gdb/osf-share/cma_sched.h

   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