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c906108c SS |
1 | /* |
2 | * (c) Copyright 1990-1996 OPEN SOFTWARE FOUNDATION, INC. | |
3 | * (c) Copyright 1990-1996 HEWLETT-PACKARD COMPANY | |
4 | * (c) Copyright 1990-1996 DIGITAL EQUIPMENT CORPORATION | |
5 | * (c) Copyright 1991, 1992 Siemens-Nixdorf Information Systems | |
6 | * To anyone who acknowledges that this file is provided "AS IS" without | |
7 | * any express or implied warranty: permission to use, copy, modify, and | |
8 | * distribute this file for any purpose is hereby granted without fee, | |
9 | * provided that the above copyright notices and this notice appears in | |
10 | * all source code copies, and that none of the names listed above be used | |
11 | * in advertising or publicity pertaining to distribution of the software | |
12 | * without specific, written prior permission. None of these organizations | |
13 | * makes any representations about the suitability of this software for | |
14 | * any purpose. | |
15 | */ | |
16 | /* | |
17 | * Header file for priority scheduling | |
18 | */ | |
19 | ||
20 | \f | |
21 | #ifndef CMA_SCHED | |
22 | #define CMA_SCHED | |
23 | ||
24 | /* | |
25 | * INCLUDE FILES | |
26 | */ | |
27 | ||
28 | /* | |
29 | * CONSTANTS AND MACROS | |
30 | */ | |
31 | ||
32 | /* | |
33 | * Scaling factor for integer priority calculations | |
34 | */ | |
35 | #define cma__c_prio_scale 8 | |
36 | ||
37 | #if _CMA_VENDOR_ == _CMA__APOLLO | |
38 | /* | |
39 | * FIX-ME: Apollo cc 6.8 blows contant folded "<<" and ">>" | |
40 | */ | |
41 | # define cma__scale_up(exp) ((exp) * 256) | |
42 | # define cma__scale_dn(exp) ((exp) / 256) | |
43 | #else | |
44 | # define cma__scale_up(exp) ((exp) << cma__c_prio_scale) | |
45 | # define cma__scale_dn(exp) ((exp) >> cma__c_prio_scale) | |
46 | #endif | |
47 | ||
48 | ||
49 | /* | |
50 | * Min. num. of ticks between self-adjustments for priority adjusting policies. | |
51 | */ | |
52 | #define cma__c_prio_interval 10 | |
53 | ||
54 | ||
55 | /* | |
56 | * Number of queues in each class of queues | |
57 | */ | |
58 | #define cma__c_prio_n_id 1 /* Very-low-priority class threads */ | |
59 | #define cma__c_prio_n_bg 8 /* Background class threads */ | |
60 | #define cma__c_prio_n_0 1 /* Very low priority throughput quartile */ | |
61 | #define cma__c_prio_n_1 2 /* Low priority throughput quartile */ | |
62 | #define cma__c_prio_n_2 3 /* Medium priority throughput quartile */ | |
63 | #define cma__c_prio_n_3 4 /* High priority throughput quartile */ | |
64 | #define cma__c_prio_n_rt 1 /* Real Time priority queues */ | |
65 | ||
66 | /* | |
67 | * Number of queues to skip (offset) to get to the queues in this section of LA | |
68 | */ | |
69 | #define cma__c_prio_o_id 0 | |
70 | #define cma__c_prio_o_bg cma__c_prio_o_id + cma__c_prio_n_id | |
71 | #define cma__c_prio_o_0 cma__c_prio_o_bg + cma__c_prio_n_bg | |
72 | #define cma__c_prio_o_1 cma__c_prio_o_0 + cma__c_prio_n_0 | |
73 | #define cma__c_prio_o_2 cma__c_prio_o_1 + cma__c_prio_n_1 | |
74 | #define cma__c_prio_o_3 cma__c_prio_o_2 + cma__c_prio_n_2 | |
75 | #define cma__c_prio_o_rt cma__c_prio_o_3 + cma__c_prio_n_3 | |
76 | ||
77 | /* | |
78 | * Ada_low: These threads are queued in the background queues, thus there | |
79 | * must be enough queues to allow one queue for each Ada priority below the | |
80 | * Ada default. | |
81 | */ | |
82 | #define cma__c_prio_o_al cma__c_prio_o_bg | |
83 | ||
84 | /* | |
85 | * Total number of ready queues, for declaration purposes | |
86 | */ | |
87 | #define cma__c_prio_n_tot \ | |
88 | cma__c_prio_n_id + cma__c_prio_n_bg + cma__c_prio_n_rt \ | |
89 | + cma__c_prio_n_0 + cma__c_prio_n_1 + cma__c_prio_n_2 + cma__c_prio_n_3 | |
90 | ||
91 | /* | |
92 | * Formulae for determining a thread's priority. Variable priorities (such | |
93 | * as foreground and background) are scaled values. | |
94 | */ | |
95 | #define cma__sched_priority(tcb) \ | |
96 | ((tcb)->sched.class == cma__c_class_fore ? cma__sched_prio_fore (tcb) \ | |
97 | :((tcb)->sched.class == cma__c_class_back ? cma__sched_prio_back (tcb) \ | |
98 | :((tcb)->sched.class == cma__c_class_rt ? cma__sched_prio_rt (tcb) \ | |
99 | :((tcb)->sched.class == cma__c_class_idle ? cma__sched_prio_idle (tcb) \ | |
100 | :(cma__bugcheck ("cma__sched_priority: unrecognized class"), 0) )))) | |
101 | ||
102 | #define cma__sched_prio_fore(tcb) cma__sched_prio_fore_var (tcb) | |
103 | #define cma__sched_prio_back(tcb) ((tcb)->sched.fixed_prio \ | |
104 | ? cma__sched_prio_back_fix (tcb) : cma__sched_prio_back_var (tcb) ) | |
105 | #define cma__sched_prio_rt(tcb) ((tcb)->sched.priority) | |
106 | #define cma__sched_prio_idle(tcb) ((tcb)->sched.priority) | |
107 | ||
108 | #define cma__sched_prio_back_fix(tcb) \ | |
109 | (cma__g_prio_bg_min + (cma__g_prio_bg_max - cma__g_prio_bg_min) \ | |
110 | * ((tcb)->sched.priority + cma__c_prio_o_al - cma__c_prio_o_bg) \ | |
111 | / cma__c_prio_n_bg) | |
112 | ||
113 | /* | |
114 | * FIX-ME: Enable after modeling (if we like it) | |
115 | */ | |
116 | #if 1 | |
117 | # define cma__sched_prio_fore_var(tcb) \ | |
118 | ((cma__g_prio_fg_max + cma__g_prio_fg_min)/2) | |
119 | # define cma__sched_prio_back_var(tcb) \ | |
120 | ((cma__g_prio_bg_max + cma__g_prio_bg_min)/2) | |
121 | #else | |
122 | # define cma__sched_prio_back_var(tcb) cma__sched_prio_fore_var (tcb) | |
123 | ||
124 | # if 1 | |
125 | /* | |
126 | * Re-scale, since the division removes the scale factor. | |
127 | * Scale and multiply before dividing to avoid loss of precision. | |
128 | */ | |
129 | # define cma__sched_prio_fore_var(tcb) \ | |
130 | ((cma__g_vp_count * cma__scale_up((tcb)->sched.tot_time)) \ | |
131 | / (tcb)->sched.cpu_time) | |
132 | # else | |
133 | /* | |
134 | * Re-scale, since the division removes the scale factor. | |
135 | * Scale and multiply before dividing to avoid loss of precision. | |
136 | * Left shift the numerator to multiply by two. | |
137 | */ | |
138 | # define cma__sched_prio_fore_var(tcb) \ | |
139 | (((cma__g_vp_count * cma__scale_up((tcb)->sched.tot_time) \ | |
140 | * (tcb)->sched.priority * cma__g_init_frac_sum) << 1) \ | |
141 | / ((tcb)->sched.cpu_time * (tcb)->sched.priority * cma__g_init_frac_sum \ | |
142 | + (tcb)->sched.tot_time)) | |
143 | # endif | |
144 | #endif | |
145 | ||
146 | /* | |
147 | * Update weighted-averaged, scaled tick counters | |
148 | */ | |
149 | #define cma__sched_update_time(ave, new) \ | |
150 | (ave) = (ave) - ((cma__scale_dn((ave)) - (new)) << (cma__c_prio_scale - 4)) | |
151 | ||
152 | #define cma__sched_parameterize(tcb, policy) { \ | |
153 | switch (policy) { \ | |
154 | case cma_c_sched_fifo : { \ | |
155 | (tcb)->sched.rtb = cma_c_true; \ | |
156 | (tcb)->sched.spp = cma_c_true; \ | |
157 | (tcb)->sched.fixed_prio = cma_c_true; \ | |
158 | (tcb)->sched.class = cma__c_class_rt; \ | |
159 | break; \ | |
160 | } \ | |
161 | case cma_c_sched_rr : { \ | |
162 | (tcb)->sched.rtb = cma_c_false; \ | |
163 | (tcb)->sched.spp = cma_c_true; \ | |
164 | (tcb)->sched.fixed_prio = cma_c_true; \ | |
165 | (tcb)->sched.class = cma__c_class_rt; \ | |
166 | break; \ | |
167 | } \ | |
168 | case cma_c_sched_throughput : { \ | |
169 | (tcb)->sched.rtb = cma_c_false; \ | |
170 | (tcb)->sched.spp = cma_c_false; \ | |
171 | (tcb)->sched.fixed_prio = cma_c_false; \ | |
172 | (tcb)->sched.class = cma__c_class_fore; \ | |
173 | break; \ | |
174 | } \ | |
175 | case cma_c_sched_background : { \ | |
176 | (tcb)->sched.rtb = cma_c_false; \ | |
177 | (tcb)->sched.spp = cma_c_false; \ | |
178 | (tcb)->sched.fixed_prio = cma_c_false; \ | |
179 | (tcb)->sched.class = cma__c_class_back; \ | |
180 | break; \ | |
181 | } \ | |
182 | case cma_c_sched_ada_low : { \ | |
183 | (tcb)->sched.rtb = cma_c_false; \ | |
184 | (tcb)->sched.spp = cma_c_true; \ | |
185 | (tcb)->sched.fixed_prio = cma_c_true; \ | |
186 | (tcb)->sched.class = cma__c_class_back; \ | |
187 | break; \ | |
188 | } \ | |
189 | case cma_c_sched_idle : { \ | |
190 | (tcb)->sched.rtb = cma_c_false; \ | |
191 | (tcb)->sched.spp = cma_c_false; \ | |
192 | (tcb)->sched.fixed_prio = cma_c_false; \ | |
193 | (tcb)->sched.class = cma__c_class_idle; \ | |
194 | break; \ | |
195 | } \ | |
196 | default : { \ | |
197 | cma__bugcheck ("cma__sched_parameterize: bad scheduling Policy"); \ | |
198 | break; \ | |
199 | } \ | |
200 | } \ | |
201 | } | |
202 | ||
203 | /* | |
204 | * TYPEDEFS | |
205 | */ | |
206 | ||
207 | /* | |
208 | * Scheduling classes | |
209 | */ | |
210 | typedef enum CMA__T_SCHED_CLASS { | |
211 | cma__c_class_rt, | |
212 | cma__c_class_fore, | |
213 | cma__c_class_back, | |
214 | cma__c_class_idle | |
215 | } cma__t_sched_class; | |
216 | ||
217 | /* | |
218 | * GLOBAL DATA | |
219 | */ | |
220 | ||
221 | /* | |
222 | * Minimuma and maximum prioirities, for foreground and background threads, | |
223 | * as of the last time the scheduler ran. (Scaled once.) | |
224 | */ | |
225 | extern cma_t_integer cma__g_prio_fg_min; | |
226 | extern cma_t_integer cma__g_prio_fg_max; | |
227 | extern cma_t_integer cma__g_prio_bg_min; | |
228 | extern cma_t_integer cma__g_prio_bg_max; | |
229 | ||
230 | /* | |
231 | * The "m" values are the slopes of the four sections of linear approximation. | |
232 | * | |
233 | * cma__g_prio_m_I = 4*N(I)/cma__g_prio_range (Scaled once.) | |
234 | */ | |
235 | extern cma_t_integer cma__g_prio_m_0, | |
236 | cma__g_prio_m_1, | |
237 | cma__g_prio_m_2, | |
238 | cma__g_prio_m_3; | |
239 | ||
240 | /* | |
241 | * The "b" values are the intercepts of the four sections of linear approx. | |
242 | * (Not scaled.) | |
243 | * | |
244 | * cma__g_prio_b_I = -N(I)*(I*prio_max + (4-I)*prio_min)/prio_range + prio_o_I | |
245 | */ | |
246 | extern cma_t_integer cma__g_prio_b_0, | |
247 | cma__g_prio_b_1, | |
248 | cma__g_prio_b_2, | |
249 | cma__g_prio_b_3; | |
250 | ||
251 | /* | |
252 | * The "p" values are the end points of the four sections of linear approx. | |
253 | * | |
254 | * cma__g_prio_p_I = cma__g_prio_fg_min + (I/4)*cma__g_prio_range | |
255 | * | |
256 | * [cma__g_prio_p_0 is not defined since it is not used (also, it is the same | |
257 | * as cma__g_prio_fg_min).] (Scaled once.) | |
258 | */ | |
259 | extern cma_t_integer cma__g_prio_p_1, | |
260 | cma__g_prio_p_2, | |
261 | cma__g_prio_p_3; | |
262 | ||
263 | /* | |
264 | * Points to the next queue for the dispatcher to check for ready threads. | |
265 | */ | |
266 | extern cma_t_integer cma__g_next_ready_queue; | |
267 | ||
268 | /* | |
269 | * Points to the queues of virtual processors (for preempt victim search) | |
270 | */ | |
271 | extern cma__t_queue cma__g_run_vps; | |
272 | extern cma__t_queue cma__g_susp_vps; | |
273 | extern cma_t_integer cma__g_vp_count; | |
274 | ||
275 | /* | |
276 | * INTERNAL INTERFACES | |
277 | */ | |
278 | ||
279 | #endif |