| subr_disk.c (103675) | subr_disk.c (103683) |
|---|---|
| 1/* 2 * ---------------------------------------------------------------------------- 3 * "THE BEER-WARE LICENSE" (Revision 42): 4 * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you 5 * can do whatever you want with this stuff. If we meet some day, and you think 6 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 7 * ---------------------------------------------------------------------------- 8 * | 1/* 2 * ---------------------------------------------------------------------------- 3 * "THE BEER-WARE LICENSE" (Revision 42): 4 * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you 5 * can do whatever you want with this stuff. If we meet some day, and you think 6 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 7 * ---------------------------------------------------------------------------- 8 * |
| 9 * $FreeBSD: head/sys/kern/subr_disk.c 103675 2002-09-20 12:52:03Z phk $ | 9 * $FreeBSD: head/sys/kern/subr_disk.c 103683 2002-09-20 14:14:37Z phk $ |
| 10 * 11 */ 12 13#include "opt_geom.h" 14 15#include <sys/param.h> 16#include <sys/systm.h> 17#include <sys/stdint.h> --- 446 unchanged lines hidden (view full) --- 464 sn += blkdone; 465 printf("fsbn %jd of ", (intmax_t)sn); 466 } 467 printf("%jd-%jd", (intmax_t)bp->bio_blkno, 468 (intmax_t)(bp->bio_blkno + (bp->bio_bcount - 1) / DEV_BSIZE)); 469 if (nl) 470 printf("\n"); 471} | 10 * 11 */ 12 13#include "opt_geom.h" 14 15#include <sys/param.h> 16#include <sys/systm.h> 17#include <sys/stdint.h> --- 446 unchanged lines hidden (view full) --- 464 sn += blkdone; 465 printf("fsbn %jd of ", (intmax_t)sn); 466 } 467 printf("%jd-%jd", (intmax_t)bp->bio_blkno, 468 (intmax_t)(bp->bio_blkno + (bp->bio_bcount - 1) / DEV_BSIZE)); 469 if (nl) 470 printf("\n"); 471} |
| 472 473#ifdef notquite 474/* 475 * Mutex to use when delaying niced I/O bound processes in bioq_disksort(). 476 */ 477static struct mtx dksort_mtx; 478static void 479dksort_init(void) 480{ 481 482 mtx_init(&dksort_mtx, "dksort", NULL, MTX_DEF); 483} 484SYSINIT(dksort, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, dksort_init, NULL) 485#endif 486 487/* 488 * Seek sort for disks. 489 * 490 * The buf_queue keep two queues, sorted in ascending block order. The first 491 * queue holds those requests which are positioned after the current block 492 * (in the first request); the second, which starts at queue->switch_point, 493 * holds requests which came in after their block number was passed. Thus 494 * we implement a one way scan, retracting after reaching the end of the drive 495 * to the first request on the second queue, at which time it becomes the 496 * first queue. 497 * 498 * A one-way scan is natural because of the way UNIX read-ahead blocks are 499 * allocated. 500 */ 501 502void 503bioq_disksort(bioq, bp) 504 struct bio_queue_head *bioq; 505 struct bio *bp; 506{ 507 struct bio *bq; 508 struct bio *bn; 509 struct bio *be; 510 511#ifdef notquite 512 struct thread *td = curthread; 513 514 if (td && td->td_ksegrp->kg_nice > 0) { 515 TAILQ_FOREACH(bn, &bioq->queue, bio_queue) 516 if (BIOTOBUF(bp)->b_vp != BIOTOBUF(bn)->b_vp) 517 break; 518 if (bn != NULL) { 519 mtx_lock(&dksort_mtx); 520 msleep(&dksort_mtx, &dksort_mtx, 521 PPAUSE | PCATCH | PDROP, "ioslow", 522 td->td_ksegrp->kg_nice); 523 } 524 } 525#endif 526 if (!atomic_cmpset_int(&bioq->busy, 0, 1)) 527 panic("Recursing in bioq_disksort()"); 528 be = TAILQ_LAST(&bioq->queue, bio_queue); 529 /* 530 * If the queue is empty or we are an 531 * ordered transaction, then it's easy. 532 */ 533 if ((bq = bioq_first(bioq)) == NULL) { 534 bioq_insert_tail(bioq, bp); 535 bioq->busy = 0; 536 return; 537 } else if (bioq->insert_point != NULL) { 538 539 /* 540 * A certain portion of the list is 541 * "locked" to preserve ordering, so 542 * we can only insert after the insert 543 * point. 544 */ 545 bq = bioq->insert_point; 546 } else { 547 548 /* 549 * If we lie before the last removed (currently active) 550 * request, and are not inserting ourselves into the 551 * "locked" portion of the list, then we must add ourselves 552 * to the second request list. 553 */ 554 if (bp->bio_pblkno < bioq->last_pblkno) { 555 556 bq = bioq->switch_point; 557 /* 558 * If we are starting a new secondary list, 559 * then it's easy. 560 */ 561 if (bq == NULL) { 562 bioq->switch_point = bp; 563 bioq_insert_tail(bioq, bp); 564 bioq->busy = 0; 565 return; 566 } 567 /* 568 * If we lie ahead of the current switch point, 569 * insert us before the switch point and move 570 * the switch point. 571 */ 572 if (bp->bio_pblkno < bq->bio_pblkno) { 573 bioq->switch_point = bp; 574 TAILQ_INSERT_BEFORE(bq, bp, bio_queue); 575 bioq->busy = 0; 576 return; 577 } 578 } else { 579 if (bioq->switch_point != NULL) 580 be = TAILQ_PREV(bioq->switch_point, 581 bio_queue, bio_queue); 582 /* 583 * If we lie between last_pblkno and bq, 584 * insert before bq. 585 */ 586 if (bp->bio_pblkno < bq->bio_pblkno) { 587 TAILQ_INSERT_BEFORE(bq, bp, bio_queue); 588 bioq->busy = 0; 589 return; 590 } 591 } 592 } 593 594 /* 595 * Request is at/after our current position in the list. 596 * Optimize for sequential I/O by seeing if we go at the tail. 597 */ 598 if (bp->bio_pblkno > be->bio_pblkno) { 599 TAILQ_INSERT_AFTER(&bioq->queue, be, bp, bio_queue); 600 bioq->busy = 0; 601 return; 602 } 603 604 /* Otherwise, insertion sort */ 605 while ((bn = TAILQ_NEXT(bq, bio_queue)) != NULL) { 606 607 /* 608 * We want to go after the current request if it is the end 609 * of the first request list, or if the next request is a 610 * larger cylinder than our request. 611 */ 612 if (bn == bioq->switch_point 613 || bp->bio_pblkno < bn->bio_pblkno) 614 break; 615 bq = bn; 616 } 617 TAILQ_INSERT_AFTER(&bioq->queue, bq, bp, bio_queue); 618 bioq->busy = 0; 619} 620 621 |
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