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setup.cfa@ 794db28

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Last change on this file since 794db28 was 1095ccd, checked in by Thierry Delisle <tdelisle@…>, 5 years ago
Added support for partial submit strategy
Property mode set to `100644`
File size: 16.2 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	#include "io/types.hfa"
20	#include "kernel.hfa"
21
22	#if !defined(CFA_HAVE_LINUX_IO_URING_H)
23	void __kernel_io_startup() {
24	// Nothing to do without io_uring
25	}
26
27	void __kernel_io_shutdown() {
28	// Nothing to do without io_uring
29	}
30
31	void ?{}(io_context_params & this) {}
32
33	void ?{}(io_context & this, struct cluster & cl) {}
34	void ?{}(io_context & this, struct cluster & cl, const io_context_params & params) {}
35
36	void ^?{}(io_context & this) {}
37	void ^?{}(io_context & this, bool cluster_context) {}
38
39	#else
40	#include <errno.h>
41	#include <stdint.h>
42	#include <string.h>
43	#include <signal.h>
44	#include <unistd.h>
45
46	extern "C" {
47	#include <pthread.h>
48	#include <sys/epoll.h>
49	#include <sys/mman.h>
50	#include <sys/syscall.h>
51
52	#include <linux/io_uring.h>
53	}
54
55	#include "bitmanip.hfa"
56	#include "kernel_private.hfa"
57	#include "thread.hfa"
58
59	void ?{}(io_context_params & this) {
60	this.num_entries = 256;
61	this.num_ready = 256;
62	this.submit_aff = -1;
63	this.eager_submits = false;
64	this.poller_submits = false;
65	this.poll_submit = false;
66	this.poll_complete = false;
67	}
68
69	static void * __io_poller_slow( void * arg );
70
71	// Weirdly, some systems that do support io_uring don't actually define these
72	#ifdef __alpha__
73	/*
74	* alpha is the only exception, all other architectures
75	* have common numbers for new system calls.
76	*/
77	#ifndef __NR_io_uring_setup
78	#define __NR_io_uring_setup 535
79	#endif
80	#ifndef __NR_io_uring_enter
81	#define __NR_io_uring_enter 536
82	#endif
83	#ifndef __NR_io_uring_register
84	#define __NR_io_uring_register 537
85	#endif
86	#else /* !__alpha__ */
87	#ifndef __NR_io_uring_setup
88	#define __NR_io_uring_setup 425
89	#endif
90	#ifndef __NR_io_uring_enter
91	#define __NR_io_uring_enter 426
92	#endif
93	#ifndef __NR_io_uring_register
94	#define __NR_io_uring_register 427
95	#endif
96	#endif
97
98	//=============================================================================================
99	// I/O Startup / Shutdown logic + Master Poller
100	//=============================================================================================
101
102	// IO Master poller loop forward
103	static void * iopoll_loop( __attribute__((unused)) void * args );
104
105	static struct {
106	pthread_t thrd; // pthread handle to io poller thread
107	void * stack; // pthread stack for io poller thread
108	int epollfd; // file descriptor to the epoll instance
109	volatile bool run; // Whether or not to continue
110	} iopoll;
111
112	void __kernel_io_startup(void) {
113	__cfaabi_dbg_print_safe( "Kernel : Creating EPOLL instance\n" );
114
115	iopoll.epollfd = epoll_create1(0);
116	if (iopoll.epollfd == -1) {
117	abort( "internal error, epoll_create1\n");
118	}
119
120	__cfaabi_dbg_print_safe( "Kernel : Starting io poller thread\n" );
121
122	iopoll.run = true;
123	iopoll.stack = __create_pthread( &iopoll.thrd, iopoll_loop, 0p );
124	}
125
126	void __kernel_io_shutdown(void) {
127	// Notify the io poller thread of the shutdown
128	iopoll.run = false;
129	sigval val = { 1 };
130	pthread_sigqueue( iopoll.thrd, SIGUSR1, val );
131
132	// Wait for the io poller thread to finish
133
134	pthread_join( iopoll.thrd, 0p );
135	free( iopoll.stack );
136
137	int ret = close(iopoll.epollfd);
138	if (ret == -1) {
139	abort( "internal error, close epoll\n");
140	}
141
142	// Io polling is now fully stopped
143
144	__cfaabi_dbg_print_safe( "Kernel : IO poller stopped\n" );
145	}
146
147	static void * iopoll_loop( __attribute__((unused)) void * args ) {
148	__processor_id_t id;
149	id.id = doregister(&id);
150	__cfaabi_dbg_print_safe( "Kernel : IO poller thread starting\n" );
151
152	// Block signals to control when they arrive
153	sigset_t mask;
154	sigfillset(&mask);
155	if ( pthread_sigmask( SIG_BLOCK, &mask, 0p ) == -1 ) {
156	abort( "internal error, pthread_sigmask" );
157	}
158
159	sigdelset( &mask, SIGUSR1 );
160
161	// Create sufficient events
162	struct epoll_event events[10];
163	// Main loop
164	while( iopoll.run ) {
165	// Wait for events
166	int nfds = epoll_pwait( iopoll.epollfd, events, 10, -1, &mask );
167
168	// Check if an error occured
169	if (nfds == -1) {
170	if( errno == EINTR ) continue;
171	abort( "internal error, pthread_sigmask" );
172	}
173
174	for(i; nfds) {
175	$io_ctx_thread * io_ctx = ($io_ctx_thread *)(uintptr_t)events[i].data.u64;
176	/* paranoid */ verify( io_ctx );
177	__cfadbg_print_safe(io_core, "Kernel I/O : Unparking io poller %p\n", io_ctx);
178	#if !defined( __CFA_NO_STATISTICS__ )
179	kernelTLS.this_stats = io_ctx->self.curr_cluster->stats;
180	#endif
181	__post( io_ctx->sem, &id );
182	}
183	}
184
185	__cfaabi_dbg_print_safe( "Kernel : IO poller thread stopping\n" );
186	unregister(&id);
187	return 0p;
188	}
189
190	//=============================================================================================
191	// I/O Context Constrution/Destruction
192	//=============================================================================================
193
194	void ?{}($io_ctx_thread & this, struct cluster & cl) { (this.self){ "IO Poller", cl }; }
195	void main( $io_ctx_thread & this );
196	static inline $thread * get_thread( $io_ctx_thread & this ) { return &this.self; }
197	void ^?{}( $io_ctx_thread & mutex this ) {}
198
199	static void __io_create ( __io_data & this, const io_context_params & params_in );
200	static void __io_destroy( __io_data & this );
201
202	void ?{}(io_context & this, struct cluster & cl, const io_context_params & params) {
203	(this.thrd){ cl };
204	this.thrd.ring = malloc();
205	__cfadbg_print_safe(io_core, "Kernel I/O : Creating ring for io_context %p\n", &this);
206	__io_create( *this.thrd.ring, params );
207
208	__cfadbg_print_safe(io_core, "Kernel I/O : Starting poller thread for io_context %p\n", &this);
209	this.thrd.done = false;
210	__thrd_start( this.thrd, main );
211
212	__cfadbg_print_safe(io_core, "Kernel I/O : io_context %p ready\n", &this);
213	}
214
215	void ?{}(io_context & this, struct cluster & cl) {
216	io_context_params params;
217	(this){ cl, params };
218	}
219
220	void ^?{}(io_context & this, bool cluster_context) {
221	__cfadbg_print_safe(io_core, "Kernel I/O : tearing down io_context %p\n", &this);
222
223	// Notify the thread of the shutdown
224	__atomic_store_n(&this.thrd.done, true, __ATOMIC_SEQ_CST);
225
226	// If this is an io_context within a cluster, things get trickier
227	$thread & thrd = this.thrd.self;
228	if( cluster_context ) {
229	cluster & cltr = *thrd.curr_cluster;
230	/* paranoid */ verify( cltr.idles.total == 0 \|\| &cltr == mainCluster );
231	/* paranoid */ verify( !ready_mutate_islocked() );
232
233	// We need to adjust the clean-up based on where the thread is
234	if( thrd.state == Ready \|\| thrd.preempted != __NO_PREEMPTION ) {
235
236	ready_schedule_lock( (struct __processor_id_t *)active_processor() );
237
238	// This is the tricky case
239	// The thread was preempted and now it is on the ready queue
240	// The thread should be the last on the list
241	/* paranoid */ verify( thrd.link.next != 0p );
242
243	// Remove the thread from the ready queue of this cluster
244	__attribute__((unused)) bool removed = remove_head( &cltr, &thrd );
245	/* paranoid */ verify( removed );
246	thrd.link.next = 0p;
247	thrd.link.prev = 0p;
248	__cfaabi_dbg_debug_do( thrd.unpark_stale = true );
249
250	// Fixup the thread state
251	thrd.state = Blocked;
252	thrd.ticket = 0;
253	thrd.preempted = __NO_PREEMPTION;
254
255	ready_schedule_unlock( (struct __processor_id_t *)active_processor() );
256
257	// Pretend like the thread was blocked all along
258	}
259	// !!! This is not an else if !!!
260	if( thrd.state == Blocked ) {
261
262	// This is the "easy case"
263	// The thread is parked and can easily be moved to active cluster
264	verify( thrd.curr_cluster != active_cluster() \|\| thrd.curr_cluster == mainCluster );
265	thrd.curr_cluster = active_cluster();
266
267	// unpark the fast io_poller
268	unpark( &thrd __cfaabi_dbg_ctx2 );
269	}
270	else {
271
272	// The thread is in a weird state
273	// I don't know what to do here
274	abort("io_context poller thread is in unexpected state, cannot clean-up correctly\n");
275	}
276	} else {
277	unpark( &thrd __cfaabi_dbg_ctx2 );
278	}
279
280	^(this.thrd){};
281	__cfadbg_print_safe(io_core, "Kernel I/O : Stopped poller thread for io_context %p\n", &this);
282
283	__io_destroy( *this.thrd.ring );
284	__cfadbg_print_safe(io_core, "Kernel I/O : Destroyed ring for io_context %p\n", &this);
285
286	free(this.thrd.ring);
287	}
288
289	void ^?{}(io_context & this) {
290	^(this){ false };
291	}
292
293	static void __io_create( __io_data & this, const io_context_params & params_in ) {
294	// Step 1 : call to setup
295	struct io_uring_params params;
296	memset(&params, 0, sizeof(params));
297	if( params_in.poll_submit ) params.flags \|= IORING_SETUP_SQPOLL;
298	if( params_in.poll_complete ) params.flags \|= IORING_SETUP_IOPOLL;
299
300	__u32 nentries = params_in.num_entries != 0 ? params_in.num_entries : 256;
301	if( !is_pow2(nentries) ) {
302	abort("ERROR: I/O setup 'num_entries' must be a power of 2\n");
303	}
304	if( params_in.poller_submits && params_in.eager_submits ) {
305	abort("ERROR: I/O setup 'poller_submits' and 'eager_submits' cannot be used together\n");
306	}
307
308	int fd = syscall(__NR_io_uring_setup, nentries, &params );
309	if(fd < 0) {
310	abort("KERNEL ERROR: IO_URING SETUP - %s\n", strerror(errno));
311	}
312
313	// Step 2 : mmap result
314	memset( &this, 0, sizeof(struct __io_data) );
315	struct __submition_data & sq = this.submit_q;
316	struct __completion_data & cq = this.completion_q;
317
318	// calculate the right ring size
319	sq.ring_sz = params.sq_off.array + (params.sq_entries * sizeof(unsigned) );
320	cq.ring_sz = params.cq_off.cqes + (params.cq_entries * sizeof(struct io_uring_cqe));
321
322	// Requires features
323	#if defined(IORING_FEAT_SINGLE_MMAP)
324	// adjust the size according to the parameters
325	if ((params.features & IORING_FEAT_SINGLE_MMAP) != 0) {
326	cq.ring_sz = sq.ring_sz = max(cq.ring_sz, sq.ring_sz);
327	}
328	#endif
329
330	// mmap the Submit Queue into existence
331	sq.ring_ptr = mmap(0, sq.ring_sz, PROT_READ \| PROT_WRITE, MAP_SHARED \| MAP_POPULATE, fd, IORING_OFF_SQ_RING);
332	if (sq.ring_ptr == (void*)MAP_FAILED) {
333	abort("KERNEL ERROR: IO_URING MMAP1 - %s\n", strerror(errno));
334	}
335
336	// Requires features
337	#if defined(IORING_FEAT_SINGLE_MMAP)
338	// mmap the Completion Queue into existence (may or may not be needed)
339	if ((params.features & IORING_FEAT_SINGLE_MMAP) != 0) {
340	cq.ring_ptr = sq.ring_ptr;
341	}
342	else
343	#endif
344	{
345	// We need multiple call to MMAP
346	cq.ring_ptr = mmap(0, cq.ring_sz, PROT_READ \| PROT_WRITE, MAP_SHARED \| MAP_POPULATE, fd, IORING_OFF_CQ_RING);
347	if (cq.ring_ptr == (void*)MAP_FAILED) {
348	munmap(sq.ring_ptr, sq.ring_sz);
349	abort("KERNEL ERROR: IO_URING MMAP2 - %s\n", strerror(errno));
350	}
351	}
352
353	// mmap the submit queue entries
354	size_t size = params.sq_entries * sizeof(struct io_uring_sqe);
355	sq.sqes = (struct io_uring_sqe *)mmap(0, size, PROT_READ \| PROT_WRITE, MAP_SHARED \| MAP_POPULATE, fd, IORING_OFF_SQES);
356	if (sq.sqes == (struct io_uring_sqe *)MAP_FAILED) {
357	munmap(sq.ring_ptr, sq.ring_sz);
358	if (cq.ring_ptr != sq.ring_ptr) munmap(cq.ring_ptr, cq.ring_sz);
359	abort("KERNEL ERROR: IO_URING MMAP3 - %s\n", strerror(errno));
360	}
361
362	// Get the pointers from the kernel to fill the structure
363	// submit queue
364	sq.head = (volatile __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.head);
365	sq.tail = (volatile __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.tail);
366	sq.mask = ( const __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.ring_mask);
367	sq.num = ( const __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.ring_entries);
368	sq.flags = ( __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.flags);
369	sq.dropped = ( __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.dropped);
370	sq.array = ( __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.array);
371	sq.prev_head = *sq.head;
372
373	{
374	const __u32 num = *sq.num;
375	for( i; num ) {
376	sq.sqes[i].user_data = 0ul64;
377	}
378	}
379
380	(sq.submit_lock){};
381	(sq.release_lock){};
382
383	if( params_in.poller_submits \|\| params_in.eager_submits ) {
384	/* paranoid */ verify( is_pow2( params_in.num_ready ) \|\| (params_in.num_ready < 8) );
385	sq.ready_cnt = max( params_in.num_ready, 8 );
386	sq.ready = alloc_align( 64, sq.ready_cnt );
387	for(i; sq.ready_cnt) {
388	sq.ready[i] = -1ul32;
389	}
390	sq.prev_ready = 0;
391	}
392	else {
393	sq.ready_cnt = 0;
394	sq.ready = 0p;
395	sq.prev_ready = 0;
396	}
397
398	// completion queue
399	cq.head = (volatile __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.head);
400	cq.tail = (volatile __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.tail);
401	cq.mask = ( const __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.ring_mask);
402	cq.num = ( const __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.ring_entries);
403	cq.overflow = ( __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.overflow);
404	cq.cqes = (struct io_uring_cqe *)(((intptr_t)cq.ring_ptr) + params.cq_off.cqes);
405
406	// some paranoid checks
407	/* 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 );
408	/* paranoid / verifyf( (cq.num) >= nentries, "IO_URING Expected %u entries, got %u", nentries, *cq.num );
409	/* paranoid / verifyf( (cq.head) == 0, "IO_URING Expected head to be 0, got %u", *cq.head );
410	/* paranoid / verifyf( (cq.tail) == 0, "IO_URING Expected tail to be 0, got %u", *cq.tail );
411
412	/* 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 );
413	/* paranoid / verifyf( (sq.num) >= nentries, "IO_URING Expected %u entries, got %u", nentries, *sq.num );
414	/* paranoid / verifyf( (sq.head) == 0, "IO_URING Expected head to be 0, got %u", *sq.head );
415	/* paranoid / verifyf( (sq.tail) == 0, "IO_URING Expected tail to be 0, got %u", *sq.tail );
416
417	// Update the global ring info
418	this.ring_flags = params.flags;
419	this.fd = fd;
420	this.eager_submits = params_in.eager_submits;
421	this.poller_submits = params_in.poller_submits;
422	}
423
424	static void __io_destroy( __io_data & this ) {
425	// Shutdown the io rings
426	struct __submition_data & sq = this.submit_q;
427	struct __completion_data & cq = this.completion_q;
428
429	// unmap the submit queue entries
430	munmap(sq.sqes, (sq.num) sizeof(struct io_uring_sqe));
431
432	// unmap the Submit Queue ring
433	munmap(sq.ring_ptr, sq.ring_sz);
434
435	// unmap the Completion Queue ring, if it is different
436	if (cq.ring_ptr != sq.ring_ptr) {
437	munmap(cq.ring_ptr, cq.ring_sz);
438	}
439
440	// close the file descriptor
441	close(this.fd);
442
443	free( this.submit_q.ready ); // Maybe null, doesn't matter
444	}
445
446	//=============================================================================================
447	// I/O Context Sleep
448	//=============================================================================================
449
450	void __ioctx_register($io_ctx_thread & ctx, struct epoll_event & ev) {
451	ev.events = EPOLLIN \| EPOLLONESHOT;
452	ev.data.u64 = (__u64)&ctx;
453	int ret = epoll_ctl(iopoll.epollfd, EPOLL_CTL_ADD, ctx.ring->fd, &ev);
454	if (ret < 0) {
455	abort( "KERNEL ERROR: EPOLL ADD - (%d) %s\n", (int)errno, strerror(errno) );
456	}
457	}
458
459	void __ioctx_prepare_block($io_ctx_thread & ctx, struct epoll_event & ev) {
460	int ret = epoll_ctl(iopoll.epollfd, EPOLL_CTL_MOD, ctx.ring->fd, &ev);
461	if (ret < 0) {
462	abort( "KERNEL ERROR: EPOLL REARM - (%d) %s\n", (int)errno, strerror(errno) );
463	}
464	}
465
466	//=============================================================================================
467	// I/O Context Misc Setup
468	//=============================================================================================
469	void register_fixed_files( io_context & ctx, int * files, unsigned count ) {
470	int ret = syscall( __NR_io_uring_register, ctx.thrd.ring->fd, IORING_REGISTER_FILES, files, count );
471	if( ret < 0 ) {
472	abort( "KERNEL ERROR: IO_URING SYSCALL - (%d) %s\n", (int)errno, strerror(errno) );
473	}
474
475	__cfadbg_print_safe( io_core, "Kernel I/O : Performed io_register for %p, returned %d\n", active_thread(), ret );
476	}
477
478	void register_fixed_files( cluster & cltr, int * files, unsigned count ) {
479	for(i; cltr.io.cnt) {
480	register_fixed_files( cltr.io.ctxs[i], files, count );
481	}
482	}
483	#endif

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