| /linux/Documentation/translations/zh_CN/userspace-api/ |
| A D | futex2.rst | 16 futex，或者称为快速用户互斥锁（fast user mutex），是一组允许用户空间创建高性能同步
20 futex2是初代futex系统调用的后续版本，旨在克服原有接口的限制。
28 等待一个futex数组，可由其中任意一个唤醒::
41 地址， ``val`` 为期望值， ``flags`` 为指定的类型（如private）和futex的大小。
58 - 某个列表中的futex被唤醒，返回那个被唤醒的futex的索引。
70 futex的类型
73 futex既可以是私有的也可以是共享的。私有用于多个进程共享同样的内存空间，并且futex的虚拟
74 地址对所有进程都是一样的。这允许在内核中进行优化。要使用私有futex，需要在futex标志中指定
75 ``FUTEX_PRIVATE_FLAG`` 。对于那些不在同一内存空间共享的进程，可以让同一个futex拥有不同
77 的行为，而且对私有futex和共享futex都适用。
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| /linux/tools/testing/selftests/futex/functional/ |
| A D | futex_wait.c | 20 void *futex; variable
42 if (futex_wait(futex, 0, &to, flags)) in waiterfn()
56 futex = &f_private; in main()
80 info("Calling private futex_wait on futex: %p\n", futex); in main()
86 info("Calling private futex_wake on futex: %p\n", futex); in main()
87 res = futex_wake(futex, 1, FUTEX_PRIVATE_FLAG); in main()
106 futex = shared_data; in main()
108 info("Calling shared (page anon) futex_wait on futex: %p\n", futex); in main()
114 info("Calling shared (page anon) futex_wake on futex: %p\n", futex); in main()
115 res = futex_wake(futex, 1, 0); in main()
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| /linux/tools/testing/selftests/futex/include/ |
| A D | futextest.h | 70 #define futex(uaddr, op, val, timeout, uaddr2, val3, opflags) \ macro
80 return futex(uaddr, FUTEX_WAIT, val, timeout, NULL, 0, opflags); in futex_wait()
90 return futex(uaddr, FUTEX_WAKE, nr_wake, NULL, NULL, 0, opflags); in futex_wake()
101 return futex(uaddr, FUTEX_WAIT_BITSET, val, timeout, NULL, bitset, in futex_wait_bitset()
112 return futex(uaddr, FUTEX_WAKE_BITSET, nr_wake, NULL, NULL, bitset, in futex_wake_bitset()
124 return futex(uaddr, FUTEX_LOCK_PI, detect, timeout, NULL, 0, opflags); in futex_lock_pi()
133 return futex(uaddr, FUTEX_UNLOCK_PI, 0, NULL, NULL, 0, opflags); in futex_unlock_pi()
143 return futex(uaddr, FUTEX_WAKE_OP, nr_wake, nr_wake2, uaddr2, wake_op, in futex_wake_op()
159 return futex(uaddr, FUTEX_REQUEUE, nr_wake, nr_requeue, uaddr2, 0, in futex_requeue()
172 return futex(uaddr, FUTEX_CMP_REQUEUE, nr_wake, nr_requeue, uaddr2, in futex_cmp_requeue()
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| /linux/Documentation/locking/ |
| A D | pi-futex.rst | 7 - in the user-space fastpath a PI-enabled futex involves no kernel work
64 locks (such as futex-based pthread mutexes) is priority inheritance:
80 normal futex-based locks: a 0 value means unlocked, and a value==TID
85 To handle the slowpath, we have added two new futex ops:
92 remaining work: if there is no futex-queue attached to the futex address
94 own TID into the futex value], and attaches a 'PI state' structure to
98 futex value. Then this task tries to lock the rt-mutex, on which it
101 perform - it now owns the lock, and futex value contains
114 there is no prior 'registration' of a PI-futex. [which is not quite
118 properties of futexes, and all four combinations are possible: futex,
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| A D | robust-futexes.rst | 15 A futex is in essence a user-space address, e.g. a 32-bit lock variable
20 creates a 'futex queue' internally, so that it can later on match up the
22 When the owner thread releases the futex, it notices (via the variable
25 taken and released the lock, the futex is again back to 'uncontended'
27 completely forgets that there ever was a futex at that address. This
44 the kernel cannot help with the cleanup: if there is no 'futex queue'
51 is needed to release that futex based lock. This is one of the leading
109 list is done after the futex is acquired by glibc, there is a few
191 If a futex is found to be held at exit time, the kernel sets the
192 following bit of the futex word::
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| A D | index.rst | 21 pi-futex
22 futex-requeue-pi
26 robust-futex-ABI
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| A D | robust-futex-ABI.rst | 2 The robust futex ABI
26 waiting on a particular futex, and waking up the next waiter on a
27 particular futex.
80 lock variable used by the futex mechanism, in conjunction with
85 For each futex lock currently held by a thread, if it wants this
91 that lock using the futex mechanism.
118 existing futex mechanism to wait for, and wakeup, locks. The kernels
143 2) acquire the futex lock,
153 3) release the futex lock, and
162 1) if bit 31 (0x80000000) is set in that word, then attempt a futex
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| A D | futex-requeue-pi.rst | 5 Requeueing of tasks from a non-PI futex to a PI futex requires
56 user space already holding the PI futex. The glibc implementation
105 and pthread_cond_timedwait()) to block on the initial futex and wait
106 to be requeued to a PI-aware futex. The implementation is the
116 PI futex on behalf of the top waiter. If it can, this waiter is
118 nr_wake+nr_requeue tasks to the PI futex, calling
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| /linux/tools/perf/bench/ |
| A D | futex-lock-pi.c | 29 u_int32_t *futex; member
97 ret = futex_lock_pi(w->futex, NULL, futex_flag); in workerfn()
102 w->tid, w->futex, ret); in workerfn()
110 ret = futex_unlock_pi(w->futex, futex_flag); in workerfn()
113 w->tid, w->futex, ret); in workerfn()
141 worker[i].futex = calloc(1, sizeof(u_int32_t)); in create_threads()
142 if (!worker[i].futex) in create_threads()
145 worker[i].futex = &global_futex; in create_threads()
239 worker[i].tid, worker[i].futex, t); in bench_futex_lock_pi()
242 zfree(&worker[i].futex); in bench_futex_lock_pi()
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| A D | futex-hash.c | 45 u_int32_t *futex; member
92 ret = futex_wait(&w->futex[i], 1234, NULL, futex_flag); in workerfn()
184 worker[i].futex = calloc(params.nfutexes, sizeof(*worker[i].futex)); in bench_futex_hash()
185 if (!worker[i].futex) in bench_futex_hash()
234 worker[i].tid, &worker[i].futex[0], t); in bench_futex_hash()
237 worker[i].tid, &worker[i].futex[0], in bench_futex_hash()
238 &worker[i].futex[params.nfutexes-1], t); in bench_futex_hash()
241 zfree(&worker[i].futex); in bench_futex_hash()
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| A D | Build | 6 perf-bench-y += futex-hash.o
7 perf-bench-y += futex-wake.o
8 perf-bench-y += futex-wake-parallel.o
9 perf-bench-y += futex-requeue.o
10 perf-bench-y += futex-lock-pi.o
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| A D | futex-wake-parallel.c | 49 static u_int32_t futex = 0; variable
86 waker->nwoken = futex_wake(&futex, nwakes, futex_flag); in waking_workerfn()
140 if (futex_wait(&futex, 0, NULL, futex_flag) != EINTR) in blocked_workerfn()
297 &futex, params.nwakes, nwakes); in bench_futex_wake_parallel()
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| /linux/Documentation/userspace-api/ |
| A D | futex2.rst | 9 futex, or fast user mutex, is a set of syscalls to allow userspace to create
14 futex2 is a followup version of the initial futex syscall, designed to overcome
37 and ``flags`` to specify the type (e.g. private) and size of futex.
59 - Some futex at the list was woken, returning the index of some waked futex.
61 An example of how to use the interface can be found at ``tools/testing/selftests/futex/functional/f…
71 Types of futex
74 A futex can be either private or shared. Private is used for processes that
75 shares the same memory space and the virtual address of the futex will be the
77 private futexes, it's necessary to specify ``FUTEX_PRIVATE_FLAG`` in the futex
79 have different virtual addresses for the same futex (using, for instance, a
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| /linux/kernel/futex/ |
| A D | waitwake.c | 708 restart->futex.uaddr = uaddr; in futex_wait()
709 restart->futex.val = val; in futex_wait()
710 restart->futex.time = *abs_time; in futex_wait()
711 restart->futex.bitset = bitset; in futex_wait()
712 restart->futex.flags = flags | FLAGS_HAS_TIMEOUT; in futex_wait()
722 u32 __user *uaddr = restart->futex.uaddr; in futex_wait_restart()
725 if (restart->futex.flags & FLAGS_HAS_TIMEOUT) { in futex_wait_restart()
726 t = restart->futex.time; in futex_wait_restart()
731 return (long)futex_wait(uaddr, restart->futex.flags, in futex_wait_restart()
732 restart->futex.val, tp, restart->futex.bitset); in futex_wait_restart()
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| /linux/Documentation/translations/zh_CN/locking/ |
| A D | index.rst | 31 * pi-futex
32 * futex-requeue-pi
36 * robust-futex-ABI
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| /linux/tools/testing/selftests/powerpc/benchmarks/ |
| A D | futex_bench.c | 18 #define futex(A, B, C, D, E, F) syscall(__NR_futex, A, B, C, D, E, F) macro
29 futex(&addr, FUTEX_WAKE, 1, NULL, NULL, 0); in test_futex()
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| /linux/tools/testing/selftests/futex/ |
| A D | README | 3 Futex Test is intended to thoroughly test the Linux kernel futex system call
6 Functional tests shall test the documented behavior of the futex operation
54 based on the primary futex operation they test. Eventually this will become a
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| /linux/tools/perf/scripts/python/bin/ |
| A D | futex-contention-report | 4 perf script $@ -s "$PERF_EXEC_PATH"/scripts/python/futex-contention.py
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| /linux/tools/testing/selftests/timens/ |
| A D | .gitignore | 4 futex
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| A D | Makefile | 1 TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec futex vfork_exec
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| /linux/include/linux/ |
| A D | restart_block.h | 37 } futex; member
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| /linux/Documentation/translations/zh_CN/ |
| A D | glossary.rst | 21 * futex: 快速用户互斥锁。（fast user mutex）
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| /linux/tools/perf/Documentation/ |
| A D | perf-bench.txt | 61 'futex'::
228 SUITES FOR 'futex'
243 Suite for evaluating futex lock_pi calls.
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| /linux/io_uring/ |
| A D | Makefile | 18 obj-$(CONFIG_FUTEX) += futex.o
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| /linux/include/asm-generic/ |
| A D | Kbuild | 25 mandatory-y += futex.h
|