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authorJeff Roberson <jeff@FreeBSD.org>2008-03-02 07:39:22 +0000
committerJeff Roberson <jeff@FreeBSD.org>2008-03-02 07:39:22 +0000
commitd7f687fc9b6513875325f8aad4c9a92444984b96 (patch)
tree08c6ca461fae4d8b5341e887a545b2d167f50daf /sys/sys/cpuset.h
parent885d51a38a7d27227219d37738b67fd39064ec6a (diff)
downloadsrc-d7f687fc9b6513875325f8aad4c9a92444984b96.tar.gz
src-d7f687fc9b6513875325f8aad4c9a92444984b96.zip
Add cpuset, an api for thread to cpu binding and cpu resource grouping
and assignment. - Add a reference to a struct cpuset in each thread that is inherited from the thread that created it. - Release the reference when the thread is destroyed. - Add prototypes for syscalls and macros for manipulating cpusets in sys/cpuset.h - Add syscalls to create, get, and set new numbered cpusets: cpuset(), cpuset_{get,set}id() - Add syscalls for getting and setting affinity masks for cpusets or individual threads: cpuid_{get,set}affinity() - Add types for the 'level' and 'which' parameters for the cpuset. This will permit expansion of the api to cover cpu masks for other objects identifiable with an id_t integer. For example, IRQs and Jails may be coming soon. - The root set 0 contains all valid cpus. All thread initially belong to cpuset 1. This permits migrating all threads off of certain cpus to reserve them for special applications. Sponsored by: Nokia Discussed with: arch, rwatson, brooks, davidxu, deischen Reviewed by: antoine
Notes
Notes: svn path=/head/; revision=176730
Diffstat (limited to 'sys/sys/cpuset.h')
-rw-r--r--sys/sys/cpuset.h146
1 files changed, 146 insertions, 0 deletions
diff --git a/sys/sys/cpuset.h b/sys/sys/cpuset.h
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+/*-
+ * Copyright (c) 2008, Jeffrey Roberson <jeff@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice unmodified, this list of conditions, and the following
+ * disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _SYS_CPUSET_H_
+#define _SYS_CPUSET_H_
+
+#ifdef _KERNEL
+#define CPU_SETSIZE MAXCPU
+#endif
+
+#define CPU_MAXSIZE 128
+
+#ifndef CPU_SETSIZE
+#define CPU_SETSIZE CPU_MAXSIZE
+#endif
+
+#define _NCPUBITS (sizeof(long) * NBBY) /* bits per mask */
+#define _NCPUWORDS howmany(CPU_SETSIZE, _NCPUBITS)
+
+typedef struct _cpuset {
+ long __bits[howmany(CPU_SETSIZE, _NCPUBITS)];
+} cpuset_t;
+
+#define __cpuset_mask(n) ((long)1 << ((n) % _NCPUBITS))
+#define CPU_CLR(n, p) ((p)->__bits[(n)/_NCPUBITS] &= ~__cpuset_mask(n))
+#define CPU_COPY(f, t) (void)(*(t) = *(f))
+#define CPU_ISSET(n, p) (((p)->__bits[(n)/_NCPUBITS] & __cpuset_mask(n)) != 0)
+#define CPU_SET(n, p) ((p)->__bits[(n)/_NCPUBITS] |= __cpuset_mask(n))
+#define CPU_ZERO(p) do { \
+ __size_t __i; \
+ for (__i = 0; __i < _NCPUWORDS; __i++) \
+ (p)->__bits[__i] = 0; \
+} while (0)
+
+#define CPU_EMPTY(p) __extension__ ({ \
+ __size_t __i; \
+ for (__i = 0; __i < _NCPUWORDS; __i++) \
+ if ((p)->__bits[__i]) \
+ break; \
+ __i == _NCPUWORDS; \
+})
+
+#define CPU_OR(d, s) do { \
+ __size_t __i; \
+ for (__i = 0; __i < _NCPUWORDS; __i++) \
+ (d)->__bits[__i] |= (s)->__bits[__i]; \
+} while (0)
+
+#define CPU_AND(d, s) do { \
+ __size_t __i; \
+ for (__i = 0; __i < _NCPUWORDS; __i++) \
+ (d)->__bits[__i] &= (s)->__bits[__i]; \
+} while (0)
+
+#define CPU_NAND(d, s) do { \
+ __size_t __i; \
+ for (__i = 0; __i < _NCPUWORDS; __i++) \
+ (d)->__bits[__i] &= ~(s)->__bits[__i]; \
+} while (0)
+
+/*
+ * Valid cpulevel_t values.
+ */
+#define CPU_LEVEL_ROOT 1 /* All system cpus. */
+#define CPU_LEVEL_CPUSET 2 /* Available cpus for which. */
+#define CPU_LEVEL_WHICH 3 /* Actual mask/id for which. */
+
+/*
+ * Valid cpuwhich_t values.
+ */
+#define CPU_WHICH_TID 1 /* Specifies a thread id. */
+#define CPU_WHICH_PID 2 /* Specifies a process id. */
+#define CPU_WHICH_CPUSET 3 /* Specifies a set id. */
+
+/*
+ * Reserved cpuset identifiers.
+ */
+#define CPUSET_INVALID -1
+#define CPUSET_DEFAULT 0
+
+#ifdef _KERNEL
+LIST_HEAD(setlist, cpuset);
+
+/*
+ * cpusets encapsulate cpu binding information for one or more threads.
+ *
+ * a - Accessed with atomics.
+ * s - Set at creation, never modified. Only a ref required to read.
+ * c - Locked internally by a cpuset lock.
+ *
+ * The bitmask is only modified while holding the cpuset lock. It may be
+ * read while only a reference is held but the consumer must be prepared
+ * to deal with inconsistent results.
+ */
+struct cpuset {
+ cpuset_t cs_mask; /* bitmask of valid cpus. */
+ volatile u_int cs_ref; /* (a) Reference count. */
+ int cs_flags; /* (s) Flags from below. */
+ cpusetid_t cs_id; /* (s) Id or INVALID. */
+ struct cpuset *cs_parent; /* (s) Pointer to our parent. */
+ LIST_ENTRY(cpuset) cs_link; /* (c) All identified sets. */
+ LIST_ENTRY(cpuset) cs_siblings; /* (c) Sibling set link. */
+ struct setlist cs_children; /* (c) List of children. */
+};
+
+#define CPU_SET_ROOT 0x0001 /* Set is a root set. */
+#define CPU_SET_RDONLY 0x0002 /* No modification allowed. */
+
+struct cpuset *cpuset_thread0(void);
+struct cpuset *cpuset_ref(struct cpuset *);
+void cpuset_rel(struct cpuset *);
+#else
+__BEGIN_DECLS
+int cpuset(cpusetid_t *);
+int cpuset_setid(cpuwhich_t, id_t, cpusetid_t);
+int cpuset_getid(cpulevel_t, cpuwhich_t, id_t, cpusetid_t *);
+int cpuset_getaffinity(cpulevel_t, cpuwhich_t, id_t, int, cpuset_t *);
+int cpuset_setaffinity(cpulevel_t, cpuwhich_t, id_t, int, cpuset_t *);
+__END_DECLS
+#endif
+#endif /* !_SYS_CPUSET_H_ */