[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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[f558b5f] | 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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[059ad16] | 41 | // #define IO_URING_IDLE
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| 42 |
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[75f3522] | 43 | //-----------------------------------------------------------------------------
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| 44 | // Scheduler
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[1c273d0] | 45 | extern "C" {
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[2026bb6] | 46 | void disable_interrupts() OPTIONAL_THREAD;
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[a3821fa] | 47 | void enable_interrupts( bool poll = true );
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[1c273d0] | 48 | }
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| 49 |
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[24e321c] | 50 | void schedule_thread$( thread$ *, unpark_hint hint ) __attribute__((nonnull (1)));
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[75f3522] | 51 |
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[8fc652e0] | 52 | extern bool __preemption_enabled();
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| 53 |
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[5afb49a] | 54 | //release/wake-up the following resources
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[e84ab3d] | 55 | void __thread_finish( thread$ * thrd );
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[db6f06a] | 56 |
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[3489ea6] | 57 | //-----------------------------------------------------------------------------
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| 58 | // Hardware
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| 59 |
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| 60 | #if defined(CFA_HAVE_LINUX_LIBRSEQ)
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| 61 | // No data needed
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| 62 | #elif defined(CFA_HAVE_LINUX_RSEQ_H)
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| 63 | extern "Cforall" {
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[f558b5f] | 64 | extern __attribute__((aligned(128))) thread_local volatile struct rseq __cfaabi_rseq;
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[3489ea6] | 65 | }
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| 66 | #else
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| 67 | // No data needed
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| 68 | #endif
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| 69 |
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| 70 | static inline int __kernel_getcpu() {
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| 71 | /* paranoid */ verify( ! __preemption_enabled() );
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| 72 | #if defined(CFA_HAVE_LINUX_LIBRSEQ)
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[f558b5f] | 73 | return rseq_current_cpu();
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[3489ea6] | 74 | #elif defined(CFA_HAVE_LINUX_RSEQ_H)
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[f558b5f] | 75 | int r = __cfaabi_rseq.cpu_id;
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| 76 | /* paranoid */ verify( r >= 0 );
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| 77 | return r;
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[3489ea6] | 78 | #else
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| 79 | return sched_getcpu();
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| 80 | #endif
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| 81 | }
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| 82 |
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[75f3522] | 83 | //-----------------------------------------------------------------------------
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| 84 | // Processor
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| 85 | void main(processorCtx_t *);
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[85b1deb] | 86 |
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[8c50aed] | 87 | void * __create_pthread( pthread_t *, void * (*)(void *), void * );
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[bfcf6b9] | 88 | void __destroy_pthread( pthread_t pthread, void * stack, void ** retval );
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[1805b1b] | 89 |
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[6502a2b] | 90 | extern cluster * mainCluster;
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| 91 |
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[75f3522] | 92 | //-----------------------------------------------------------------------------
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| 93 | // Threads
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| 94 | extern "C" {
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[c7a900a] | 95 | void __cfactx_invoke_thread(void (*main)(void *), void * this);
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[75f3522] | 96 | }
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| 97 |
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[f7d6bb0] | 98 | __cfaabi_dbg_debug_do(
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[e84ab3d] | 99 | extern void __cfaabi_dbg_thread_register ( thread$ * thrd );
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| 100 | extern void __cfaabi_dbg_thread_unregister( thread$ * thrd );
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[f7d6bb0] | 101 | )
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| 102 |
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[6a77224] | 103 | #define TICKET_BLOCKED (-1) // thread is blocked
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| 104 | #define TICKET_RUNNING ( 0) // thread is running
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| 105 | #define TICKET_UNBLOCK ( 1) // thread should ignore next block
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| 106 |
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[969b3fe] | 107 | //-----------------------------------------------------------------------------
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| 108 | // Utils
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[e84ab3d] | 109 | void doregister( struct cluster * cltr, struct thread$ & thrd );
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| 110 | void unregister( struct cluster * cltr, struct thread$ & thrd );
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[de94a60] | 111 |
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[f00b26d4] | 112 | //-----------------------------------------------------------------------------
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| 113 | // I/O
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[78da4ab] | 114 | $io_arbiter * create(void);
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| 115 | void destroy($io_arbiter *);
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[f00b26d4] | 116 |
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[7768b8d] | 117 | //=======================================================================
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| 118 | // Cluster lock API
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| 119 | //=======================================================================
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| 120 | // Lock-Free registering/unregistering of threads
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| 121 | // Register a processor to a given cluster and get its unique id in return
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[c993b15] | 122 | unsigned register_proc_id( void );
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[7768b8d] | 123 |
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| 124 | // Unregister a processor from a given cluster using its id, getting back the original pointer
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[c993b15] | 125 | void unregister_proc_id( unsigned );
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[7768b8d] | 126 |
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| 127 | //=======================================================================
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| 128 | // Reader-writer lock implementation
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| 129 | // Concurrent with doregister/unregister,
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| 130 | // i.e., threads can be added at any point during or between the entry/exit
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[dca5802] | 131 |
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| 132 | //-----------------------------------------------------------------------
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| 133 | // simple spinlock underlying the RWLock
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| 134 | // Blocking acquire
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[7768b8d] | 135 | static inline void __atomic_acquire(volatile bool * ll) {
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| 136 | while( __builtin_expect(__atomic_exchange_n(ll, (bool)true, __ATOMIC_SEQ_CST), false) ) {
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| 137 | while(__atomic_load_n(ll, (int)__ATOMIC_RELAXED))
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[fd9b524] | 138 | Pause();
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[7768b8d] | 139 | }
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| 140 | /* paranoid */ verify(*ll);
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| 141 | }
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| 142 |
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[dca5802] | 143 | // Non-Blocking acquire
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[7768b8d] | 144 | static inline bool __atomic_try_acquire(volatile bool * ll) {
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[b798713] | 145 | return !__atomic_exchange_n(ll, (bool)true, __ATOMIC_SEQ_CST);
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[7768b8d] | 146 | }
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| 147 |
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[dca5802] | 148 | // Release
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[7768b8d] | 149 | static inline void __atomic_unlock(volatile bool * ll) {
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| 150 | /* paranoid */ verify(*ll);
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| 151 | __atomic_store_n(ll, (bool)false, __ATOMIC_RELEASE);
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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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[a7504db5] | 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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[a7504db5] | 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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[a633f6f] | 268 | lock( this.lock __cfaabi_dbg_ctx2 );
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[a7504db5] | 269 |
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| 270 | /* paranoid */ verify( ! __preemption_enabled() );
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| 271 | }
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| 272 |
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[5f5a729] | 273 | static inline bool try_lock(__cluster_proc_list & this) {
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| 274 | /* paranoid */ verify( ! __preemption_enabled() );
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| 275 |
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| 276 | // Start by locking the global RWlock so that we know no-one is
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| 277 | // adding/removing processors while we mess with the idle lock
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| 278 | ready_schedule_lock();
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| 279 |
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[a633f6f] | 280 | if(try_lock( this.lock __cfaabi_dbg_ctx2 )) {
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[5f5a729] | 281 | // success
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| 282 | /* paranoid */ verify( ! __preemption_enabled() );
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| 283 | return true;
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| 284 | }
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| 285 |
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| 286 | // failed to lock
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| 287 | ready_schedule_unlock();
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| 288 |
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| 289 | /* paranoid */ verify( ! __preemption_enabled() );
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| 290 | return false;
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| 291 | }
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| 292 |
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[6a9b12b] | 293 | static inline void unlock(__cluster_proc_list & this) {
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[a7504db5] | 294 | /* paranoid */ verify( ! __preemption_enabled() );
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| 295 |
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[a633f6f] | 296 | unlock(this.lock);
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[a7504db5] | 297 |
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| 298 | // Release the global lock, which we acquired when locking
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| 299 | ready_schedule_unlock();
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| 300 |
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| 301 | /* paranoid */ verify( ! __preemption_enabled() );
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| 302 | }
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| 303 |
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[b798713] | 304 | //=======================================================================
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| 305 | // Ready-Queue API
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[dca5802] | 306 | //-----------------------------------------------------------------------
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| 307 | // push thread onto a ready queue for a cluster
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| 308 | // returns true if the list was previously empty, false otherwise
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[24e321c] | 309 | __attribute__((hot)) void push(struct cluster * cltr, struct thread$ * thrd, unpark_hint hint);
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[dca5802] | 310 |
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| 311 | //-----------------------------------------------------------------------
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[fc59df78] | 312 | // pop thread from the local queues of a cluster
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[dca5802] | 313 | // returns 0p if empty
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[1eb239e4] | 314 | // May return 0p spuriously
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[e84ab3d] | 315 | __attribute__((hot)) struct thread$ * pop_fast(struct cluster * cltr);
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[dca5802] | 316 |
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[1eb239e4] | 317 | //-----------------------------------------------------------------------
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[fc59df78] | 318 | // pop thread from any ready queue of a cluster
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[1eb239e4] | 319 | // returns 0p if empty
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[fc59df78] | 320 | // May return 0p spuriously
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[e84ab3d] | 321 | __attribute__((hot)) struct thread$ * pop_slow(struct cluster * cltr);
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[1eb239e4] | 322 |
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[fc59df78] | 323 | //-----------------------------------------------------------------------
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| 324 | // search all ready queues of a cluster for any thread
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| 325 | // returns 0p if empty
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| 326 | // guaranteed to find any threads added before this call
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[e84ab3d] | 327 | __attribute__((hot)) struct thread$ * pop_search(struct cluster * cltr);
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[fc59df78] | 328 |
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[24e321c] | 329 | //-----------------------------------------------------------------------
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| 330 | // get preferred ready for new thread
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| 331 | unsigned ready_queue_new_preferred();
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| 332 |
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[dca5802] | 333 | //-----------------------------------------------------------------------
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| 334 | // Increase the width of the ready queue (number of lanes) by 4
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[a017ee7] | 335 | void ready_queue_grow (struct cluster * cltr);
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[dca5802] | 336 |
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| 337 | //-----------------------------------------------------------------------
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| 338 | // Decrease the width of the ready queue (number of lanes) by 4
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[a017ee7] | 339 | void ready_queue_shrink(struct cluster * cltr);
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[b798713] | 340 |
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[de94a60] | 341 |
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[75f3522] | 342 | // Local Variables: //
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| 343 | // mode: c //
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| 344 | // tab-width: 4 //
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[4aa2fb2] | 345 | // End: //
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