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setup.cfa@ 32c2c5e

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Last change on this file since 32c2c5e was 2fab24e3, checked in by Thierry Delisle <tdelisle@…>, 5 years ago
Fixed some warnings and printing.
Property mode set to `100644`
File size: 18.9 KB

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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 __kernel_io_startup() {
29	// Nothing to do without io_uring
30	}
31
32	void __kernel_io_shutdown() {
33	// Nothing to do without io_uring
34	}
35
36	void ?{}(io_context_params & this) {}
37
38	void ?{}(io_context & this, struct cluster & cl) {}
39	void ?{}(io_context & this, struct cluster & cl, const io_context_params & params) {}
40
41	void ^?{}(io_context & this) {}
42	void ^?{}(io_context & this, bool cluster_context) {}
43
44	void register_fixed_files( io_context &, int *, unsigned ) {}
45	void register_fixed_files( cluster &, int *, unsigned ) {}
46
47	#else
48	#include <errno.h>
49	#include <stdint.h>
50	#include <string.h>
51	#include <signal.h>
52	#include <unistd.h>
53
54	extern "C" {
55	#include <pthread.h>
56	#include <sys/epoll.h>
57	#include <sys/eventfd.h>
58	#include <sys/mman.h>
59	#include <sys/syscall.h>
60
61	#include <linux/io_uring.h>
62	}
63
64	#include "bitmanip.hfa"
65	#include "kernel_private.hfa"
66	#include "thread.hfa"
67
68	void ?{}(io_context_params & this) {
69	this.num_entries = 256;
70	this.num_ready = 256;
71	this.submit_aff = -1;
72	this.eager_submits = false;
73	this.poller_submits = false;
74	this.poll_submit = false;
75	this.poll_complete = false;
76	}
77
78	static void * __io_poller_slow( void * arg );
79
80	// Weirdly, some systems that do support io_uring don't actually define these
81	#ifdef __alpha__
82	/*
83	* alpha is the only exception, all other architectures
84	* have common numbers for new system calls.
85	*/
86	#ifndef __NR_io_uring_setup
87	#define __NR_io_uring_setup 535
88	#endif
89	#ifndef __NR_io_uring_enter
90	#define __NR_io_uring_enter 536
91	#endif
92	#ifndef __NR_io_uring_register
93	#define __NR_io_uring_register 537
94	#endif
95	#else /* !__alpha__ */
96	#ifndef __NR_io_uring_setup
97	#define __NR_io_uring_setup 425
98	#endif
99	#ifndef __NR_io_uring_enter
100	#define __NR_io_uring_enter 426
101	#endif
102	#ifndef __NR_io_uring_register
103	#define __NR_io_uring_register 427
104	#endif
105	#endif
106
107	//=============================================================================================
108	// I/O Startup / Shutdown logic + Master Poller
109	//=============================================================================================
110
111	// IO Master poller loop forward
112	static void * iopoll_loop( __attribute__((unused)) void * args );
113
114	static struct {
115	pthread_t thrd; // pthread handle to io poller thread
116	void * stack; // pthread stack for io poller thread
117	int epollfd; // file descriptor to the epoll instance
118	volatile bool run; // Whether or not to continue
119	volatile bool stopped; // Whether the poller has finished running
120	volatile uint64_t epoch; // Epoch used for memory reclamation
121	} iopoll;
122
123	void __kernel_io_startup(void) {
124	__cfadbg_print_safe(io_core, "Kernel : Creating EPOLL instance\n" );
125
126	iopoll.epollfd = epoll_create1(0);
127	if (iopoll.epollfd == -1) {
128	abort( "internal error, epoll_create1\n");
129	}
130
131	__cfadbg_print_safe(io_core, "Kernel : Starting io poller thread\n" );
132
133	iopoll.stack = __create_pthread( &iopoll.thrd, iopoll_loop, 0p );
134	iopoll.run = true;
135	iopoll.stopped = false;
136	iopoll.epoch = 0;
137	}
138
139	void __kernel_io_shutdown(void) {
140	// Notify the io poller thread of the shutdown
141	iopoll.run = false;
142	sigval val = { 1 };
143	pthread_sigqueue( iopoll.thrd, SIGUSR1, val );
144
145	// Wait for the io poller thread to finish
146
147	__destroy_pthread( iopoll.thrd, iopoll.stack, 0p );
148
149	int ret = close(iopoll.epollfd);
150	if (ret == -1) {
151	abort( "internal error, close epoll\n");
152	}
153
154	// Io polling is now fully stopped
155
156	__cfadbg_print_safe(io_core, "Kernel : IO poller stopped\n" );
157	}
158
159	static void * iopoll_loop( __attribute__((unused)) void * args ) {
160	__processor_id_t id;
161	id.full_proc = false;
162	id.id = doregister(&id);
163	__cfaabi_tls.this_proc_id = &id;
164	__cfadbg_print_safe(io_core, "Kernel : IO poller thread starting\n" );
165
166	// Block signals to control when they arrive
167	sigset_t mask;
168	sigfillset(&mask);
169	if ( pthread_sigmask( SIG_BLOCK, &mask, 0p ) == -1 ) {
170	abort( "internal error, pthread_sigmask" );
171	}
172
173	sigdelset( &mask, SIGUSR1 );
174
175	// Create sufficient events
176	struct epoll_event events[10];
177	// Main loop
178	while( iopoll.run ) {
179	__cfadbg_print_safe(io_core, "Kernel I/O - epoll : waiting on io_uring contexts\n");
180
181	// increment the epoch to notify any deleters we are starting a new cycle
182	__atomic_fetch_add(&iopoll.epoch, 1, __ATOMIC_SEQ_CST);
183
184	// Wait for events
185	int nfds = epoll_pwait( iopoll.epollfd, events, 10, -1, &mask );
186
187	__cfadbg_print_safe(io_core, "Kernel I/O - epoll : %d io contexts events, waking up\n", nfds);
188
189	// Check if an error occured
190	if (nfds == -1) {
191	if( errno == EINTR ) continue;
192	abort( "internal error, pthread_sigmask" );
193	}
194
195	for(i; nfds) {
196	$io_ctx_thread * io_ctx = ($io_ctx_thread *)(uintptr_t)events[i].data.u64;
197	/* paranoid */ verify( io_ctx );
198	__cfadbg_print_safe(io_core, "Kernel I/O - epoll : Unparking io poller %d (%p)\n", io_ctx->ring->fd, io_ctx);
199	#if !defined( __CFA_NO_STATISTICS__ )
200	__cfaabi_tls.this_stats = io_ctx->self.curr_cluster->stats;
201	#endif
202
203	eventfd_t v;
204	eventfd_read(io_ctx->ring->efd, &v);
205
206	post( io_ctx->sem );
207	}
208	}
209
210	__atomic_store_n(&iopoll.stopped, true, __ATOMIC_SEQ_CST);
211
212	__cfadbg_print_safe(io_core, "Kernel : IO poller thread stopping\n" );
213	unregister(&id);
214	return 0p;
215	}
216
217	//=============================================================================================
218	// I/O Context Constrution/Destruction
219	//=============================================================================================
220
221	void ?{}($io_ctx_thread & this, struct cluster & cl) { (this.self){ "IO Poller", cl }; }
222	void main( $io_ctx_thread & this );
223	static inline $thread * get_thread( $io_ctx_thread & this ) { return &this.self; }
224	void ^?{}( $io_ctx_thread & mutex this ) {}
225
226	static void __io_create ( __io_data & this, const io_context_params & params_in );
227	static void __io_destroy( __io_data & this );
228
229	void ?{}(io_context & this, struct cluster & cl, const io_context_params & params) {
230	(this.thrd){ cl };
231	this.thrd.ring = malloc();
232	__cfadbg_print_safe(io_core, "Kernel I/O : Creating ring for io_context %p\n", &this);
233	__io_create( *this.thrd.ring, params );
234
235	__cfadbg_print_safe(io_core, "Kernel I/O : Starting poller thread for io_context %p\n", &this);
236	this.thrd.done = false;
237	__thrd_start( this.thrd, main );
238
239	__cfadbg_print_safe(io_core, "Kernel I/O : io_context %p ready\n", &this);
240	}
241
242	void ?{}(io_context & this, struct cluster & cl) {
243	io_context_params params;
244	(this){ cl, params };
245	}
246
247	void ^?{}(io_context & this, bool cluster_context) {
248	__cfadbg_print_safe(io_core, "Kernel I/O : tearing down io_context %p\n", &this);
249
250	// Notify the thread of the shutdown
251	__atomic_store_n(&this.thrd.done, true, __ATOMIC_SEQ_CST);
252
253	// If this is an io_context within a cluster, things get trickier
254	$thread & thrd = this.thrd.self;
255	if( cluster_context ) {
256	// We are about to do weird things with the threads
257	// we don't need interrupts to complicate everything
258	disable_interrupts();
259
260	// Get cluster info
261	cluster & cltr = *thrd.curr_cluster;
262	/* paranoid */ verify( cltr.idles.total == 0 \|\| &cltr == mainCluster );
263	/* paranoid */ verify( !ready_mutate_islocked() );
264
265	// We need to adjust the clean-up based on where the thread is
266	if( thrd.state == Ready \|\| thrd.preempted != __NO_PREEMPTION ) {
267	// This is the tricky case
268	// The thread was preempted or ready to run and now it is on the ready queue
269	// but the cluster is shutting down, so there aren't any processors to run the ready queue
270	// the solution is to steal the thread from the ready-queue and pretend it was blocked all along
271
272	ready_schedule_lock();
273	// The thread should on the list
274	/* paranoid */ verify( thrd.link.next != 0p );
275
276	// Remove the thread from the ready queue of this cluster
277	// The thread should be the last on the list
278	__attribute__((unused)) bool removed = remove_head( &cltr, &thrd );
279	/* paranoid */ verify( removed );
280	thrd.link.next = 0p;
281	thrd.link.prev = 0p;
282
283	// Fixup the thread state
284	thrd.state = Blocked;
285	thrd.ticket = TICKET_BLOCKED;
286	thrd.preempted = __NO_PREEMPTION;
287
288	ready_schedule_unlock();
289
290	// Pretend like the thread was blocked all along
291	}
292	// !!! This is not an else if !!!
293	// Ok, now the thread is blocked (whether we cheated to get here or not)
294	if( thrd.state == Blocked ) {
295	// This is the "easy case"
296	// The thread is parked and can easily be moved to active cluster
297	verify( thrd.curr_cluster != active_cluster() \|\| thrd.curr_cluster == mainCluster );
298	thrd.curr_cluster = active_cluster();
299
300	// unpark the fast io_poller
301	unpark( &thrd );
302	}
303	else {
304	// The thread is in a weird state
305	// I don't know what to do here
306	abort("io_context poller thread is in unexpected state, cannot clean-up correctly\n");
307	}
308
309	// The weird thread kidnapping stuff is over, restore interrupts.
310	enable_interrupts( __cfaabi_dbg_ctx );
311	} else {
312	post( this.thrd.sem );
313	}
314
315	^(this.thrd){};
316	__cfadbg_print_safe(io_core, "Kernel I/O : Stopped poller thread for io_context %p\n", &this);
317
318	__io_destroy( *this.thrd.ring );
319	__cfadbg_print_safe(io_core, "Kernel I/O : Destroyed ring for io_context %p\n", &this);
320
321	free(this.thrd.ring);
322	}
323
324	void ^?{}(io_context & this) {
325	^(this){ false };
326	}
327
328	extern void __disable_interrupts_hard();
329	extern void __enable_interrupts_hard();
330
331	static void __io_create( __io_data & this, const io_context_params & params_in ) {
332	// Step 1 : call to setup
333	struct io_uring_params params;
334	memset(&params, 0, sizeof(params));
335	if( params_in.poll_submit ) params.flags \|= IORING_SETUP_SQPOLL;
336	if( params_in.poll_complete ) params.flags \|= IORING_SETUP_IOPOLL;
337
338	__u32 nentries = params_in.num_entries != 0 ? params_in.num_entries : 256;
339	if( !is_pow2(nentries) ) {
340	abort("ERROR: I/O setup 'num_entries' must be a power of 2\n");
341	}
342	if( params_in.poller_submits && params_in.eager_submits ) {
343	abort("ERROR: I/O setup 'poller_submits' and 'eager_submits' cannot be used together\n");
344	}
345
346	int fd = syscall(__NR_io_uring_setup, nentries, &params );
347	if(fd < 0) {
348	abort("KERNEL ERROR: IO_URING SETUP - %s\n", strerror(errno));
349	}
350
351	// Step 2 : mmap result
352	memset( &this, 0, sizeof(struct __io_data) );
353	struct __submition_data & sq = this.submit_q;
354	struct __completion_data & cq = this.completion_q;
355
356	// calculate the right ring size
357	sq.ring_sz = params.sq_off.array + (params.sq_entries * sizeof(unsigned) );
358	cq.ring_sz = params.cq_off.cqes + (params.cq_entries * sizeof(struct io_uring_cqe));
359
360	// Requires features
361	#if defined(IORING_FEAT_SINGLE_MMAP)
362	// adjust the size according to the parameters
363	if ((params.features & IORING_FEAT_SINGLE_MMAP) != 0) {
364	cq.ring_sz = sq.ring_sz = max(cq.ring_sz, sq.ring_sz);
365	}
366	#endif
367
368	// mmap the Submit Queue into existence
369	sq.ring_ptr = mmap(0, sq.ring_sz, PROT_READ \| PROT_WRITE, MAP_SHARED \| MAP_POPULATE, fd, IORING_OFF_SQ_RING);
370	if (sq.ring_ptr == (void*)MAP_FAILED) {
371	abort("KERNEL ERROR: IO_URING MMAP1 - %s\n", strerror(errno));
372	}
373
374	// Requires features
375	#if defined(IORING_FEAT_SINGLE_MMAP)
376	// mmap the Completion Queue into existence (may or may not be needed)
377	if ((params.features & IORING_FEAT_SINGLE_MMAP) != 0) {
378	cq.ring_ptr = sq.ring_ptr;
379	}
380	else
381	#endif
382	{
383	// We need multiple call to MMAP
384	cq.ring_ptr = mmap(0, cq.ring_sz, PROT_READ \| PROT_WRITE, MAP_SHARED \| MAP_POPULATE, fd, IORING_OFF_CQ_RING);
385	if (cq.ring_ptr == (void*)MAP_FAILED) {
386	munmap(sq.ring_ptr, sq.ring_sz);
387	abort("KERNEL ERROR: IO_URING MMAP2 - %s\n", strerror(errno));
388	}
389	}
390
391	// mmap the submit queue entries
392	size_t size = params.sq_entries * sizeof(struct io_uring_sqe);
393	sq.sqes = (struct io_uring_sqe *)mmap(0, size, PROT_READ \| PROT_WRITE, MAP_SHARED \| MAP_POPULATE, fd, IORING_OFF_SQES);
394	if (sq.sqes == (struct io_uring_sqe *)MAP_FAILED) {
395	munmap(sq.ring_ptr, sq.ring_sz);
396	if (cq.ring_ptr != sq.ring_ptr) munmap(cq.ring_ptr, cq.ring_sz);
397	abort("KERNEL ERROR: IO_URING MMAP3 - %s\n", strerror(errno));
398	}
399
400	// Step 3 : Initialize the data structure
401	// Get the pointers from the kernel to fill the structure
402	// submit queue
403	sq.head = (volatile __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.head);
404	sq.tail = (volatile __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.tail);
405	sq.mask = ( const __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.ring_mask);
406	sq.num = ( const __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.ring_entries);
407	sq.flags = ( __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.flags);
408	sq.dropped = ( __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.dropped);
409	sq.array = ( __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.array);
410	sq.prev_head = *sq.head;
411
412	{
413	const __u32 num = *sq.num;
414	for( i; num ) {
415	__sqe_clean( &sq.sqes[i] );
416	}
417	}
418
419	(sq.submit_lock){};
420	(sq.release_lock){};
421
422	if( params_in.poller_submits \|\| params_in.eager_submits ) {
423	/* paranoid */ verify( is_pow2( params_in.num_ready ) \|\| (params_in.num_ready < 8) );
424	sq.ready_cnt = max( params_in.num_ready, 8 );
425	sq.ready = alloc( sq.ready_cnt, 64`align );
426	for(i; sq.ready_cnt) {
427	sq.ready[i] = -1ul32;
428	}
429	sq.prev_ready = 0;
430	}
431	else {
432	sq.ready_cnt = 0;
433	sq.ready = 0p;
434	sq.prev_ready = 0;
435	}
436
437	// completion queue
438	cq.head = (volatile __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.head);
439	cq.tail = (volatile __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.tail);
440	cq.mask = ( const __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.ring_mask);
441	cq.num = ( const __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.ring_entries);
442	cq.overflow = ( __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.overflow);
443	cq.cqes = (struct io_uring_cqe *)(((intptr_t)cq.ring_ptr) + params.cq_off.cqes);
444
445	// Step 4 : eventfd
446	// io_uring_register is so f*cking slow on some machine that it
447	// will never succeed if preemption isn't hard blocked
448	__disable_interrupts_hard();
449
450	int efd = eventfd(0, 0);
451	if (efd < 0) {
452	abort("KERNEL ERROR: IO_URING EVENTFD - %s\n", strerror(errno));
453	}
454
455	int ret = syscall( __NR_io_uring_register, fd, IORING_REGISTER_EVENTFD, &efd, 1);
456	if (ret < 0) {
457	abort("KERNEL ERROR: IO_URING EVENTFD REGISTER - %s\n", strerror(errno));
458	}
459
460	__enable_interrupts_hard();
461
462	// some paranoid checks
463	/* 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 );
464	/* paranoid / verifyf( (cq.num) >= nentries, "IO_URING Expected %u entries, got %u", nentries, *cq.num );
465	/* paranoid / verifyf( (cq.head) == 0, "IO_URING Expected head to be 0, got %u", *cq.head );
466	/* paranoid / verifyf( (cq.tail) == 0, "IO_URING Expected tail to be 0, got %u", *cq.tail );
467
468	/* 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 );
469	/* paranoid / verifyf( (sq.num) >= nentries, "IO_URING Expected %u entries, got %u", nentries, *sq.num );
470	/* paranoid / verifyf( (sq.head) == 0, "IO_URING Expected head to be 0, got %u", *sq.head );
471	/* paranoid / verifyf( (sq.tail) == 0, "IO_URING Expected tail to be 0, got %u", *sq.tail );
472
473	// Update the global ring info
474	this.ring_flags = params.flags;
475	this.fd = fd;
476	this.efd = efd;
477	this.eager_submits = params_in.eager_submits;
478	this.poller_submits = params_in.poller_submits;
479	}
480
481	static void __io_destroy( __io_data & this ) {
482	// Shutdown the io rings
483	struct __submition_data & sq = this.submit_q;
484	struct __completion_data & cq = this.completion_q;
485
486	// unmap the submit queue entries
487	munmap(sq.sqes, (sq.num) sizeof(struct io_uring_sqe));
488
489	// unmap the Submit Queue ring
490	munmap(sq.ring_ptr, sq.ring_sz);
491
492	// unmap the Completion Queue ring, if it is different
493	if (cq.ring_ptr != sq.ring_ptr) {
494	munmap(cq.ring_ptr, cq.ring_sz);
495	}
496
497	// close the file descriptor
498	close(this.fd);
499	close(this.efd);
500
501	free( this.submit_q.ready ); // Maybe null, doesn't matter
502	}
503
504	//=============================================================================================
505	// I/O Context Sleep
506	//=============================================================================================
507	static inline void __ioctx_epoll_ctl($io_ctx_thread & ctx, int op, const char * error) {
508	struct epoll_event ev;
509	ev.events = EPOLLIN \| EPOLLONESHOT;
510	ev.data.u64 = (__u64)&ctx;
511	int ret = epoll_ctl(iopoll.epollfd, op, ctx.ring->efd, &ev);
512	if (ret < 0) {
513	abort( "KERNEL ERROR: EPOLL %s - (%d) %s\n", error, (int)errno, strerror(errno) );
514	}
515	}
516
517	void __ioctx_register($io_ctx_thread & ctx) {
518	__ioctx_epoll_ctl(ctx, EPOLL_CTL_ADD, "ADD");
519	}
520
521	void __ioctx_prepare_block($io_ctx_thread & ctx) {
522	__cfadbg_print_safe(io_core, "Kernel I/O - epoll : Re-arming io poller %d (%p)\n", ctx.ring->fd, &ctx);
523	__ioctx_epoll_ctl(ctx, EPOLL_CTL_MOD, "REARM");
524	}
525
526	void __ioctx_unregister($io_ctx_thread & ctx) {
527	// Read the current epoch so we know when to stop
528	size_t curr = __atomic_load_n(&iopoll.epoch, __ATOMIC_SEQ_CST);
529
530	// Remove the fd from the iopoller
531	__ioctx_epoll_ctl(ctx, EPOLL_CTL_DEL, "REMOVE");
532
533	// Notify the io poller thread of the shutdown
534	iopoll.run = false;
535	sigval val = { 1 };
536	pthread_sigqueue( iopoll.thrd, SIGUSR1, val );
537
538	// Make sure all this is done
539	__atomic_thread_fence(__ATOMIC_SEQ_CST);
540
541	// Wait for the next epoch
542	while(curr == iopoll.epoch && !iopoll.stopped) Pause();
543	}
544
545	//=============================================================================================
546	// I/O Context Misc Setup
547	//=============================================================================================
548	void register_fixed_files( io_context & ctx, int * files, unsigned count ) {
549	int ret = syscall( __NR_io_uring_register, ctx.thrd.ring->fd, IORING_REGISTER_FILES, files, count );
550	if( ret < 0 ) {
551	abort( "KERNEL ERROR: IO_URING REGISTER - (%d) %s\n", (int)errno, strerror(errno) );
552	}
553
554	__cfadbg_print_safe( io_core, "Kernel I/O : Performed io_register for %p, returned %d\n", active_thread(), ret );
555	}
556
557	void register_fixed_files( cluster & cltr, int * files, unsigned count ) {
558	for(i; cltr.io.cnt) {
559	register_fixed_files( cltr.io.ctxs[i], files, count );
560	}
561	}
562	#endif

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