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/* $MidnightBSD$ */ |
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/*- |
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* Copyright (c) 2009-2010 Fabio Checconi |
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* Copyright (c) 2009-2010 Luigi Rizzo, Universita` di Pisa |
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* All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND |
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE |
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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*/ |
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|
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#ifndef _G_SCHED_H_ |
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#define _G_SCHED_H_ |
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|
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/* |
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* $Id$ |
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* $FreeBSD: stable/10/sys/geom/sched/g_sched.h 206552 2010-04-13 09:56:17Z luigi $ |
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* |
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* Header for the geom_sched class (userland library and kernel part). |
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* See g_sched.c for documentation. |
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* The userland code only needs the three G_SCHED_* values below. |
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*/ |
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|
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#define G_SCHED_CLASS_NAME "SCHED" |
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#define G_SCHED_VERSION 0 |
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#define G_SCHED_SUFFIX ".sched." |
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|
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#ifdef _KERNEL |
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#define G_SCHED_DEBUG(lvl, ...) do { \ |
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if (me.gs_debug >= (lvl)) { \ |
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printf("GEOM_SCHED"); \ |
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if (me.gs_debug > 0) \ |
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printf("[%u]", lvl); \ |
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printf(": "); \ |
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printf(__VA_ARGS__); \ |
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printf("\n"); \ |
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} \ |
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} while (0) |
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|
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#define G_SCHED_LOGREQ(bp, ...) do { \ |
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if (me.gs_debug >= 2) { \ |
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printf("GEOM_SCHED[2]: "); \ |
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printf(__VA_ARGS__); \ |
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printf(" "); \ |
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g_print_bio(bp); \ |
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printf("\n"); \ |
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} \ |
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} while (0) |
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|
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LIST_HEAD(g_hash, g_sched_class); |
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|
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/* |
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* Descriptor of a scheduler. |
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* In addition to the obvious fields, sc_flushing and sc_pending |
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* support dynamic switching of scheduling algorithm. |
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* Normally, sc_flushing is 0, and requests that are scheduled are |
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* also added to the sc_pending queue, and removed when we receive |
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* the 'done' event. |
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* |
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* When we are transparently inserted on an existing provider, |
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* sc_proxying is set. The detach procedure is slightly different. |
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* |
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* When switching schedulers, sc_flushing is set so requests bypass us, |
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* and at the same time we update the pointer in the pending bios |
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* to ignore us when they return up. |
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* XXX it would be more efficient to implement sc_pending with |
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* a generation number: the softc generation is increased when |
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* we change scheduling algorithm, we store the current generation |
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* number in the pending bios, and when they come back we ignore |
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* the done() call if the generation number do not match. |
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*/ |
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struct g_sched_softc { |
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/* |
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* Generic fields used by any scheduling algorithm: |
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* a mutex, the class descriptor, flags, list of pending |
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* requests (used when flushing the module) and support |
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* for hash tables where we store per-flow queues. |
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*/ |
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struct mtx sc_mtx; |
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struct g_gsched *sc_gsched; /* Scheduler descriptor. */ |
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int sc_pending; /* Pending requests. */ |
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int sc_flags; /* Various flags. */ |
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|
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/* |
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* Hash tables to store per-flow queues are generally useful |
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* so we handle them in the common code. |
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* sc_hash and sc_mask are parameters of the hash table, |
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* the last two fields are used to periodically remove |
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* expired items from the hash table. |
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*/ |
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struct g_hash *sc_hash; |
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u_long sc_mask; |
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int sc_flush_ticks; /* Next tick for a flush. */ |
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int sc_flush_bucket; /* Next bucket to flush. */ |
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|
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/* |
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* Pointer to the algorithm's private data, which is the value |
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* returned by sc_gsched->gs_init() . A NULL here means failure. |
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* XXX intptr_t might be more appropriate. |
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*/ |
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void *sc_data; |
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}; |
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|
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#define G_SCHED_PROXYING 1 |
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#define G_SCHED_FLUSHING 2 |
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|
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/* |
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* Temporary- our own version of the disksort, because the |
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* version in 7.x and 8.x before march 2009 is buggy. |
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*/ |
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void gs_bioq_init(struct bio_queue_head *); |
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void gs_bioq_remove(struct bio_queue_head *, struct bio *); |
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void gs_bioq_flush(struct bio_queue_head *, struct devstat *, int); |
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void gs_bioq_insert_head(struct bio_queue_head *, struct bio *); |
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void gs_bioq_insert_tail(struct bio_queue_head *, struct bio *); |
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struct bio *gs_bioq_first(struct bio_queue_head *); |
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struct bio *gs_bioq_takefirst(struct bio_queue_head *); |
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void gs_bioq_disksort(struct bio_queue_head *, struct bio *); |
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|
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#endif /* _KERNEL */ |
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|
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#endif /* _G_SCHED_H_ */ |
