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.cfa -- |
---|
8 | // |
---|
9 | // Author : Thierry Delisle |
---|
10 | // Created On : Thu Apr 23 17:31:00 2020 |
---|
11 | // Last Modified By : |
---|
12 | // Last Modified On : |
---|
13 | // Update Count : |
---|
14 | // |
---|
15 | |
---|
16 | #define __cforall_thread__ |
---|
17 | #define _GNU_SOURCE |
---|
18 | |
---|
19 | #if defined(__CFA_DEBUG__) |
---|
20 | // #define __CFA_DEBUG_PRINT_IO__ |
---|
21 | // #define __CFA_DEBUG_PRINT_IO_CORE__ |
---|
22 | #endif |
---|
23 | |
---|
24 | |
---|
25 | #if defined(CFA_HAVE_LINUX_IO_URING_H) |
---|
26 | #include <errno.h> |
---|
27 | #include <signal.h> |
---|
28 | #include <stdint.h> |
---|
29 | #include <string.h> |
---|
30 | #include <unistd.h> |
---|
31 | |
---|
32 | extern "C" { |
---|
33 | #include <sys/syscall.h> |
---|
34 | #include <sys/eventfd.h> |
---|
35 | #include <sys/uio.h> |
---|
36 | |
---|
37 | #include <linux/io_uring.h> |
---|
38 | } |
---|
39 | |
---|
40 | #include "stats.hfa" |
---|
41 | #include "kernel.hfa" |
---|
42 | #include "kernel/fwd.hfa" |
---|
43 | #include "kernel_private.hfa" |
---|
44 | #include "io/types.hfa" |
---|
45 | |
---|
46 | __attribute__((unused)) static const char * opcodes[] = { |
---|
47 | "OP_NOP", |
---|
48 | "OP_READV", |
---|
49 | "OP_WRITEV", |
---|
50 | "OP_FSYNC", |
---|
51 | "OP_READ_FIXED", |
---|
52 | "OP_WRITE_FIXED", |
---|
53 | "OP_POLL_ADD", |
---|
54 | "OP_POLL_REMOVE", |
---|
55 | "OP_SYNC_FILE_RANGE", |
---|
56 | "OP_SENDMSG", |
---|
57 | "OP_RECVMSG", |
---|
58 | "OP_TIMEOUT", |
---|
59 | "OP_TIMEOUT_REMOVE", |
---|
60 | "OP_ACCEPT", |
---|
61 | "OP_ASYNC_CANCEL", |
---|
62 | "OP_LINK_TIMEOUT", |
---|
63 | "OP_CONNECT", |
---|
64 | "OP_FALLOCATE", |
---|
65 | "OP_OPENAT", |
---|
66 | "OP_CLOSE", |
---|
67 | "OP_FILES_UPDATE", |
---|
68 | "OP_STATX", |
---|
69 | "OP_READ", |
---|
70 | "OP_WRITE", |
---|
71 | "OP_FADVISE", |
---|
72 | "OP_MADVISE", |
---|
73 | "OP_SEND", |
---|
74 | "OP_RECV", |
---|
75 | "OP_OPENAT2", |
---|
76 | "OP_EPOLL_CTL", |
---|
77 | "OP_SPLICE", |
---|
78 | "OP_PROVIDE_BUFFERS", |
---|
79 | "OP_REMOVE_BUFFERS", |
---|
80 | "OP_TEE", |
---|
81 | "INVALID_OP" |
---|
82 | }; |
---|
83 | |
---|
84 | static $io_context * __ioarbiter_allocate( $io_arbiter & this, __u32 idxs[], __u32 want ); |
---|
85 | static void __ioarbiter_submit( $io_context * , __u32 idxs[], __u32 have, bool lazy ); |
---|
86 | static void __ioarbiter_flush ( $io_context & ); |
---|
87 | static inline void __ioarbiter_notify( $io_context & ctx ); |
---|
88 | //============================================================================================= |
---|
89 | // I/O Polling |
---|
90 | //============================================================================================= |
---|
91 | static inline unsigned __flush( struct $io_context & ); |
---|
92 | static inline __u32 __release_sqes( struct $io_context & ); |
---|
93 | extern void __kernel_unpark( thread$ * thrd, unpark_hint ); |
---|
94 | |
---|
95 | bool __cfa_io_drain( processor * proc ) { |
---|
96 | /* paranoid */ verify( ! __preemption_enabled() ); |
---|
97 | /* paranoid */ verify( ready_schedule_islocked() ); |
---|
98 | /* paranoid */ verify( proc ); |
---|
99 | /* paranoid */ verify( proc->io.ctx ); |
---|
100 | |
---|
101 | // Drain the queue |
---|
102 | $io_context * ctx = proc->io.ctx; |
---|
103 | unsigned head = *ctx->cq.head; |
---|
104 | unsigned tail = *ctx->cq.tail; |
---|
105 | const __u32 mask = *ctx->cq.mask; |
---|
106 | |
---|
107 | __u32 count = tail - head; |
---|
108 | __STATS__( false, io.calls.drain++; io.calls.completed += count; ) |
---|
109 | |
---|
110 | if(count == 0) return false; |
---|
111 | |
---|
112 | for(i; count) { |
---|
113 | unsigned idx = (head + i) & mask; |
---|
114 | volatile struct io_uring_cqe & cqe = ctx->cq.cqes[idx]; |
---|
115 | |
---|
116 | /* paranoid */ verify(&cqe); |
---|
117 | |
---|
118 | struct io_future_t * future = (struct io_future_t *)(uintptr_t)cqe.user_data; |
---|
119 | __cfadbg_print_safe( io, "Kernel I/O : Syscall completed : cqe %p, result %d for %p\n", &cqe, cqe.res, future ); |
---|
120 | |
---|
121 | __kernel_unpark( fulfil( *future, cqe.res, false ), UNPARK_LOCAL ); |
---|
122 | } |
---|
123 | |
---|
124 | __cfadbg_print_safe(io, "Kernel I/O : %u completed\n", count); |
---|
125 | |
---|
126 | // Mark to the kernel that the cqe has been seen |
---|
127 | // Ensure that the kernel only sees the new value of the head index after the CQEs have been read. |
---|
128 | __atomic_store_n( ctx->cq.head, head + count, __ATOMIC_SEQ_CST ); |
---|
129 | |
---|
130 | /* paranoid */ verify( ready_schedule_islocked() ); |
---|
131 | /* paranoid */ verify( ! __preemption_enabled() ); |
---|
132 | |
---|
133 | return true; |
---|
134 | } |
---|
135 | |
---|
136 | bool __cfa_io_flush( processor * proc, int min_comp ) { |
---|
137 | /* paranoid */ verify( ! __preemption_enabled() ); |
---|
138 | /* paranoid */ verify( proc ); |
---|
139 | /* paranoid */ verify( proc->io.ctx ); |
---|
140 | |
---|
141 | __attribute__((unused)) cluster * cltr = proc->cltr; |
---|
142 | $io_context & ctx = *proc->io.ctx; |
---|
143 | |
---|
144 | __ioarbiter_flush( ctx ); |
---|
145 | |
---|
146 | if(ctx.sq.to_submit != 0 || min_comp > 0) { |
---|
147 | |
---|
148 | __STATS__( true, io.calls.flush++; ) |
---|
149 | int ret = syscall( __NR_io_uring_enter, ctx.fd, ctx.sq.to_submit, min_comp, min_comp > 0 ? IORING_ENTER_GETEVENTS : 0, (sigset_t *)0p, _NSIG / 8); |
---|
150 | if( ret < 0 ) { |
---|
151 | switch((int)errno) { |
---|
152 | case EAGAIN: |
---|
153 | case EINTR: |
---|
154 | case EBUSY: |
---|
155 | // Update statistics |
---|
156 | __STATS__( false, io.calls.errors.busy ++; ) |
---|
157 | return false; |
---|
158 | default: |
---|
159 | abort( "KERNEL ERROR: IO_URING SYSCALL - (%d) %s\n", (int)errno, strerror(errno) ); |
---|
160 | } |
---|
161 | } |
---|
162 | |
---|
163 | __cfadbg_print_safe(io, "Kernel I/O : %u submitted to io_uring %d\n", ret, ctx.fd); |
---|
164 | __STATS__( true, io.calls.submitted += ret; ) |
---|
165 | /* paranoid */ verify( ctx.sq.to_submit <= *ctx.sq.num ); |
---|
166 | /* paranoid */ verify( ctx.sq.to_submit >= ret ); |
---|
167 | |
---|
168 | ctx.sq.to_submit -= ret; |
---|
169 | |
---|
170 | /* paranoid */ verify( ctx.sq.to_submit <= *ctx.sq.num ); |
---|
171 | |
---|
172 | // Release the consumed SQEs |
---|
173 | __release_sqes( ctx ); |
---|
174 | |
---|
175 | /* paranoid */ verify( ! __preemption_enabled() ); |
---|
176 | |
---|
177 | ctx.proc->io.pending = false; |
---|
178 | } |
---|
179 | |
---|
180 | ready_schedule_lock(); |
---|
181 | bool ret = __cfa_io_drain( proc ); |
---|
182 | ready_schedule_unlock(); |
---|
183 | return ret; |
---|
184 | } |
---|
185 | |
---|
186 | //============================================================================================= |
---|
187 | // I/O Submissions |
---|
188 | //============================================================================================= |
---|
189 | |
---|
190 | // Submition steps : |
---|
191 | // 1 - Allocate a queue entry. The ring already has memory for all entries but only the ones |
---|
192 | // listed in sq.array are visible by the kernel. For those not listed, the kernel does not |
---|
193 | // offer any assurance that an entry is not being filled by multiple flags. Therefore, we |
---|
194 | // need to write an allocator that allows allocating concurrently. |
---|
195 | // |
---|
196 | // 2 - Actually fill the submit entry, this is the only simple and straightforward step. |
---|
197 | // |
---|
198 | // 3 - Append the entry index to the array and adjust the tail accordingly. This operation |
---|
199 | // needs to arrive to two concensus at the same time: |
---|
200 | // A - The order in which entries are listed in the array: no two threads must pick the |
---|
201 | // same index for their entries |
---|
202 | // B - When can the tail be update for the kernel. EVERY entries in the array between |
---|
203 | // head and tail must be fully filled and shouldn't ever be touched again. |
---|
204 | // |
---|
205 | //============================================================================================= |
---|
206 | // Allocation |
---|
207 | // for user's convenience fill the sqes from the indexes |
---|
208 | static inline void __fill(struct io_uring_sqe * out_sqes[], __u32 want, __u32 idxs[], struct $io_context * ctx) { |
---|
209 | struct io_uring_sqe * sqes = ctx->sq.sqes; |
---|
210 | for(i; want) { |
---|
211 | __cfadbg_print_safe(io, "Kernel I/O : filling loop\n"); |
---|
212 | out_sqes[i] = &sqes[idxs[i]]; |
---|
213 | } |
---|
214 | } |
---|
215 | |
---|
216 | // Try to directly allocate from the a given context |
---|
217 | // Not thread-safe |
---|
218 | static inline bool __alloc(struct $io_context * ctx, __u32 idxs[], __u32 want) { |
---|
219 | __sub_ring_t & sq = ctx->sq; |
---|
220 | const __u32 mask = *sq.mask; |
---|
221 | __u32 fhead = sq.free_ring.head; // get the current head of the queue |
---|
222 | __u32 ftail = sq.free_ring.tail; // get the current tail of the queue |
---|
223 | |
---|
224 | // If we don't have enough sqes, fail |
---|
225 | if((ftail - fhead) < want) { return false; } |
---|
226 | |
---|
227 | // copy all the indexes we want from the available list |
---|
228 | for(i; want) { |
---|
229 | __cfadbg_print_safe(io, "Kernel I/O : allocating loop\n"); |
---|
230 | idxs[i] = sq.free_ring.array[(fhead + i) & mask]; |
---|
231 | } |
---|
232 | |
---|
233 | // Advance the head to mark the indexes as consumed |
---|
234 | __atomic_store_n(&sq.free_ring.head, fhead + want, __ATOMIC_RELEASE); |
---|
235 | |
---|
236 | // return success |
---|
237 | return true; |
---|
238 | } |
---|
239 | |
---|
240 | // Allocate an submit queue entry. |
---|
241 | // The kernel cannot see these entries until they are submitted, but other threads must be |
---|
242 | // able to see which entries can be used and which are already un used by an other thread |
---|
243 | // for convenience, return both the index and the pointer to the sqe |
---|
244 | // sqe == &sqes[idx] |
---|
245 | struct $io_context * cfa_io_allocate(struct io_uring_sqe * sqes[], __u32 idxs[], __u32 want) { |
---|
246 | __cfadbg_print_safe(io, "Kernel I/O : attempting to allocate %u\n", want); |
---|
247 | |
---|
248 | disable_interrupts(); |
---|
249 | processor * proc = __cfaabi_tls.this_processor; |
---|
250 | $io_context * ctx = proc->io.ctx; |
---|
251 | /* paranoid */ verify( __cfaabi_tls.this_processor ); |
---|
252 | /* paranoid */ verify( ctx ); |
---|
253 | |
---|
254 | __cfadbg_print_safe(io, "Kernel I/O : attempting to fast allocation\n"); |
---|
255 | |
---|
256 | // We can proceed to the fast path |
---|
257 | if( __alloc(ctx, idxs, want) ) { |
---|
258 | // Allocation was successful |
---|
259 | __STATS__( true, io.alloc.fast += 1; ) |
---|
260 | enable_interrupts(); |
---|
261 | |
---|
262 | __cfadbg_print_safe(io, "Kernel I/O : fast allocation successful from ring %d\n", ctx->fd); |
---|
263 | |
---|
264 | __fill( sqes, want, idxs, ctx ); |
---|
265 | return ctx; |
---|
266 | } |
---|
267 | // The fast path failed, fallback |
---|
268 | __STATS__( true, io.alloc.fail += 1; ) |
---|
269 | |
---|
270 | // Fast path failed, fallback on arbitration |
---|
271 | __STATS__( true, io.alloc.slow += 1; ) |
---|
272 | enable_interrupts(); |
---|
273 | |
---|
274 | $io_arbiter * ioarb = proc->cltr->io.arbiter; |
---|
275 | /* paranoid */ verify( ioarb ); |
---|
276 | |
---|
277 | __cfadbg_print_safe(io, "Kernel I/O : falling back on arbiter for allocation\n"); |
---|
278 | |
---|
279 | struct $io_context * ret = __ioarbiter_allocate(*ioarb, idxs, want); |
---|
280 | |
---|
281 | __cfadbg_print_safe(io, "Kernel I/O : slow allocation completed from ring %d\n", ret->fd); |
---|
282 | |
---|
283 | __fill( sqes, want, idxs,ret ); |
---|
284 | return ret; |
---|
285 | } |
---|
286 | |
---|
287 | //============================================================================================= |
---|
288 | // submission |
---|
289 | static inline void __submit_only( struct $io_context * ctx, __u32 idxs[], __u32 have) { |
---|
290 | // We can proceed to the fast path |
---|
291 | // Get the right objects |
---|
292 | __sub_ring_t & sq = ctx->sq; |
---|
293 | const __u32 mask = *sq.mask; |
---|
294 | __u32 tail = *sq.kring.tail; |
---|
295 | |
---|
296 | // Add the sqes to the array |
---|
297 | for( i; have ) { |
---|
298 | __cfadbg_print_safe(io, "Kernel I/O : __submit loop\n"); |
---|
299 | sq.kring.array[ (tail + i) & mask ] = idxs[i]; |
---|
300 | } |
---|
301 | |
---|
302 | // Make the sqes visible to the submitter |
---|
303 | __atomic_store_n(sq.kring.tail, tail + have, __ATOMIC_RELEASE); |
---|
304 | sq.to_submit += have; |
---|
305 | |
---|
306 | ctx->proc->io.pending = true; |
---|
307 | ctx->proc->io.dirty = true; |
---|
308 | } |
---|
309 | |
---|
310 | static inline void __submit( struct $io_context * ctx, __u32 idxs[], __u32 have, bool lazy) { |
---|
311 | __sub_ring_t & sq = ctx->sq; |
---|
312 | __submit_only(ctx, idxs, have); |
---|
313 | |
---|
314 | if(sq.to_submit > 30) { |
---|
315 | __tls_stats()->io.flush.full++; |
---|
316 | __cfa_io_flush( ctx->proc, 0 ); |
---|
317 | } |
---|
318 | if(!lazy) { |
---|
319 | __tls_stats()->io.flush.eager++; |
---|
320 | __cfa_io_flush( ctx->proc, 0 ); |
---|
321 | } |
---|
322 | } |
---|
323 | |
---|
324 | void cfa_io_submit( struct $io_context * inctx, __u32 idxs[], __u32 have, bool lazy ) __attribute__((nonnull (1))) { |
---|
325 | __cfadbg_print_safe(io, "Kernel I/O : attempting to submit %u (%s)\n", have, lazy ? "lazy" : "eager"); |
---|
326 | |
---|
327 | disable_interrupts(); |
---|
328 | processor * proc = __cfaabi_tls.this_processor; |
---|
329 | $io_context * ctx = proc->io.ctx; |
---|
330 | /* paranoid */ verify( __cfaabi_tls.this_processor ); |
---|
331 | /* paranoid */ verify( ctx ); |
---|
332 | |
---|
333 | // Can we proceed to the fast path |
---|
334 | if( ctx == inctx ) // We have the right instance? |
---|
335 | { |
---|
336 | __submit(ctx, idxs, have, lazy); |
---|
337 | |
---|
338 | // Mark the instance as no longer in-use, re-enable interrupts and return |
---|
339 | __STATS__( true, io.submit.fast += 1; ) |
---|
340 | enable_interrupts(); |
---|
341 | |
---|
342 | __cfadbg_print_safe(io, "Kernel I/O : submitted on fast path\n"); |
---|
343 | return; |
---|
344 | } |
---|
345 | |
---|
346 | // Fast path failed, fallback on arbitration |
---|
347 | __STATS__( true, io.submit.slow += 1; ) |
---|
348 | enable_interrupts(); |
---|
349 | |
---|
350 | __cfadbg_print_safe(io, "Kernel I/O : falling back on arbiter for submission\n"); |
---|
351 | |
---|
352 | __ioarbiter_submit(inctx, idxs, have, lazy); |
---|
353 | } |
---|
354 | |
---|
355 | //============================================================================================= |
---|
356 | // Flushing |
---|
357 | // Go through the ring's submit queue and release everything that has already been consumed |
---|
358 | // by io_uring |
---|
359 | // This cannot be done by multiple threads |
---|
360 | static __u32 __release_sqes( struct $io_context & ctx ) { |
---|
361 | const __u32 mask = *ctx.sq.mask; |
---|
362 | |
---|
363 | __attribute__((unused)) |
---|
364 | __u32 ctail = *ctx.sq.kring.tail; // get the current tail of the queue |
---|
365 | __u32 chead = *ctx.sq.kring.head; // get the current head of the queue |
---|
366 | __u32 phead = ctx.sq.kring.released; // get the head the last time we were here |
---|
367 | |
---|
368 | __u32 ftail = ctx.sq.free_ring.tail; // get the current tail of the queue |
---|
369 | |
---|
370 | // the 3 fields are organized like this diagram |
---|
371 | // except it's are ring |
---|
372 | // ---+--------+--------+---- |
---|
373 | // ---+--------+--------+---- |
---|
374 | // ^ ^ ^ |
---|
375 | // phead chead ctail |
---|
376 | |
---|
377 | // make sure ctail doesn't wrap around and reach phead |
---|
378 | /* paranoid */ verify( |
---|
379 | (ctail >= chead && chead >= phead) |
---|
380 | || (chead >= phead && phead >= ctail) |
---|
381 | || (phead >= ctail && ctail >= chead) |
---|
382 | ); |
---|
383 | |
---|
384 | // find the range we need to clear |
---|
385 | __u32 count = chead - phead; |
---|
386 | |
---|
387 | if(count == 0) { |
---|
388 | return 0; |
---|
389 | } |
---|
390 | |
---|
391 | // We acquired an previous-head/current-head range |
---|
392 | // go through the range and release the sqes |
---|
393 | for( i; count ) { |
---|
394 | __cfadbg_print_safe(io, "Kernel I/O : release loop\n"); |
---|
395 | __u32 idx = ctx.sq.kring.array[ (phead + i) & mask ]; |
---|
396 | ctx.sq.free_ring.array[ (ftail + i) & mask ] = idx; |
---|
397 | } |
---|
398 | |
---|
399 | ctx.sq.kring.released = chead; // note up to were we processed |
---|
400 | __atomic_store_n(&ctx.sq.free_ring.tail, ftail + count, __ATOMIC_SEQ_CST); |
---|
401 | |
---|
402 | __ioarbiter_notify(ctx); |
---|
403 | |
---|
404 | return count; |
---|
405 | } |
---|
406 | |
---|
407 | //============================================================================================= |
---|
408 | // I/O Arbiter |
---|
409 | //============================================================================================= |
---|
410 | static inline bool enqueue(__outstanding_io_queue & queue, __outstanding_io & item) { |
---|
411 | bool was_empty; |
---|
412 | |
---|
413 | // Lock the list, it's not thread safe |
---|
414 | lock( queue.lock __cfaabi_dbg_ctx2 ); |
---|
415 | { |
---|
416 | was_empty = empty(queue.queue); |
---|
417 | |
---|
418 | // Add our request to the list |
---|
419 | add( queue.queue, item ); |
---|
420 | |
---|
421 | // Mark as pending |
---|
422 | __atomic_store_n( &queue.empty, false, __ATOMIC_SEQ_CST ); |
---|
423 | } |
---|
424 | unlock( queue.lock ); |
---|
425 | |
---|
426 | return was_empty; |
---|
427 | } |
---|
428 | |
---|
429 | static inline bool empty(__outstanding_io_queue & queue ) { |
---|
430 | return __atomic_load_n( &queue.empty, __ATOMIC_SEQ_CST); |
---|
431 | } |
---|
432 | |
---|
433 | static $io_context * __ioarbiter_allocate( $io_arbiter & this, __u32 idxs[], __u32 want ) { |
---|
434 | __cfadbg_print_safe(io, "Kernel I/O : arbiter allocating\n"); |
---|
435 | |
---|
436 | __STATS__( false, io.alloc.block += 1; ) |
---|
437 | |
---|
438 | // No one has any resources left, wait for something to finish |
---|
439 | // We need to add ourself to a list of pending allocs and wait for an answer |
---|
440 | __pending_alloc pa; |
---|
441 | pa.idxs = idxs; |
---|
442 | pa.want = want; |
---|
443 | |
---|
444 | enqueue(this.pending, (__outstanding_io&)pa); |
---|
445 | |
---|
446 | wait( pa.sem ); |
---|
447 | |
---|
448 | return pa.ctx; |
---|
449 | |
---|
450 | } |
---|
451 | |
---|
452 | static void __ioarbiter_notify( $io_arbiter & this, $io_context * ctx ) { |
---|
453 | /* paranoid */ verify( !empty(this.pending.queue) ); |
---|
454 | |
---|
455 | lock( this.pending.lock __cfaabi_dbg_ctx2 ); |
---|
456 | { |
---|
457 | while( !empty(this.pending.queue) ) { |
---|
458 | __cfadbg_print_safe(io, "Kernel I/O : notifying\n"); |
---|
459 | __u32 have = ctx->sq.free_ring.tail - ctx->sq.free_ring.head; |
---|
460 | __pending_alloc & pa = (__pending_alloc&)head( this.pending.queue ); |
---|
461 | |
---|
462 | if( have > pa.want ) goto DONE; |
---|
463 | drop( this.pending.queue ); |
---|
464 | |
---|
465 | /* paranoid */__attribute__((unused)) bool ret = |
---|
466 | |
---|
467 | __alloc(ctx, pa.idxs, pa.want); |
---|
468 | |
---|
469 | /* paranoid */ verify( ret ); |
---|
470 | |
---|
471 | pa.ctx = ctx; |
---|
472 | |
---|
473 | post( pa.sem ); |
---|
474 | } |
---|
475 | |
---|
476 | this.pending.empty = true; |
---|
477 | DONE:; |
---|
478 | } |
---|
479 | unlock( this.pending.lock ); |
---|
480 | } |
---|
481 | |
---|
482 | static void __ioarbiter_notify( $io_context & ctx ) { |
---|
483 | if(!empty( ctx.arbiter->pending )) { |
---|
484 | __ioarbiter_notify( *ctx.arbiter, &ctx ); |
---|
485 | } |
---|
486 | } |
---|
487 | |
---|
488 | // Simply append to the pending |
---|
489 | static void __ioarbiter_submit( $io_context * ctx, __u32 idxs[], __u32 have, bool lazy ) { |
---|
490 | __cfadbg_print_safe(io, "Kernel I/O : submitting %u from the arbiter to context %u\n", have, ctx->fd); |
---|
491 | |
---|
492 | __cfadbg_print_safe(io, "Kernel I/O : waiting to submit %u\n", have); |
---|
493 | |
---|
494 | __external_io ei; |
---|
495 | ei.idxs = idxs; |
---|
496 | ei.have = have; |
---|
497 | ei.lazy = lazy; |
---|
498 | |
---|
499 | bool we = enqueue(ctx->ext_sq, (__outstanding_io&)ei); |
---|
500 | |
---|
501 | ctx->proc->io.pending = true; |
---|
502 | |
---|
503 | if( we ) { |
---|
504 | sigval_t value = { PREEMPT_IO }; |
---|
505 | pthread_sigqueue(ctx->proc->kernel_thread, SIGUSR1, value); |
---|
506 | } |
---|
507 | |
---|
508 | wait( ei.sem ); |
---|
509 | |
---|
510 | __cfadbg_print_safe(io, "Kernel I/O : %u submitted from arbiter\n", have); |
---|
511 | } |
---|
512 | |
---|
513 | static void __ioarbiter_flush( $io_context & ctx ) { |
---|
514 | if(!empty( ctx.ext_sq )) { |
---|
515 | __STATS__( false, io.flush.external += 1; ) |
---|
516 | |
---|
517 | __cfadbg_print_safe(io, "Kernel I/O : arbiter flushing\n"); |
---|
518 | |
---|
519 | lock( ctx.ext_sq.lock __cfaabi_dbg_ctx2 ); |
---|
520 | { |
---|
521 | while( !empty(ctx.ext_sq.queue) ) { |
---|
522 | __external_io & ei = (__external_io&)drop( ctx.ext_sq.queue ); |
---|
523 | |
---|
524 | __submit_only(&ctx, ei.idxs, ei.have); |
---|
525 | |
---|
526 | post( ei.sem ); |
---|
527 | } |
---|
528 | |
---|
529 | ctx.ext_sq.empty = true; |
---|
530 | } |
---|
531 | unlock(ctx.ext_sq.lock ); |
---|
532 | } |
---|
533 | } |
---|
534 | |
---|
535 | #if defined(CFA_WITH_IO_URING_IDLE) |
---|
536 | bool __kernel_read(processor * proc, io_future_t & future, iovec & iov, int fd) { |
---|
537 | $io_context * ctx = proc->io.ctx; |
---|
538 | /* paranoid */ verify( ! __preemption_enabled() ); |
---|
539 | /* paranoid */ verify( proc == __cfaabi_tls.this_processor ); |
---|
540 | /* paranoid */ verify( ctx ); |
---|
541 | |
---|
542 | __u32 idx; |
---|
543 | struct io_uring_sqe * sqe; |
---|
544 | |
---|
545 | // We can proceed to the fast path |
---|
546 | if( !__alloc(ctx, &idx, 1) ) return false; |
---|
547 | |
---|
548 | // Allocation was successful |
---|
549 | __fill( &sqe, 1, &idx, ctx ); |
---|
550 | |
---|
551 | sqe->user_data = (uintptr_t)&future; |
---|
552 | sqe->flags = 0; |
---|
553 | sqe->fd = fd; |
---|
554 | sqe->off = 0; |
---|
555 | sqe->ioprio = 0; |
---|
556 | sqe->fsync_flags = 0; |
---|
557 | sqe->__pad2[0] = 0; |
---|
558 | sqe->__pad2[1] = 0; |
---|
559 | sqe->__pad2[2] = 0; |
---|
560 | |
---|
561 | #if defined(CFA_HAVE_IORING_OP_READ) |
---|
562 | sqe->opcode = IORING_OP_READ; |
---|
563 | sqe->addr = (uint64_t)iov.iov_base; |
---|
564 | sqe->len = iov.iov_len; |
---|
565 | #elif defined(CFA_HAVE_READV) && defined(CFA_HAVE_IORING_OP_READV) |
---|
566 | sqe->opcode = IORING_OP_READV; |
---|
567 | sqe->addr = (uintptr_t)&iov; |
---|
568 | sqe->len = 1; |
---|
569 | #else |
---|
570 | #error CFA_WITH_IO_URING_IDLE but none of CFA_HAVE_READV, CFA_HAVE_IORING_OP_READV or CFA_HAVE_IORING_OP_READ defined |
---|
571 | #endif |
---|
572 | |
---|
573 | asm volatile("": : :"memory"); |
---|
574 | |
---|
575 | /* paranoid */ verify( sqe->user_data == (uintptr_t)&future ); |
---|
576 | __submit( ctx, &idx, 1, true ); |
---|
577 | |
---|
578 | /* paranoid */ verify( proc == __cfaabi_tls.this_processor ); |
---|
579 | /* paranoid */ verify( ! __preemption_enabled() ); |
---|
580 | |
---|
581 | return true; |
---|
582 | } |
---|
583 | #endif |
---|
584 | #endif |
---|