source: libcfa/src/concurrency/io/setup.cfa@ ec43cf9

ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since ec43cf9 was 11054eb, checked in by Thierry Delisle <tdelisle@…>, 4 years ago

Fix io to no longer use monitors since some usages aren't in threads

  • Property mode set to 100644
File size: 11.9 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2020 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// io/setup.cfa --
8//
9// Author : Thierry Delisle
10// Created On : Fri Jul 31 16:25:51 2020
11// Last Modified By :
12// Last Modified On :
13// Update Count :
14//
15
16#define __cforall_thread__
17#define _GNU_SOURCE /* See feature_test_macros(7) */
18
19#if defined(__CFA_DEBUG__)
20 // #define __CFA_DEBUG_PRINT_IO__
21 // #define __CFA_DEBUG_PRINT_IO_CORE__
22#endif
23
24#include "io/types.hfa"
25#include "kernel.hfa"
26
27#if !defined(CFA_HAVE_LINUX_IO_URING_H)
28 void ?{}(io_context_params & this) {}
29
30 void ?{}($io_context & this, struct cluster & cl) {}
31 void ^?{}($io_context & this) {}
32
33 void __cfa_io_start( processor * proc ) {}
34 void __cfa_io_flush( processor * proc ) {}
35 void __cfa_io_stop ( processor * proc ) {}
36
37 $io_arbiter * create(void) { return 0p; }
38 void destroy($io_arbiter *) {}
39
40#else
41 #include <errno.h>
42 #include <stdint.h>
43 #include <string.h>
44 #include <signal.h>
45 #include <unistd.h>
46
47 extern "C" {
48 #include <pthread.h>
49 #include <sys/epoll.h>
50 #include <sys/eventfd.h>
51 #include <sys/mman.h>
52 #include <sys/syscall.h>
53
54 #include <linux/io_uring.h>
55 }
56
57 #include "bitmanip.hfa"
58 #include "kernel_private.hfa"
59 #include "thread.hfa"
60
61 void ?{}(io_context_params & this) {
62 this.num_entries = 256;
63 }
64
65 static void * __io_poller_slow( void * arg );
66
67 // Weirdly, some systems that do support io_uring don't actually define these
68 #ifdef __alpha__
69 /*
70 * alpha is the only exception, all other architectures
71 * have common numbers for new system calls.
72 */
73 #ifndef __NR_io_uring_setup
74 #define __NR_io_uring_setup 535
75 #endif
76 #ifndef __NR_io_uring_enter
77 #define __NR_io_uring_enter 536
78 #endif
79 #ifndef __NR_io_uring_register
80 #define __NR_io_uring_register 537
81 #endif
82 #else /* !__alpha__ */
83 #ifndef __NR_io_uring_setup
84 #define __NR_io_uring_setup 425
85 #endif
86 #ifndef __NR_io_uring_enter
87 #define __NR_io_uring_enter 426
88 #endif
89 #ifndef __NR_io_uring_register
90 #define __NR_io_uring_register 427
91 #endif
92 #endif
93
94//=============================================================================================
95// I/O Context Constrution/Destruction
96//=============================================================================================
97
98
99
100 static void __io_uring_setup ( $io_context & this, const io_context_params & params_in, int procfd );
101 static void __io_uring_teardown( $io_context & this );
102 static void __epoll_register($io_context & ctx);
103 static void __epoll_unregister($io_context & ctx);
104 void __ioarbiter_register( $io_arbiter & mutex, $io_context & ctx );
105 void __ioarbiter_unregister( $io_arbiter & mutex, $io_context & ctx );
106
107 void ?{}($io_context & this, processor * proc, struct cluster & cl) {
108 /* paranoid */ verify( cl.io.arbiter );
109 this.proc = proc;
110 this.arbiter = cl.io.arbiter;
111 this.ext_sq.empty = true;
112 (this.ext_sq.queue){};
113 __io_uring_setup( this, cl.io.params, proc->idle );
114 __cfadbg_print_safe(io_core, "Kernel I/O : Created ring for io_context %u (%p)\n", this.fd, &this);
115 }
116
117 void ^?{}($io_context & this) {
118 __cfadbg_print_safe(io_core, "Kernel I/O : tearing down io_context %u\n", this.fd);
119
120 __io_uring_teardown( this );
121 __cfadbg_print_safe(io_core, "Kernel I/O : Destroyed ring for io_context %u\n", this.fd);
122 }
123
124 extern void __disable_interrupts_hard();
125 extern void __enable_interrupts_hard();
126
127 static void __io_uring_setup( $io_context & this, const io_context_params & params_in, int procfd ) {
128 // Step 1 : call to setup
129 struct io_uring_params params;
130 memset(&params, 0, sizeof(params));
131 // if( params_in.poll_submit ) params.flags |= IORING_SETUP_SQPOLL;
132 // if( params_in.poll_complete ) params.flags |= IORING_SETUP_IOPOLL;
133
134 __u32 nentries = params_in.num_entries != 0 ? params_in.num_entries : 256;
135 if( !is_pow2(nentries) ) {
136 abort("ERROR: I/O setup 'num_entries' must be a power of 2\n");
137 }
138
139 int fd = syscall(__NR_io_uring_setup, nentries, &params );
140 if(fd < 0) {
141 abort("KERNEL ERROR: IO_URING SETUP - %s\n", strerror(errno));
142 }
143
144 // Step 2 : mmap result
145 struct __sub_ring_t & sq = this.sq;
146 struct __cmp_ring_t & cq = this.cq;
147
148 // calculate the right ring size
149 sq.ring_sz = params.sq_off.array + (params.sq_entries * sizeof(unsigned) );
150 cq.ring_sz = params.cq_off.cqes + (params.cq_entries * sizeof(struct io_uring_cqe));
151
152 // Requires features
153 #if defined(IORING_FEAT_SINGLE_MMAP)
154 // adjust the size according to the parameters
155 if ((params.features & IORING_FEAT_SINGLE_MMAP) != 0) {
156 cq.ring_sz = sq.ring_sz = max(cq.ring_sz, sq.ring_sz);
157 }
158 #endif
159
160 // mmap the Submit Queue into existence
161 sq.ring_ptr = mmap(0, sq.ring_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_SQ_RING);
162 if (sq.ring_ptr == (void*)MAP_FAILED) {
163 abort("KERNEL ERROR: IO_URING MMAP1 - %s\n", strerror(errno));
164 }
165
166 // Requires features
167 #if defined(IORING_FEAT_SINGLE_MMAP)
168 // mmap the Completion Queue into existence (may or may not be needed)
169 if ((params.features & IORING_FEAT_SINGLE_MMAP) != 0) {
170 cq.ring_ptr = sq.ring_ptr;
171 }
172 else
173 #endif
174 {
175 // We need multiple call to MMAP
176 cq.ring_ptr = mmap(0, cq.ring_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_CQ_RING);
177 if (cq.ring_ptr == (void*)MAP_FAILED) {
178 munmap(sq.ring_ptr, sq.ring_sz);
179 abort("KERNEL ERROR: IO_URING MMAP2 - %s\n", strerror(errno));
180 }
181 }
182
183 // mmap the submit queue entries
184 size_t size = params.sq_entries * sizeof(struct io_uring_sqe);
185 sq.sqes = (struct io_uring_sqe *)mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_SQES);
186 if (sq.sqes == (struct io_uring_sqe *)MAP_FAILED) {
187 munmap(sq.ring_ptr, sq.ring_sz);
188 if (cq.ring_ptr != sq.ring_ptr) munmap(cq.ring_ptr, cq.ring_sz);
189 abort("KERNEL ERROR: IO_URING MMAP3 - %s\n", strerror(errno));
190 }
191
192 // Step 3 : Initialize the data structure
193 // Get the pointers from the kernel to fill the structure
194 // submit queue
195 sq.kring.head = (volatile __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.head);
196 sq.kring.tail = (volatile __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.tail);
197 sq.kring.array = ( __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.array);
198 sq.mask = ( const __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.ring_mask);
199 sq.num = ( const __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.ring_entries);
200 sq.flags = ( __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.flags);
201 sq.dropped = ( __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.dropped);
202
203 sq.kring.released = 0;
204
205 sq.free_ring.head = 0;
206 sq.free_ring.tail = *sq.num;
207 sq.free_ring.array = alloc( *sq.num, 128`align );
208 for(i; (__u32)*sq.num) {
209 sq.free_ring.array[i] = i;
210 }
211
212 sq.to_submit = 0;
213
214 // completion queue
215 cq.head = (volatile __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.head);
216 cq.tail = (volatile __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.tail);
217 cq.mask = ( const __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.ring_mask);
218 cq.num = ( const __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.ring_entries);
219 cq.overflow = ( __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.overflow);
220 cq.cqes = (struct io_uring_cqe *)(((intptr_t)cq.ring_ptr) + params.cq_off.cqes);
221
222 // Step 4 : eventfd
223 // io_uring_register is so f*cking slow on some machine that it
224 // will never succeed if preemption isn't hard blocked
225 __cfadbg_print_safe(io_core, "Kernel I/O : registering %d for completion with ring %d\n", procfd, fd);
226
227 __disable_interrupts_hard();
228
229 int ret = syscall( __NR_io_uring_register, fd, IORING_REGISTER_EVENTFD, &procfd, 1);
230 if (ret < 0) {
231 abort("KERNEL ERROR: IO_URING EVENTFD REGISTER - %s\n", strerror(errno));
232 }
233
234 __enable_interrupts_hard();
235
236 __cfadbg_print_safe(io_core, "Kernel I/O : registered %d for completion with ring %d\n", procfd, fd);
237
238 // some paranoid checks
239 /* paranoid */ verifyf( (*cq.mask) == ((*cq.num) - 1ul32), "IO_URING Expected mask to be %u (%u entries), was %u", (*cq.num) - 1ul32, *cq.num, *cq.mask );
240 /* paranoid */ verifyf( (*cq.num) >= nentries, "IO_URING Expected %u entries, got %u", nentries, *cq.num );
241 /* paranoid */ verifyf( (*cq.head) == 0, "IO_URING Expected head to be 0, got %u", *cq.head );
242 /* paranoid */ verifyf( (*cq.tail) == 0, "IO_URING Expected tail to be 0, got %u", *cq.tail );
243
244 /* paranoid */ verifyf( (*sq.mask) == ((*sq.num) - 1ul32), "IO_URING Expected mask to be %u (%u entries), was %u", (*sq.num) - 1ul32, *sq.num, *sq.mask );
245 /* paranoid */ verifyf( (*sq.num) >= nentries, "IO_URING Expected %u entries, got %u", nentries, *sq.num );
246 /* paranoid */ verifyf( (*sq.kring.head) == 0, "IO_URING Expected head to be 0, got %u", *sq.kring.head );
247 /* paranoid */ verifyf( (*sq.kring.tail) == 0, "IO_URING Expected tail to be 0, got %u", *sq.kring.tail );
248
249 // Update the global ring info
250 this.ring_flags = 0;
251 this.fd = fd;
252 }
253
254 static void __io_uring_teardown( $io_context & this ) {
255 // Shutdown the io rings
256 struct __sub_ring_t & sq = this.sq;
257 struct __cmp_ring_t & cq = this.cq;
258
259 // unmap the submit queue entries
260 munmap(sq.sqes, (*sq.num) * sizeof(struct io_uring_sqe));
261
262 // unmap the Submit Queue ring
263 munmap(sq.ring_ptr, sq.ring_sz);
264
265 // unmap the Completion Queue ring, if it is different
266 if (cq.ring_ptr != sq.ring_ptr) {
267 munmap(cq.ring_ptr, cq.ring_sz);
268 }
269
270 // close the file descriptor
271 close(this.fd);
272
273 free( this.sq.free_ring.array ); // Maybe null, doesn't matter
274 }
275
276 void __cfa_io_start( processor * proc ) {
277 proc->io.ctx = alloc();
278 (*proc->io.ctx){proc, *proc->cltr};
279 }
280 void __cfa_io_stop ( processor * proc ) {
281 ^(*proc->io.ctx){};
282 free(proc->io.ctx);
283 }
284
285//=============================================================================================
286// I/O Context Sleep
287//=============================================================================================
288 // static inline void __epoll_ctl($io_context & ctx, int op, const char * error) {
289 // struct epoll_event ev;
290 // ev.events = EPOLLIN | EPOLLONESHOT;
291 // ev.data.u64 = (__u64)&ctx;
292 // int ret = epoll_ctl(iopoll.epollfd, op, ctx.efd, &ev);
293 // if (ret < 0) {
294 // abort( "KERNEL ERROR: EPOLL %s - (%d) %s\n", error, (int)errno, strerror(errno) );
295 // }
296 // }
297
298 // static void __epoll_register($io_context & ctx) {
299 // __epoll_ctl(ctx, EPOLL_CTL_ADD, "ADD");
300 // }
301
302 // static void __epoll_unregister($io_context & ctx) {
303 // // Read the current epoch so we know when to stop
304 // size_t curr = __atomic_load_n(&iopoll.epoch, __ATOMIC_SEQ_CST);
305
306 // // Remove the fd from the iopoller
307 // __epoll_ctl(ctx, EPOLL_CTL_DEL, "REMOVE");
308
309 // // Notify the io poller thread of the shutdown
310 // iopoll.run = false;
311 // sigval val = { 1 };
312 // pthread_sigqueue( iopoll.thrd, SIGUSR1, val );
313
314 // // Make sure all this is done
315 // __atomic_thread_fence(__ATOMIC_SEQ_CST);
316
317 // // Wait for the next epoch
318 // while(curr == iopoll.epoch && !iopoll.stopped) Pause();
319 // }
320
321 // void __ioctx_prepare_block($io_context & ctx) {
322 // __cfadbg_print_safe(io_core, "Kernel I/O - epoll : Re-arming io poller %d (%p)\n", ctx.fd, &ctx);
323 // __epoll_ctl(ctx, EPOLL_CTL_MOD, "REARM");
324 // }
325
326
327//=============================================================================================
328// I/O Context Misc Setup
329//=============================================================================================
330 void ?{}( $io_arbiter & this ) {
331 this.pending.empty = true;
332 }
333
334 void ^?{}( $io_arbiter & this ) {}
335
336 $io_arbiter * create(void) {
337 return new();
338 }
339 void destroy($io_arbiter * arbiter) {
340 delete(arbiter);
341 }
342
343//=============================================================================================
344// I/O Context Misc Setup
345//=============================================================================================
346
347#endif
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