata = &top_cpuset; + root->d_inode->i_nlink++; + top_cpuset.dentry = root; + root->d_inode->i_op = &cpuset_dir_inode_operations; + err = cpuset_populate_dir(root); +out: + return err; +} + +/** + * cpuset_init_smp - initialize cpus_allowed + * + * Description: Finish top cpuset after cpu, node maps are initialized + **/ + +void __init cpuset_init_smp(void) +{ + top_cpuset.cpus_allowed = cpu_online_map; + top_cpuset.mems_allowed = node_online_map; +} + +/** + * cpuset_fork - attach newly forked task to its parents cpuset. + * @p: pointer to task_struct of forking parent process. + * + * Description: By default, on fork, a task inherits its + * parents cpuset. The pointer to the shared cpuset is + * automatically copied in fork.c by dup_task_struct(). + * This cpuset_fork() routine need only increment the usage + * counter in that cpuset. + **/ + +void cpuset_fork(struct task_struct *tsk) +{ + atomic_inc(&tsk->cpuset->count); +} + +/** + * cpuset_exit - detach cpuset from exiting task + * @tsk: pointer to task_struct of exiting process + * + * Description: Detach cpuset from @tsk and release it. + * + **/ + +void cpuset_exit(struct task_struct *tsk) +{ + struct cpuset *cs; + + task_lock(tsk); + cs = tsk->cpuset; + tsk->cpuset = NULL; + task_unlock(tsk); + + if (atomic_dec_and_test(&cs->count)) { + down(&cpuset_sem); + check_for_release(cs); + up(&cpuset_sem); + } +} + +/** + * cpuset_cpus_allowed - return cpus_allowed mask from a tasks cpuset. + * @tsk: pointer to task_struct from which to obtain cpuset->cpus_allowed. + * + * Description: Returns the cpumask_t cpus_allowed of the cpuset + * attached to the specified @tsk. Guaranteed to return some non-empty + * subset of cpu_online_map, even if this means going outside the + * tasks cpuset. + **/ + +const cpumask_t cpuset_cpus_allowed(const struct task_struct *tsk) +{ + cpumask_t mask; + + down(&cpuset_sem); + task_lock((struct task_struct *)tsk); + guarantee_online_cpus(tsk->cpuset, &mask); + task_unlock((struct task_struct *)tsk); + up(&cpuset_sem); + + return mask; +} + +void cpuset_init_current_mems_allowed(void) +{ + current->mems_allowed = NODE_MASK_ALL; +} + +/* + * If the current tasks cpusets mems_allowed changed behind our backs, + * update current->mems_allowed and mems_generation to the new value. + * Do not call this routine if in_interrupt(). + */ + +void cpuset_update_current_mems_allowed() +{ + struct cpuset *cs = current->cpuset; + + if (!cs) + return; /* task is exiting */ + if (current->cpuset_mems_generation != cs->mems_generation) { + down(&cpuset_sem); + guarantee_online_mems(cs, ¤t->mems_allowed); + current->cpuset_mems_generation = cs->mems_generation; + up(&cpuset_sem); + } +} + +void cpuset_restrict_to_mems_allowed(unsigned long *nodes) +{ + bitmap_and(nodes, nodes, nodes_addr(current->mems_allowed), + MAX_NUMNODES); +} + +/* + * Are any of the nodes on zonelist zl allowed in current->mems_allowed? + */ +int cpuset_zonelist_valid_mems_allowed(struct zonelist *zl) +{ + int i; + + for (i = 0; zl->zones[i]; i++) { + int nid = zl->zones[i]->zone_pgdat->node_id; + + if (node_isset(nid, current->mems_allowed)) + return 1; + } + return 0; +} + +/* + * Is 'current' valid, and is zone z allowed in current->mems_allowed? + */ +int cpuset_zone_allowed(struct zone *z) +{ + return in_interrupt() || + node_isset(z->zone_pgdat->node_id, current->mems_allowed); +} + +/* + * proc_cpuset_show() + * - Print tasks cpuset path into seq_file. + * - Used for /proc/<pid>/cpuset. + */ + +static int proc_cpuset_show(struct seq_file *m, void *v) +{ + struct cpuset *cs; + struct task_struct *tsk; + char *buf; + int retval = 0; + + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + tsk = m->private; + down(&cpuset_sem); + task_lock(tsk); + cs = tsk->cpuset; + task_unlock(tsk); + if (!cs) { + retval = -EINVAL; + goto out; + } + + retval = cpuset_path(cs, buf, PAGE_SIZE); + if (retval < 0) + goto out; + seq_puts(m, buf); + seq_putc(m, '\n'); +out: + up(&cpuset_sem); + kfree(buf); + return retval; +} + +static int cpuset_open(struct inode *inode, struct file *file) +{ + struct task_struct *tsk = PROC_I(inode)->task; + return single_open(file, proc_cpuset_show, tsk); +} + +struct file_operations proc_cpuset_operations = { + .open = cpuset_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +/* Display task cpus_allowed, mems_allowed in /proc/<pid>/status file. */ +char *cpuset_task_status_allowed(struct task_struct *task, char *buffer) +{ + buffer += sprintf(buffer, "Cpus_allowed:\t"); + buffer += cpumask_scnprintf(buffer, PAGE_SIZE, task->cpus_allowed); + buffer += sprintf(buffer, "\n"); + buffer += sprintf(buffer, "Mems_allowed:\t"); + buffer += nodemask_scnprintf(buffer, PAGE_SIZE, task->mems_allowed); + buffer += sprintf(buffer, "\n"); + return buffer; +} diff --git a/kernel/exit.c b/kernel/exit.c index ae320758b2f5..6dd4ebe1dd90 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -25,6 +25,7 @@ #include <linux/mount.h> #include <linux/proc_fs.h> #include <linux/mempolicy.h> +#include <linux/cpuset.h> #include <linux/syscalls.h> #include <asm/uaccess.h> @@ -820,6 +821,7 @@ fastcall NORET_TYPE void do_exit(long code) __exit_fs(tsk); exit_namespace(tsk); exit_thread(); + cpuset_exit(tsk); exit_keys(tsk); if (group_dead && tsk->signal->leader) diff --git a/kernel/fork.c b/kernel/fork.c index 8b00a09f598a..19a56e20f3c1 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -29,6 +29,7 @@ #include <linux/mman.h> #include <linux/fs.h> #include <linux/cpu.h> +#include <linux/cpuset.h> #include <linux/security.h> #include <linux/swap.h> #include <linux/syscalls.h> @@ -1069,6 +1070,8 @@ static task_t *copy_process(unsigned long clone_flags, if (unlikely(p->ptrace & PT_PTRACED)) __ptrace_link(p, current->parent); + cpuset_fork(p); + attach_pid(p, PIDTYPE_PID, p->pid); attach_pid(p, PIDTYPE_TGID, p->tgid); if (thread_group_leader(p)) { diff --git a/kernel/sched.c b/kernel/sched.c index 56bc8d9a9bda..2b4530eaa3c7 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -40,6 +40,7 @@ #include <linux/timer.h> #include <linux/rcupdate.h> #include <linux/cpu.h> +#include <linux/cpuset.h> #include <linux/percpu.h> #include <linux/kthread.h> #include <linux/seq_file.h> @@ -3539,6 +3540,7 @@ long sched_setaffinity(pid_t pid, cpumask_t new_mask) { task_t *p; int retval; + cpumask_t cpus_allowed; lock_cpu_hotplug(); read_lock(&tasklist_lock); @@ -3563,6 +3565,8 @@ long sched_setaffinity(pid_t pid, cpumask_t new_mask) !capable(CAP_SYS_NICE)) goto out_unlock; + cpus_allowed = cpuset_cpus_allowed(p); + cpus_and(new_mask, new_mask, cpus_allowed); retval = set_cpus_allowed(p, new_mask); out_unlock: @@ -4240,7 +4244,7 @@ static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *tsk) /* No more Mr. Nice Guy. */ if (dest_cpu == NR_CPUS) { - cpus_setall(tsk->cpus_allowed); + tsk->cpus_allowed = cpuset_cpus_allowed(tsk); dest_cpu = any_online_cpu(tsk->cpus_allowed); /* diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 1511786462f3..871d9584d9cf 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -67,6 +67,7 @@ #include <linux/sched.h> #include <linux/mm.h> #include <linux/nodemask.h> +#include <linux/cpuset.h> #include <linux/gfp.h> #include <linux/slab.h> #include <linux/string.h> @@ -167,6 +168,10 @@ static int get_nodes(unsigned long *nodes, unsigned long __user *nmask, if (copy_from_user(nodes, nmask, nlongs*sizeof(unsigned long))) return -EFAULT; nodes[nlongs-1] &= endmask; + /* Update current mems_allowed */ + cpuset_update_current_mems_allowed(); + /* Ignore nodes not set in current->mems_allowed */ + cpuset_restrict_to_mems_allowed(nodes); return mpol_check_policy(mode, nodes); } @@ -655,8 +660,10 @@ static struct zonelist *zonelist_policy(unsigned gfp, struct mempolicy *policy) break; case MPOL_BIND: /* Lower zones don't get a policy applied */ + /* Careful: current->mems_allowed might have moved */ if (gfp >= policy_zone) - return policy->v.zonelist; + if (cpuset_zonelist_valid_mems_allowed(policy->v.zonelist)) + return policy->v.zonelist; /*FALL THROUGH*/ case MPOL_INTERLEAVE: /* should not happen */ case MPOL_DEFAULT: @@ -747,6 +754,8 @@ alloc_page_vma(unsigned gfp, struct vm_area_struct *vma, unsigned long addr) { struct mempolicy *pol = get_vma_policy(vma, addr); + cpuset_update_current_mems_allowed(); + if (unlikely(pol->policy == MPOL_INTERLEAVE)) { unsigned nid; if (vma) { @@ -784,6 +793,8 @@ struct page *alloc_pages_current(unsigned gfp, unsigned order) { struct mempolicy *pol = current->mempolicy; + if (!in_interrupt()) + cpuset_update_current_mems_allowed(); if (!pol || in_interrupt()) pol = &default_policy; if (pol->policy == MPOL_INTERLEAVE) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index b68d7d8d7ac8..c8c1560871cf 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -31,6 +31,7 @@ #include <linux/topology.h> #include <linux/sysctl.h> #include <linux/cpu.h> +#include <linux/cpuset.h> #include <linux/nodemask.h> #include <linux/vmalloc.h> @@ -765,6 +766,9 @@ __alloc_pages(unsigned int gfp_mask, unsigned int order, classzone_idx, 0, 0)) continue; + if (!cpuset_zone_allowed(z)) + continue; + page = buffered_rmqueue(z, order, gfp_mask); if (page) goto got_pg; @@ -783,6 +787,9 @@ __alloc_pages(unsigned int gfp_mask, unsigned int order, gfp_mask & __GFP_HIGH)) continue; + if (!cpuset_zone_allowed(z)) + continue; + page = buffered_rmqueue(z, order, gfp_mask); if (page) goto got_pg; @@ -792,6 +799,8 @@ __alloc_pages(unsigned int gfp_mask, unsigned int order, if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) && !in_interrupt()) { /* go through the zonelist yet again, ignoring mins */ for (i = 0; (z = zones[i]) != NULL; i++) { + if (!cpuset_zone_allowed(z)) + continue; page = buffered_rmqueue(z, order, gfp_mask); if (page) goto got_pg; @@ -831,6 +840,9 @@ rebalance: gfp_mask & __GFP_HIGH)) continue; + if (!cpuset_zone_allowed(z)) + continue; + page = buffered_rmqueue(z, order, gfp_mask); if (page) goto got_pg; @@ -847,6 +859,9 @@ rebalance: classzone_idx, 0, 0)) continue; + if (!cpuset_zone_allowed(z)) + continue; + page = buffered_rmqueue(z, order, gfp_mask); if (page) goto got_pg; @@ -1490,6 +1505,7 @@ void __init build_all_zonelists(void) for_each_online_node(i) build_zonelists(NODE_DATA(i)); printk("Built %i zonelists\n", num_online_nodes()); + cpuset_init_current_mems_allowed(); } /* diff --git a/mm/vmscan.c b/mm/vmscan.c index e28c0232920d..aa9daa5651c2 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -30,6 +30,7 @@ #include <linux/rmap.h> #include <linux/topology.h> #include <linux/cpu.h> +#include <linux/cpuset.h> #include <linux/notifier.h> #include <linux/rwsem.h> @@ -865,6 +866,9 @@ shrink_caches(struct zone **zones, struct scan_control *sc) if (zone->present_pages == 0) continue; + if (!cpuset_zone_allowed(zone)) + continue; + zone->temp_priority = sc->priority; if (zone->prev_priority > sc->priority) zone->prev_priority = sc->priority; @@ -908,6 +912,9 @@ int try_to_free_pages(struct zone **zones, for (i = 0; zones[i] != NULL; i++) { struct zone *zone = zones[i]; + if (!cpuset_zone_allowed(zone)) + continue; + zone->temp_priority = DEF_PRIORITY; lru_pages += zone->nr_active + zone->nr_inactive; } @@ -948,8 +955,14 @@ int try_to_free_pages(struct zone **zones, blk_congestion_wait(WRITE, HZ/10); } out: - for (i = 0; zones[i] != 0; i++) - zones[i]->prev_priority = zones[i]->temp_priority; + for (i = 0; zones[i] != 0; i++) { + struct zone *zone = zones[i]; + + if (!cpuset_zone_allowed(zone)) + continue; + + zone->prev_priority = zone->temp_priority; + } return ret; } @@ -1210,6 +1223,8 @@ void wakeup_kswapd(struct zone *zone, int order) return; if (pgdat->kswapd_max_order < order) pgdat->kswapd_max_order = order; + if (!cpuset_zone_allowed(zone)) + return; if (!waitqueue_active(&zone->zone_pgdat->kswapd_wait)) return; wake_up_interruptible(&zone->zone_pgdat->kswapd_wait); |