[75f3522] | 1 | // |
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo |
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| 3 | // |
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| 4 | // The contents of this file are covered under the licence agreement in the |
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| 5 | // file "LICENCE" distributed with Cforall. |
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| 6 | // |
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[73abe95] | 7 | // kernel_private.hfa -- |
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[75f3522] | 8 | // |
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| 9 | // Author : Thierry Delisle |
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| 10 | // Created On : Mon Feb 13 12:27:26 2017 |
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[6b0b624] | 11 | // Last Modified By : Peter A. Buhr |
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[fd9b524] | 12 | // Last Modified On : Wed Aug 12 08:21:33 2020 |
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| 13 | // Update Count : 9 |
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[75f3522] | 14 | // |
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| 15 | |
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[6b0b624] | 16 | #pragma once |
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[75f3522] | 17 | |
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[3489ea6] | 18 | #if !defined(__cforall_thread__) |
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| 19 | #error kernel_private.hfa should only be included in libcfathread source |
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| 20 | #endif |
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| 21 | |
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[58b6d1b] | 22 | #include "kernel.hfa" |
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| 23 | #include "thread.hfa" |
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[75f3522] | 24 | |
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[73abe95] | 25 | #include "alarm.hfa" |
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[8834751] | 26 | #include "stats.hfa" |
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[fa21ac9] | 27 | |
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[3489ea6] | 28 | extern "C" { |
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| 29 | #if defined(CFA_HAVE_LINUX_LIBRSEQ) |
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| 30 | #include <rseq/rseq.h> |
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| 31 | #elif defined(CFA_HAVE_LINUX_RSEQ_H) |
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[3814957] | 32 | // #include <linux/rseq.h> |
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[3489ea6] | 33 | #else |
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| 34 | #ifndef _GNU_SOURCE |
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| 35 | #error kernel_private requires gnu_source |
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| 36 | #endif |
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| 37 | #include <sched.h> |
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| 38 | #endif |
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| 39 | } |
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| 40 | |
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[75f3522] | 41 | //----------------------------------------------------------------------------- |
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| 42 | // Scheduler |
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[1c273d0] | 43 | extern "C" { |
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[2026bb6] | 44 | void disable_interrupts() OPTIONAL_THREAD; |
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[a3821fa] | 45 | void enable_interrupts( bool poll = true ); |
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[1c273d0] | 46 | } |
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| 47 | |
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[254ad1b] | 48 | void schedule_thread$( $thread * ) __attribute__((nonnull (1))); |
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[75f3522] | 49 | |
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[8fc652e0] | 50 | extern bool __preemption_enabled(); |
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| 51 | |
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[5afb49a] | 52 | //release/wake-up the following resources |
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| 53 | void __thread_finish( $thread * thrd ); |
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[db6f06a] | 54 | |
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[3489ea6] | 55 | //----------------------------------------------------------------------------- |
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| 56 | // Hardware |
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| 57 | |
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| 58 | #if defined(CFA_HAVE_LINUX_LIBRSEQ) |
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| 59 | // No data needed |
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| 60 | #elif defined(CFA_HAVE_LINUX_RSEQ_H) |
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| 61 | extern "Cforall" { |
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[3814957] | 62 | // extern __attribute__((aligned(128))) thread_local volatile struct rseq __cfaabi_rseq; |
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[3489ea6] | 63 | } |
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| 64 | #else |
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| 65 | // No data needed |
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| 66 | #endif |
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| 67 | |
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| 68 | static inline int __kernel_getcpu() { |
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| 69 | /* paranoid */ verify( ! __preemption_enabled() ); |
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| 70 | #if defined(CFA_HAVE_LINUX_LIBRSEQ) |
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| 71 | return rseq_current_cpu_raw(); |
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| 72 | #elif defined(CFA_HAVE_LINUX_RSEQ_H) |
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[3814957] | 73 | // return __cfaabi_rseq.cpu_id; |
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[3489ea6] | 74 | #else |
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| 75 | return sched_getcpu(); |
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| 76 | #endif |
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| 77 | } |
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| 78 | |
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[75f3522] | 79 | //----------------------------------------------------------------------------- |
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| 80 | // Processor |
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| 81 | void main(processorCtx_t *); |
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[85b1deb] | 82 | |
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[8c50aed] | 83 | void * __create_pthread( pthread_t *, void * (*)(void *), void * ); |
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[bfcf6b9] | 84 | void __destroy_pthread( pthread_t pthread, void * stack, void ** retval ); |
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[1805b1b] | 85 | |
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[6502a2b] | 86 | extern cluster * mainCluster; |
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| 87 | |
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[75f3522] | 88 | //----------------------------------------------------------------------------- |
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| 89 | // Threads |
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| 90 | extern "C" { |
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[c7a900a] | 91 | void __cfactx_invoke_thread(void (*main)(void *), void * this); |
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[75f3522] | 92 | } |
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| 93 | |
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[f7d6bb0] | 94 | __cfaabi_dbg_debug_do( |
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[ac2b598] | 95 | extern void __cfaabi_dbg_thread_register ( $thread * thrd ); |
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| 96 | extern void __cfaabi_dbg_thread_unregister( $thread * thrd ); |
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[f7d6bb0] | 97 | ) |
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| 98 | |
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[6a77224] | 99 | #define TICKET_BLOCKED (-1) // thread is blocked |
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| 100 | #define TICKET_RUNNING ( 0) // thread is running |
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| 101 | #define TICKET_UNBLOCK ( 1) // thread should ignore next block |
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| 102 | |
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[969b3fe] | 103 | //----------------------------------------------------------------------------- |
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| 104 | // Utils |
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[ac2b598] | 105 | void doregister( struct cluster * cltr, struct $thread & thrd ); |
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| 106 | void unregister( struct cluster * cltr, struct $thread & thrd ); |
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[de94a60] | 107 | |
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[f00b26d4] | 108 | //----------------------------------------------------------------------------- |
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| 109 | // I/O |
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[78da4ab] | 110 | $io_arbiter * create(void); |
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| 111 | void destroy($io_arbiter *); |
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[f00b26d4] | 112 | |
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[7768b8d] | 113 | //======================================================================= |
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| 114 | // Cluster lock API |
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| 115 | //======================================================================= |
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| 116 | // Lock-Free registering/unregistering of threads |
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| 117 | // Register a processor to a given cluster and get its unique id in return |
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[c993b15] | 118 | unsigned register_proc_id( void ); |
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[7768b8d] | 119 | |
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| 120 | // Unregister a processor from a given cluster using its id, getting back the original pointer |
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[c993b15] | 121 | void unregister_proc_id( unsigned ); |
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[7768b8d] | 122 | |
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| 123 | //======================================================================= |
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| 124 | // Reader-writer lock implementation |
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| 125 | // Concurrent with doregister/unregister, |
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| 126 | // i.e., threads can be added at any point during or between the entry/exit |
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[dca5802] | 127 | |
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| 128 | //----------------------------------------------------------------------- |
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| 129 | // simple spinlock underlying the RWLock |
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| 130 | // Blocking acquire |
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[7768b8d] | 131 | static inline void __atomic_acquire(volatile bool * ll) { |
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| 132 | while( __builtin_expect(__atomic_exchange_n(ll, (bool)true, __ATOMIC_SEQ_CST), false) ) { |
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| 133 | while(__atomic_load_n(ll, (int)__ATOMIC_RELAXED)) |
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[fd9b524] | 134 | Pause(); |
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[7768b8d] | 135 | } |
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| 136 | /* paranoid */ verify(*ll); |
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| 137 | } |
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| 138 | |
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[dca5802] | 139 | // Non-Blocking acquire |
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[7768b8d] | 140 | static inline bool __atomic_try_acquire(volatile bool * ll) { |
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[b798713] | 141 | return !__atomic_exchange_n(ll, (bool)true, __ATOMIC_SEQ_CST); |
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[7768b8d] | 142 | } |
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| 143 | |
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[dca5802] | 144 | // Release |
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[7768b8d] | 145 | static inline void __atomic_unlock(volatile bool * ll) { |
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| 146 | /* paranoid */ verify(*ll); |
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| 147 | __atomic_store_n(ll, (bool)false, __ATOMIC_RELEASE); |
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| 148 | } |
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| 149 | |
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[a33c113] | 150 | |
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| 151 | |
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| 152 | |
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| 153 | |
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[b388ee81] | 154 | //----------------------------------------------------------------------- |
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| 155 | // Reader-Writer lock protecting the ready-queues |
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| 156 | // while this lock is mostly generic some aspects |
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| 157 | // have been hard-coded to for the ready-queue for |
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| 158 | // simplicity and performance |
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| 159 | struct __scheduler_RWLock_t { |
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| 160 | // total cachelines allocated |
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| 161 | unsigned int max; |
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| 162 | |
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| 163 | // cachelines currently in use |
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| 164 | volatile unsigned int alloc; |
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| 165 | |
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| 166 | // cachelines ready to itereate over |
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| 167 | // (!= to alloc when thread is in second half of doregister) |
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| 168 | volatile unsigned int ready; |
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| 169 | |
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| 170 | // writer lock |
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[c993b15] | 171 | volatile bool write_lock; |
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[b388ee81] | 172 | |
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| 173 | // data pointer |
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[c993b15] | 174 | volatile bool * volatile * data; |
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[b388ee81] | 175 | }; |
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| 176 | |
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| 177 | void ?{}(__scheduler_RWLock_t & this); |
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| 178 | void ^?{}(__scheduler_RWLock_t & this); |
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| 179 | |
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| 180 | extern __scheduler_RWLock_t * __scheduler_lock; |
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| 181 | |
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[7768b8d] | 182 | //----------------------------------------------------------------------- |
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| 183 | // Reader side : acquire when using the ready queue to schedule but not |
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| 184 | // creating/destroying queues |
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[e873838] | 185 | static inline void ready_schedule_lock(void) with(*__scheduler_lock) { |
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[8fc652e0] | 186 | /* paranoid */ verify( ! __preemption_enabled() ); |
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[c993b15] | 187 | /* paranoid */ verify( ! kernelTLS().in_sched_lock ); |
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| 188 | /* paranoid */ verify( data[kernelTLS().sched_id] == &kernelTLS().sched_lock ); |
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| 189 | /* paranoid */ verify( !kernelTLS().this_processor || kernelTLS().this_processor->unique_id == kernelTLS().sched_id ); |
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[7768b8d] | 190 | |
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| 191 | // Step 1 : make sure no writer are in the middle of the critical section |
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[c993b15] | 192 | while(__atomic_load_n(&write_lock, (int)__ATOMIC_RELAXED)) |
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[fd9b524] | 193 | Pause(); |
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[7768b8d] | 194 | |
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| 195 | // Fence needed because we don't want to start trying to acquire the lock |
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| 196 | // before we read a false. |
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| 197 | // Not needed on x86 |
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| 198 | // std::atomic_thread_fence(std::memory_order_seq_cst); |
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| 199 | |
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| 200 | // Step 2 : acquire our local lock |
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[c993b15] | 201 | __atomic_acquire( &kernelTLS().sched_lock ); |
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| 202 | /*paranoid*/ verify(kernelTLS().sched_lock); |
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[64a7146] | 203 | |
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| 204 | #ifdef __CFA_WITH_VERIFY__ |
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| 205 | // Debug, check if this is owned for reading |
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[c993b15] | 206 | kernelTLS().in_sched_lock = true; |
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[64a7146] | 207 | #endif |
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[7768b8d] | 208 | } |
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| 209 | |
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[e873838] | 210 | static inline void ready_schedule_unlock(void) with(*__scheduler_lock) { |
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[8fc652e0] | 211 | /* paranoid */ verify( ! __preemption_enabled() ); |
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[c993b15] | 212 | /* paranoid */ verify( data[kernelTLS().sched_id] == &kernelTLS().sched_lock ); |
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| 213 | /* paranoid */ verify( !kernelTLS().this_processor || kernelTLS().this_processor->unique_id == kernelTLS().sched_id ); |
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| 214 | /* paranoid */ verify( kernelTLS().sched_lock ); |
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| 215 | /* paranoid */ verify( kernelTLS().in_sched_lock ); |
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[64a7146] | 216 | #ifdef __CFA_WITH_VERIFY__ |
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| 217 | // Debug, check if this is owned for reading |
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[c993b15] | 218 | kernelTLS().in_sched_lock = false; |
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[64a7146] | 219 | #endif |
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[c993b15] | 220 | __atomic_unlock(&kernelTLS().sched_lock); |
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[7768b8d] | 221 | } |
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| 222 | |
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[64a7146] | 223 | #ifdef __CFA_WITH_VERIFY__ |
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[e873838] | 224 | static inline bool ready_schedule_islocked(void) { |
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[8fc652e0] | 225 | /* paranoid */ verify( ! __preemption_enabled() ); |
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[c993b15] | 226 | /* paranoid */ verify( (!kernelTLS().in_sched_lock) || kernelTLS().sched_lock ); |
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| 227 | return kernelTLS().sched_lock; |
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[64a7146] | 228 | } |
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| 229 | |
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| 230 | static inline bool ready_mutate_islocked() { |
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[c993b15] | 231 | return __scheduler_lock->write_lock; |
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[64a7146] | 232 | } |
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| 233 | #endif |
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| 234 | |
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[7768b8d] | 235 | //----------------------------------------------------------------------- |
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| 236 | // Writer side : acquire when changing the ready queue, e.g. adding more |
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| 237 | // queues or removing them. |
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[b388ee81] | 238 | uint_fast32_t ready_mutate_lock( void ); |
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[7768b8d] | 239 | |
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[b388ee81] | 240 | void ready_mutate_unlock( uint_fast32_t /* value returned by lock */ ); |
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[7768b8d] | 241 | |
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[a33c113] | 242 | //----------------------------------------------------------------------- |
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| 243 | // Lock-Free registering/unregistering of threads |
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| 244 | // Register a processor to a given cluster and get its unique id in return |
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| 245 | // For convenience, also acquires the lock |
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[c993b15] | 246 | static inline [unsigned, uint_fast32_t] ready_mutate_register() { |
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| 247 | unsigned id = register_proc_id(); |
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| 248 | uint_fast32_t last = ready_mutate_lock(); |
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| 249 | return [id, last]; |
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[a33c113] | 250 | } |
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| 251 | |
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| 252 | // Unregister a processor from a given cluster using its id, getting back the original pointer |
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| 253 | // assumes the lock is acquired |
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[c993b15] | 254 | static inline void ready_mutate_unregister( unsigned id, uint_fast32_t last_s ) { |
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[a33c113] | 255 | ready_mutate_unlock( last_s ); |
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[c993b15] | 256 | unregister_proc_id( id ); |
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[a33c113] | 257 | } |
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| 258 | |
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[a7504db] | 259 | //----------------------------------------------------------------------- |
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| 260 | // Cluster idle lock/unlock |
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[6a9b12b] | 261 | static inline void lock(__cluster_proc_list & this) { |
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[a7504db] | 262 | /* paranoid */ verify( ! __preemption_enabled() ); |
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| 263 | |
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| 264 | // Start by locking the global RWlock so that we know no-one is |
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| 265 | // adding/removing processors while we mess with the idle lock |
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| 266 | ready_schedule_lock(); |
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| 267 | |
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| 268 | // Simple counting lock, acquired, acquired by incrementing the counter |
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| 269 | // to an odd number |
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| 270 | for() { |
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| 271 | uint64_t l = this.lock; |
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| 272 | if( |
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| 273 | (0 == (l % 2)) |
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| 274 | && __atomic_compare_exchange_n(&this.lock, &l, l + 1, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) |
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| 275 | ) return; |
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| 276 | Pause(); |
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| 277 | } |
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| 278 | |
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| 279 | /* paranoid */ verify( ! __preemption_enabled() ); |
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| 280 | } |
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| 281 | |
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[6a9b12b] | 282 | static inline void unlock(__cluster_proc_list & this) { |
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[a7504db] | 283 | /* paranoid */ verify( ! __preemption_enabled() ); |
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| 284 | |
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| 285 | /* paranoid */ verify( 1 == (this.lock % 2) ); |
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| 286 | // Simple couting lock, release by incrementing to an even number |
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| 287 | __atomic_fetch_add( &this.lock, 1, __ATOMIC_SEQ_CST ); |
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| 288 | |
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| 289 | // Release the global lock, which we acquired when locking |
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| 290 | ready_schedule_unlock(); |
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| 291 | |
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| 292 | /* paranoid */ verify( ! __preemption_enabled() ); |
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| 293 | } |
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| 294 | |
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[b798713] | 295 | //======================================================================= |
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| 296 | // Ready-Queue API |
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[dca5802] | 297 | //----------------------------------------------------------------------- |
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| 298 | // push thread onto a ready queue for a cluster |
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| 299 | // returns true if the list was previously empty, false otherwise |
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[b808625] | 300 | __attribute__((hot)) void push(struct cluster * cltr, struct $thread * thrd, bool local); |
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[dca5802] | 301 | |
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| 302 | //----------------------------------------------------------------------- |
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[fc59df78] | 303 | // pop thread from the local queues of a cluster |
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[dca5802] | 304 | // returns 0p if empty |
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[1eb239e4] | 305 | // May return 0p spuriously |
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[431cd4f] | 306 | __attribute__((hot)) struct $thread * pop_fast(struct cluster * cltr); |
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[dca5802] | 307 | |
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[1eb239e4] | 308 | //----------------------------------------------------------------------- |
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[fc59df78] | 309 | // pop thread from any ready queue of a cluster |
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[1eb239e4] | 310 | // returns 0p if empty |
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[fc59df78] | 311 | // May return 0p spuriously |
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[1eb239e4] | 312 | __attribute__((hot)) struct $thread * pop_slow(struct cluster * cltr); |
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| 313 | |
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[fc59df78] | 314 | //----------------------------------------------------------------------- |
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| 315 | // search all ready queues of a cluster for any thread |
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| 316 | // returns 0p if empty |
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| 317 | // guaranteed to find any threads added before this call |
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| 318 | __attribute__((hot)) struct $thread * pop_search(struct cluster * cltr); |
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| 319 | |
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[dca5802] | 320 | //----------------------------------------------------------------------- |
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| 321 | // Increase the width of the ready queue (number of lanes) by 4 |
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[a017ee7] | 322 | void ready_queue_grow (struct cluster * cltr); |
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[dca5802] | 323 | |
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| 324 | //----------------------------------------------------------------------- |
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| 325 | // Decrease the width of the ready queue (number of lanes) by 4 |
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[a017ee7] | 326 | void ready_queue_shrink(struct cluster * cltr); |
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[b798713] | 327 | |
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[de94a60] | 328 | |
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[75f3522] | 329 | // Local Variables: // |
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| 330 | // mode: c // |
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| 331 | // tab-width: 4 // |
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[4aa2fb2] | 332 | // End: // |
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