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minix/servers/pm/main.c
Jorrit Herder 021e3234d8 Jorrit's ... "progress?"
2006-03-10 16:10:05 +00:00

471 lines
17 KiB
C
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/* This file contains the main program of the process 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 PM and FS. Both PM
* and FS initialize themselves as far as they can. PM asks the kernel for
* all free memory and starts serving requests.
*
* The entry points into this file are:
* main: starts PM running
* setreply: set the reply to be sent to process making an PM system call
*/
#include "pm.h"
#include <minix/keymap.h>
#include <minix/callnr.h>
#include <minix/com.h>
#include <minix/endpoint.h>
#include <signal.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/resource.h>
#include <string.h>
#include "mproc.h"
#include "param.h"
#include "../../kernel/const.h"
#include "../../kernel/config.h"
#include "../../kernel/type.h"
#include "../../kernel/proc.h"
FORWARD _PROTOTYPE( void get_work, (void) );
FORWARD _PROTOTYPE( void pm_init, (void) );
FORWARD _PROTOTYPE( int get_nice_value, (int queue) );
FORWARD _PROTOTYPE( void get_mem_chunks, (struct memory *mem_chunks) );
FORWARD _PROTOTYPE( void patch_mem_chunks, (struct memory *mem_chunks,
struct mem_map *map_ptr) );
FORWARD _PROTOTYPE( void do_x86_vm, (struct memory mem_chunks[NR_MEMS]) );
#define click_to_round_k(n) \
((unsigned) ((((unsigned long) (n) << CLICK_SHIFT) + 512) / 1024))
/*===========================================================================*
* main *
*===========================================================================*/
PUBLIC int main()
{
/* Main routine of the process manager. */
int result, s, proc_nr;
struct mproc *rmp;
sigset_t sigset;
pm_init(); /* initialize process manager tables */
/* This is PM's main loop- get work and do it, forever and forever. */
while (TRUE) {
get_work(); /* wait for an PM system call */
/* Check for system notifications first. Special cases. */
if (call_nr == SYN_ALARM) {
pm_expire_timers(m_in.NOTIFY_TIMESTAMP);
result = SUSPEND; /* don't reply */
} else if (call_nr == SYS_SIG) { /* signals pending */
sigset = m_in.NOTIFY_ARG;
if (sigismember(&sigset, SIGKSIG)) {
(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_p, 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++) {
/* In the meantime, the process may have been killed by a
* signal (e.g. if a lethal pending signal was unblocked)
* without the PM realizing it. If the slot is no longer in
* use or just a zombie, don't try to reply.
*/
if ((rmp->mp_flags & (REPLY | ONSWAP | IN_USE | ZOMBIE)) ==
(REPLY | IN_USE)) {
if ((s=send(rmp->mp_endpoint, &rmp->mp_reply)) != OK) {
panic(__FILE__,"PM can't reply to",
rmp->mp_endpoint);
}
rmp->mp_flags &= ~REPLY;
}
}
}
return(OK);
}
/*===========================================================================*
* get_work *
*===========================================================================*/
PRIVATE void get_work()
{
/* Wait for the next message and extract useful information from it. */
if (receive(ANY, &m_in) != OK)
panic(__FILE__,"PM receive error", NO_NUM);
who_e = m_in.m_source; /* who sent the message */
if(pm_isokendpt(who_e, &who_p) != OK)
panic(__FILE__, "PM got message from invalid endpoint", who_e);
call_nr = m_in.m_type; /* system call number */
/* Process slot of caller. Misuse PM's own process slot if the kernel is
* calling. This can happen in case of synchronous alarms (CLOCK) or or
* event like pending kernel signals (SYSTEM).
*/
mp = &mproc[who_p < 0 ? PM_PROC_NR : who_p];
if(who_p >= 0 && mp->mp_endpoint != who_e) {
panic(__FILE__, "PM endpoint number out of sync with source",
mp->mp_endpoint);
}
}
/*===========================================================================*
* setreply *
*===========================================================================*/
PUBLIC void setreply(proc_nr, result)
int proc_nr; /* process to reply to */
int result; /* result of 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];
if(proc_nr < 0 || proc_nr >= NR_PROCS)
panic(__FILE__,"setreply arg out of range", 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 */
}
/*===========================================================================*
* pm_init *
*===========================================================================*/
PRIVATE void pm_init()
{
/* Initialize the process manager.
* Memory use info is collected from the boot monitor, the kernel, and
* all processes compiled into the system image. Initially this information
* is put into an array mem_chunks. Elements of mem_chunks are struct memory,
* and hold base, size pairs in units of clicks. This array is small, there
* should be no more than 8 chunks. After the array of chunks has been built
* the contents are used to initialize the hole list. Space for the hole list
* is reserved as an array with twice as many elements as the maximum number
* of processes allowed. It is managed as a linked list, and elements of the
* array are struct hole, which, in addition to storage for a base and size in
* click units also contain space for a link, a pointer to another element.
*/
int s;
static struct boot_image image[NR_BOOT_PROCS];
register struct boot_image *ip;
static char core_sigs[] = { SIGQUIT, SIGILL, SIGTRAP, SIGABRT,
SIGEMT, SIGFPE, SIGUSR1, SIGSEGV, SIGUSR2 };
static char ign_sigs[] = { SIGCHLD, SIGWINCH, SIGCONT };
static char mess_sigs[] = { SIGTERM, SIGHUP, SIGABRT, SIGQUIT };
register struct mproc *rmp;
register int i;
register char *sig_ptr;
phys_clicks total_clicks, minix_clicks, free_clicks;
message mess;
struct mem_map mem_map[NR_LOCAL_SEGS];
struct memory mem_chunks[NR_MEMS];
/* Initialize process table, including timers. */
for (rmp=&mproc[0]; rmp<&mproc[NR_PROCS]; rmp++) {
tmr_inittimer(&rmp->mp_timer);
}
/* 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);
/* Obtain a copy of the boot monitor parameters and the kernel info struct.
* Parse the list of free memory chunks. This list is what the boot monitor
* reported, but it must be corrected for the kernel and system processes.
*/
if ((s=sys_getmonparams(monitor_params, sizeof(monitor_params))) != OK)
panic(__FILE__,"get monitor params failed",s);
get_mem_chunks(mem_chunks);
if ((s=sys_getkinfo(&kinfo)) != OK)
panic(__FILE__,"get kernel info failed",s);
/* Get the memory map of the kernel to see how much memory it uses. */
if ((s=get_mem_map(SYSTASK, mem_map)) != OK)
panic(__FILE__,"couldn't get memory map of SYSTASK",s);
minix_clicks = (mem_map[S].mem_phys+mem_map[S].mem_len)-mem_map[T].mem_phys;
patch_mem_chunks(mem_chunks, mem_map);
/* Initialize PM's process table. Request a copy of the system image table
* that is defined at the kernel level to see which slots to fill in.
*/
if (OK != (s=sys_getimage(image)))
panic(__FILE__,"couldn't get image table: %d\n", s);
procs_in_use = 0; /* start populating table */
printf("Building process table:"); /* show what's happening */
for (ip = &image[0]; ip < &image[NR_BOOT_PROCS]; ip++) {
if (ip->proc_nr >= 0) { /* task have negative nrs */
procs_in_use += 1; /* found user process */
/* Set process details found in the image table. */
rmp = &mproc[ip->proc_nr];
strncpy(rmp->mp_name, ip->proc_name, PROC_NAME_LEN);
rmp->mp_parent = RS_PROC_NR;
rmp->mp_nice = get_nice_value(ip->priority);
sigemptyset(&rmp->mp_sig2mess);
sigemptyset(&rmp->mp_ignore);
sigemptyset(&rmp->mp_sigmask);
sigemptyset(&rmp->mp_catch);
if (ip->proc_nr == INIT_PROC_NR) { /* user process */
rmp->mp_procgrp = rmp->mp_pid = INIT_PID;
rmp->mp_flags |= IN_USE;
}
else { /* system process */
rmp->mp_pid = get_free_pid();
rmp->mp_flags |= IN_USE | DONT_SWAP | PRIV_PROC;
for (sig_ptr = mess_sigs;
sig_ptr < mess_sigs+sizeof(mess_sigs);
sig_ptr++)
sigaddset(&rmp->mp_sig2mess, *sig_ptr);
}
/* Get kernel endpoint identifier. */
rmp->mp_endpoint = ip->endpoint;
/* Get memory map for this process from the kernel. */
if ((s=get_mem_map(ip->proc_nr, rmp->mp_seg)) != OK)
panic(__FILE__,"couldn't get process 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;
patch_mem_chunks(mem_chunks, rmp->mp_seg);
/* Tell FS about this system process. */
mess.PR_SLOT = ip->proc_nr;
mess.PR_PID = rmp->mp_pid;
mess.PR_ENDPT = rmp->mp_endpoint;
if (OK != (s=send(FS_PROC_NR, &mess)))
panic(__FILE__,"can't sync up with FS", s);
printf(" %s", ip->proc_name); /* display process name */
}
}
printf(".\n"); /* last process done */
/* Override some details. INIT, PM, FS and RS are somewhat special. */
mproc[PM_PROC_NR].mp_pid = PM_PID; /* PM has magic pid */
mproc[RS_PROC_NR].mp_parent = INIT_PROC_NR; /* INIT is root */
sigfillset(&mproc[PM_PROC_NR].mp_ignore); /* guard against signals */
/* Tell FS that no more system processes follow and synchronize. */
mess.PR_ENDPT = NONE;
if (sendrec(FS_PROC_NR, &mess) != OK || mess.m_type != OK)
panic(__FILE__,"can't sync up with FS", NO_NUM);
#if ENABLE_BOOTDEV
/* Possibly we must correct the memory chunks for the boot device. */
if (kinfo.bootdev_size > 0) {
mem_map[T].mem_phys = kinfo.bootdev_base >> CLICK_SHIFT;
mem_map[T].mem_len = 0;
mem_map[D].mem_len = (kinfo.bootdev_size+CLICK_SIZE-1) >> CLICK_SHIFT;
patch_mem_chunks(mem_chunks, mem_map);
}
#endif /* ENABLE_BOOTDEV */
/* Withhold some memory from x86 VM */
do_x86_vm(mem_chunks);
/* Initialize tables to all physical memory and print memory information. */
printf("Physical memory:");
mem_init(mem_chunks, &free_clicks);
total_clicks = minix_clicks + free_clicks;
printf(" total %u KB,", click_to_round_k(total_clicks));
printf(" system %u KB,", click_to_round_k(minix_clicks));
printf(" free %u KB.\n", click_to_round_k(free_clicks));
}
/*===========================================================================*
* get_nice_value *
*===========================================================================*/
PRIVATE int get_nice_value(queue)
int queue; /* store mem chunks here */
{
/* Processes in the boot image have a priority assigned. The PM doesn't know
* about priorities, but uses 'nice' values instead. The priority is between
* MIN_USER_Q and MAX_USER_Q. We have to scale between PRIO_MIN and PRIO_MAX.
*/
int nice_val = (queue - USER_Q) * (PRIO_MAX-PRIO_MIN+1) /
(MIN_USER_Q-MAX_USER_Q+1);
if (nice_val > PRIO_MAX) nice_val = PRIO_MAX; /* shouldn't happen */
if (nice_val < PRIO_MIN) nice_val = PRIO_MIN; /* shouldn't happen */
return nice_val;
}
#if _WORD_SIZE == 2
/* In real mode only 1M can be addressed, and in 16-bit protected we can go
* no further than we can count in clicks. (The 286 is further limited by
* its 24 bit address bus, but we can assume in that case that no more than
* 16M memory is reported by the BIOS.)
*/
#define MAX_REAL 0x00100000L
#define MAX_16BIT (0xFFF0L << CLICK_SHIFT)
#endif
/*===========================================================================*
* get_mem_chunks *
*===========================================================================*/
PRIVATE void get_mem_chunks(mem_chunks)
struct memory *mem_chunks; /* store mem chunks here */
{
/* Initialize the free memory list from the 'memory' boot variable. Translate
* the byte offsets and sizes in this list to clicks, properly truncated. Also
* make sure that we don't exceed the maximum address space of the 286 or the
* 8086, i.e. when running in 16-bit protected mode or real mode.
*/
long base, size, limit;
char *s, *end; /* use to parse boot variable */
int i, done = 0;
struct memory *memp;
#if _WORD_SIZE == 2
unsigned long max_address;
struct machine machine;
if (OK != (i=sys_getmachine(&machine)))
panic(__FILE__, "sys_getmachine failed", i);
#endif
/* Initialize everything to zero. */
for (i = 0; i < NR_MEMS; i++) {
memp = &mem_chunks[i]; /* next mem chunk is stored here */
memp->base = memp->size = 0;
}
/* The available memory is determined by MINIX' boot loader as a list of
* (base:size)-pairs in boothead.s. The 'memory' boot variable is set in
* in boot.s. The format is "b0:s0,b1:s1,b2:s2", where b0:s0 is low mem,
* b1:s1 is mem between 1M and 16M, b2:s2 is mem above 16M. Pairs b1:s1
* and b2:s2 are combined if the memory is adjacent.
*/
s = find_param("memory"); /* get memory boot variable */
for (i = 0; i < NR_MEMS && !done; i++) {
memp = &mem_chunks[i]; /* next mem chunk is stored here */
base = size = 0; /* initialize next base:size pair */
if (*s != 0) { /* get fresh data, unless at end */
/* Read fresh base and expect colon as next char. */
base = strtoul(s, &end, 0x10); /* get number */
if (end != s && *end == ':') s = ++end; /* skip ':' */
else *s=0; /* terminate, should not happen */
/* Read fresh size and expect comma or assume end. */
size = strtoul(s, &end, 0x10); /* get number */
if (end != s && *end == ',') s = ++end; /* skip ',' */
else done = 1;
}
limit = base + size;
#if _WORD_SIZE == 2
max_address = machine.protected ? MAX_16BIT : MAX_REAL;
if (limit > max_address) limit = max_address;
#endif
base = (base + CLICK_SIZE-1) & ~(long)(CLICK_SIZE-1);
limit &= ~(long)(CLICK_SIZE-1);
if (limit <= base) continue;
memp->base = base >> CLICK_SHIFT;
memp->size = (limit - base) >> CLICK_SHIFT;
}
}
/*===========================================================================*
* patch_mem_chunks *
*===========================================================================*/
PRIVATE void patch_mem_chunks(mem_chunks, map_ptr)
struct memory *mem_chunks; /* store mem chunks here */
struct mem_map *map_ptr; /* memory to remove */
{
/* Remove server memory from the free memory list. The boot monitor
* promises to put processes at the start of memory chunks. The
* tasks all use same base address, so only the first task changes
* the memory lists. The servers and init have their own memory
* spaces and their memory will be removed from the list.
*/
struct memory *memp;
for (memp = mem_chunks; memp < &mem_chunks[NR_MEMS]; memp++) {
if (memp->base == map_ptr[T].mem_phys) {
memp->base += map_ptr[T].mem_len + map_ptr[D].mem_len;
memp->size -= map_ptr[T].mem_len + map_ptr[D].mem_len;
}
}
}
#define PAGE_SIZE 4096
#define PAGE_TABLE_COVER (1024*PAGE_SIZE)
/*=========================================================================*
* do_x86_vm *
*=========================================================================*/
PRIVATE void do_x86_vm(mem_chunks)
struct memory mem_chunks[NR_MEMS];
{
phys_bytes high, bytes;
phys_clicks clicks, base_click;
unsigned pages;
int i, r;
/* Compute the highest memory location */
high= 0;
for (i= 0; i<NR_MEMS; i++)
{
if (mem_chunks[i].size == 0)
continue;
if (mem_chunks[i].base + mem_chunks[i].size > high)
high= mem_chunks[i].base + mem_chunks[i].size;
}
high <<= CLICK_SHIFT;
#if VERBOSE_VM
printf("do_x86_vm: found high 0x%x\n", high);
#endif
/* The number of pages we need is one for the page directory, enough
* page tables to cover the memory, and one page for alignement.
*/
pages= 1 + (high + PAGE_TABLE_COVER-1)/PAGE_TABLE_COVER + 1;
bytes= pages*PAGE_SIZE;
clicks= (bytes + CLICK_SIZE-1) >> CLICK_SHIFT;
#if VERBOSE_VM
printf("do_x86_vm: need %d pages\n", pages);
printf("do_x86_vm: need %d bytes\n", bytes);
printf("do_x86_vm: need %d clicks\n", clicks);
#endif
for (i= 0; i<NR_MEMS; i++)
{
if (mem_chunks[i].size <= clicks)
continue;
break;
}
if (i >= NR_MEMS)
panic("PM", "not enough memory for VM page tables?", NO_NUM);
base_click= mem_chunks[i].base;
mem_chunks[i].base += clicks;
mem_chunks[i].size -= clicks;
#if VERBOSE_VM
printf("do_x86_vm: using 0x%x clicks @ 0x%x\n", clicks, base_click);
#endif
r= sys_vm_setbuf(base_click << CLICK_SHIFT, clicks << CLICK_SHIFT,
high);
if (r != 0)
printf("do_x86_vm: sys_vm_setbuf failed: %d\n", r);
}
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