1206497Sluigi/*- 2206552Sluigi * Copyright (c) 2009-2010 Fabio Checconi 3206552Sluigi * Copyright (c) 2009-2010 Luigi Rizzo, Universita` di Pisa 4206497Sluigi * All rights reserved. 5206497Sluigi * 6206497Sluigi * Redistribution and use in source and binary forms, with or without 7206497Sluigi * modification, are permitted provided that the following conditions 8206497Sluigi * are met: 9206497Sluigi * 1. Redistributions of source code must retain the above copyright 10206497Sluigi * notice, this list of conditions and the following disclaimer. 11206497Sluigi * 2. Redistributions in binary form must reproduce the above copyright 12206497Sluigi * notice, this list of conditions and the following disclaimer in the 13206497Sluigi * documentation and/or other materials provided with the distribution. 14206497Sluigi * 15206497Sluigi * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 16206497Sluigi * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17206497Sluigi * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18206497Sluigi * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 19206497Sluigi * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20206497Sluigi * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21206497Sluigi * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22206497Sluigi * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23206497Sluigi * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24206497Sluigi * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25206497Sluigi * SUCH DAMAGE. 26206497Sluigi */ 27206497Sluigi 28206497Sluigi#ifndef _G_SCHED_H_ 29206497Sluigi#define _G_SCHED_H_ 30206497Sluigi 31206497Sluigi/* 32206497Sluigi * $Id$ 33206497Sluigi * $FreeBSD$ 34206497Sluigi * 35206497Sluigi * Header for the geom_sched class (userland library and kernel part). 36206497Sluigi * See g_sched.c for documentation. 37206497Sluigi * The userland code only needs the three G_SCHED_* values below. 38206497Sluigi */ 39206497Sluigi 40206497Sluigi#define G_SCHED_CLASS_NAME "SCHED" 41206497Sluigi#define G_SCHED_VERSION 0 42206497Sluigi#define G_SCHED_SUFFIX ".sched." 43206497Sluigi 44206497Sluigi#ifdef _KERNEL 45206497Sluigi#define G_SCHED_DEBUG(lvl, ...) do { \ 46206497Sluigi if (me.gs_debug >= (lvl)) { \ 47206497Sluigi printf("GEOM_SCHED"); \ 48206497Sluigi if (me.gs_debug > 0) \ 49206497Sluigi printf("[%u]", lvl); \ 50206497Sluigi printf(": "); \ 51206497Sluigi printf(__VA_ARGS__); \ 52206497Sluigi printf("\n"); \ 53206497Sluigi } \ 54206497Sluigi} while (0) 55206497Sluigi 56206497Sluigi#define G_SCHED_LOGREQ(bp, ...) do { \ 57206497Sluigi if (me.gs_debug >= 2) { \ 58206497Sluigi printf("GEOM_SCHED[2]: "); \ 59206497Sluigi printf(__VA_ARGS__); \ 60206497Sluigi printf(" "); \ 61206497Sluigi g_print_bio(bp); \ 62206497Sluigi printf("\n"); \ 63206497Sluigi } \ 64206497Sluigi} while (0) 65206497Sluigi 66206497SluigiLIST_HEAD(g_hash, g_sched_class); 67206497Sluigi 68206497Sluigi/* 69206497Sluigi * Descriptor of a scheduler. 70206497Sluigi * In addition to the obvious fields, sc_flushing and sc_pending 71206497Sluigi * support dynamic switching of scheduling algorithm. 72206497Sluigi * Normally, sc_flushing is 0, and requests that are scheduled are 73206497Sluigi * also added to the sc_pending queue, and removed when we receive 74206497Sluigi * the 'done' event. 75206497Sluigi * 76206497Sluigi * When we are transparently inserted on an existing provider, 77206497Sluigi * sc_proxying is set. The detach procedure is slightly different. 78206497Sluigi * 79206497Sluigi * When switching schedulers, sc_flushing is set so requests bypass us, 80206497Sluigi * and at the same time we update the pointer in the pending bios 81206497Sluigi * to ignore us when they return up. 82206497Sluigi * XXX it would be more efficient to implement sc_pending with 83206497Sluigi * a generation number: the softc generation is increased when 84206497Sluigi * we change scheduling algorithm, we store the current generation 85206497Sluigi * number in the pending bios, and when they come back we ignore 86206497Sluigi * the done() call if the generation number do not match. 87206497Sluigi */ 88206497Sluigistruct g_sched_softc { 89206497Sluigi /* 90206497Sluigi * Generic fields used by any scheduling algorithm: 91206497Sluigi * a mutex, the class descriptor, flags, list of pending 92206497Sluigi * requests (used when flushing the module) and support 93206497Sluigi * for hash tables where we store per-flow queues. 94206497Sluigi */ 95206497Sluigi struct mtx sc_mtx; 96206497Sluigi struct g_gsched *sc_gsched; /* Scheduler descriptor. */ 97206497Sluigi int sc_pending; /* Pending requests. */ 98206497Sluigi int sc_flags; /* Various flags. */ 99206497Sluigi 100206497Sluigi /* 101206497Sluigi * Hash tables to store per-flow queues are generally useful 102206497Sluigi * so we handle them in the common code. 103206497Sluigi * sc_hash and sc_mask are parameters of the hash table, 104206497Sluigi * the last two fields are used to periodically remove 105206497Sluigi * expired items from the hash table. 106206497Sluigi */ 107206497Sluigi struct g_hash *sc_hash; 108206497Sluigi u_long sc_mask; 109206497Sluigi int sc_flush_ticks; /* Next tick for a flush. */ 110206497Sluigi int sc_flush_bucket; /* Next bucket to flush. */ 111206497Sluigi 112206497Sluigi /* 113206497Sluigi * Pointer to the algorithm's private data, which is the value 114206497Sluigi * returned by sc_gsched->gs_init() . A NULL here means failure. 115206497Sluigi * XXX intptr_t might be more appropriate. 116206497Sluigi */ 117206497Sluigi void *sc_data; 118206497Sluigi}; 119206497Sluigi 120206497Sluigi#define G_SCHED_PROXYING 1 121206497Sluigi#define G_SCHED_FLUSHING 2 122206497Sluigi 123206497Sluigi/* 124206497Sluigi * Temporary- our own version of the disksort, because the 125206497Sluigi * version in 7.x and 8.x before march 2009 is buggy. 126206497Sluigi */ 127206497Sluigivoid gs_bioq_init(struct bio_queue_head *); 128206497Sluigivoid gs_bioq_remove(struct bio_queue_head *, struct bio *); 129206497Sluigivoid gs_bioq_flush(struct bio_queue_head *, struct devstat *, int); 130206497Sluigivoid gs_bioq_insert_head(struct bio_queue_head *, struct bio *); 131206497Sluigivoid gs_bioq_insert_tail(struct bio_queue_head *, struct bio *); 132206497Sluigistruct bio *gs_bioq_first(struct bio_queue_head *); 133206497Sluigistruct bio *gs_bioq_takefirst(struct bio_queue_head *); 134206497Sluigivoid gs_bioq_disksort(struct bio_queue_head *, struct bio *); 135206497Sluigi 136206497Sluigi#endif /* _KERNEL */ 137206497Sluigi 138206497Sluigi#endif /* _G_SCHED_H_ */ 139