minix/servers/pm/main.c

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