197 lines
6.7 KiB
C
197 lines
6.7 KiB
C
/* This file contains the main program of the memory manager and some related
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* procedures. When MINIX starts up, the kernel runs for a little while,
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* initializing itself and its tasks, and then it runs MM and FS. Both MM
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* and FS initialize themselves as far as they can. FS then makes a call to
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* MM, because MM has to wait for FS to acquire a RAM disk. MM asks the
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* kernel for all free memory and starts serving requests.
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*
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* The entry points into this file are:
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* main: starts MM running
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* setreply: set the reply to be sent to process making an MM system call
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*/
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#include "mm.h"
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#include <minix/utils.h>
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#include <minix/callnr.h>
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#include <minix/com.h>
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#include <signal.h>
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#include <fcntl.h>
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#include <sys/ioc_memory.h>
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#include "mproc.h"
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#include "param.h"
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FORWARD _PROTOTYPE( void get_work, (void) );
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FORWARD _PROTOTYPE( void mm_init, (void) );
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#define click_to_round_k(n) \
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((unsigned) ((((unsigned long) (n) << CLICK_SHIFT) + 512) / 1024))
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/*===========================================================================*
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* main *
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*===========================================================================*/
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PUBLIC void main()
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{
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/* Main routine of the memory manager. */
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int result, proc_nr;
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struct mproc *rmp;
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mm_init(); /* initialize memory manager tables */
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/* This is MM's main loop- get work and do it, forever and forever. */
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while (TRUE) {
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get_work(); /* wait for an MM system call */
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/* Check for system notifications first. Special cases. */
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if (call_nr == HARD_STOP) { /* MINIX is shutting down */
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check_sig(-1, SIGKILL); /* kill all processes */
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sys_exit(0);
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/* never reached */
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} else if (call_nr == KSIG_PENDING) { /* signals pending */
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(void) ksig_pending();
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result = SUSPEND; /* don't reply */
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}
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/* Else, if the system call number is valid, perform the call. */
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else if ((unsigned) call_nr >= NCALLS) {
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result = ENOSYS;
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} else {
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result = (*call_vec[call_nr])();
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}
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/* Send the results back to the user to indicate completion. */
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if (result != SUSPEND) setreply(who, result);
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swap_in(); /* maybe a process can be swapped in? */
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/* Send out all pending reply messages, including the answer to
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* the call just made above. The processes must not be swapped out.
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*/
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for (proc_nr=0, rmp=mproc; proc_nr < NR_PROCS; proc_nr++, rmp++) {
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if ((rmp->mp_flags & (REPLY | ONSWAP)) == REPLY) {
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if (send(proc_nr, &rmp->mp_reply) != OK)
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panic("MM can't reply to", proc_nr);
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rmp->mp_flags &= ~REPLY;
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}
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}
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}
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}
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/*===========================================================================*
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* get_work *
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*===========================================================================*/
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PRIVATE void get_work()
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{
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/* Wait for the next message and extract useful information from it. */
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if (receive(ANY, &m_in) != OK) panic("MM receive error", NO_NUM);
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who = m_in.m_source; /* who sent the message */
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call_nr = m_in.m_type; /* system call number */
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/* Process slot of caller. Misuse MM's own process slot if the kernel is
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* calling. The can happen in case of pending kernel signals.
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*/
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mp = &mproc[who < 0 ? PM_PROC_NR : who];
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}
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/*===========================================================================*
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* setreply *
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*===========================================================================*/
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PUBLIC void setreply(proc_nr, result)
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int proc_nr; /* process to reply to */
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int result; /* result of the call (usually OK or error #)*/
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{
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/* Fill in a reply message to be sent later to a user process. System calls
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* may occasionally fill in other fields, this is only for the main return
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* value, and for setting the "must send reply" flag.
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*/
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register struct mproc *rmp = &mproc[proc_nr];
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rmp->mp_reply.reply_res = result;
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rmp->mp_flags |= REPLY; /* reply pending */
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if (rmp->mp_flags & ONSWAP)
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swap_inqueue(rmp); /* must swap this process back in */
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}
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/*===========================================================================*
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* mm_init *
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*===========================================================================*/
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PRIVATE void mm_init()
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{
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/* Initialize the memory manager. */
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int s;
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static char core_sigs[] = { SIGQUIT, SIGILL, SIGTRAP, SIGABRT,
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SIGEMT, SIGFPE, SIGUSR1, SIGSEGV, SIGUSR2 };
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static char ign_sigs[] = { SIGCHLD };
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register int proc_nr;
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register struct mproc *rmp;
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register char *sig_ptr;
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phys_clicks ram_clicks, total_clicks, minix_clicks, free_clicks;
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message mess;
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struct mem_map kernel_map[NR_LOCAL_SEGS];
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int mem;
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/* Build the set of signals which cause core dumps, and the set of signals
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* that are by default ignored.
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*/
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sigemptyset(&core_sset);
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for (sig_ptr = core_sigs; sig_ptr < core_sigs+sizeof(core_sigs); sig_ptr++)
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sigaddset(&core_sset, *sig_ptr);
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sigemptyset(&ign_sset);
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for (sig_ptr = ign_sigs; sig_ptr < ign_sigs+sizeof(ign_sigs); sig_ptr++)
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sigaddset(&ign_sset, *sig_ptr);
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/* Get the memory map of the kernel to see how much memory it uses. */
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if ((s=p_getmap(SYSTASK, kernel_map)) != OK)
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panic("MM couldn't get proc entry of SYSTASK",s);
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minix_clicks = (kernel_map[S].mem_phys + kernel_map[S].mem_len)
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- kernel_map[T].mem_phys;
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/* Initialize MM's tables. Request a copy of the system image table that
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* is defined at the kernel level to see which slots to fill in.
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*/
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for (proc_nr = 0; proc_nr <= INIT_PROC_NR; proc_nr++) {
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rmp = &mproc[proc_nr];
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rmp->mp_flags |= IN_USE;
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if ((s=p_getmap(proc_nr, rmp->mp_seg)) != OK)
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panic("MM couldn't get proc entry",s);
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if (rmp->mp_seg[T].mem_len != 0) rmp->mp_flags |= SEPARATE;
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minix_clicks += (rmp->mp_seg[S].mem_phys + rmp->mp_seg[S].mem_len)
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- rmp->mp_seg[T].mem_phys;
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}
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mproc[INIT_PROC_NR].mp_pid = INIT_PID;
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sigemptyset(&mproc[INIT_PROC_NR].mp_ignore);
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sigemptyset(&mproc[INIT_PROC_NR].mp_catch);
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procs_in_use = LOW_USER + 1;
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/* Wait for FS to send a message telling the RAM disk size then go "on-line".
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*/
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if (receive(FS_PROC_NR, &mess) != OK)
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panic("MM can't obtain RAM disk size from FS", NO_NUM);
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ram_clicks = mess.MEM_CHUNK_SIZE;
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/* Initialize tables to all physical mem. */
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mem_init(&free_clicks);
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total_clicks = minix_clicks + ram_clicks + free_clicks;
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/* Print memory information. */
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printf("Memory size=%uK ", click_to_round_k(total_clicks));
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printf("MINIX=%uK ", click_to_round_k(minix_clicks));
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printf("RAM disk=%uK ", click_to_round_k(ram_clicks));
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printf("Available=%uK\n\n", click_to_round_k(free_clicks));
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/* Tell FS to continue. */
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if (send(FS_PROC_NR, &mess) != OK)
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panic("MM can't sync up with FS", NO_NUM);
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/* Tell the memory task where my process table is for the sake of ps(1). */
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if ((mem = open("/dev/ram", O_RDWR)) != -1) {
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ioctl(mem, MIOCSPSINFO, (void *) mproc);
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close(mem);
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}
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}
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