1 /* 2 * Copyright (c) 2008 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * $DragonFly: src/sys/kern/kern_iosched.c,v 1.1 2008/06/28 17:59:49 dillon Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/kernel.h> 40 #include <sys/proc.h> 41 #include <sys/rtprio.h> 42 #include <sys/queue.h> 43 #include <machine/cpu.h> 44 #include <sys/spinlock.h> 45 #include <sys/iosched.h> 46 #include <sys/buf.h> 47 48 #include <sys/thread2.h> 49 #include <sys/spinlock2.h> 50 51 #include <vm/vm.h> 52 #include <vm/vm_param.h> 53 #include <vm/vm_kern.h> 54 #include <vm/vm_extern.h> 55 56 /* 57 * Caller intends to write (bytes) 58 */ 59 void 60 bwillwrite(int bytes) 61 { 62 int count; 63 64 count = bd_heatup(); 65 if (count > 0) 66 bd_wait(count / 2); 67 } 68 69 /* 70 * Caller intends to read (bytes) 71 */ 72 void 73 bwillread(int bytes) 74 { 75 } 76 77 /* 78 * Call intends to do an inode-modifying operation of some sort. 79 */ 80 void 81 bwillinode(int n) 82 { 83 int count; 84 85 count = bd_heatup(); 86 if (count > 0) 87 bd_wait(1); 88 } 89 90