hurd-0.8.tar.gz

/* * Mach Operating System * Copyright (c) 1993-1989 Carnegie Mellon University * All Rights Reserved. * * Permission to use, copy, modify and distribute this software and its * documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie Mellon * the rights to redistribute these changes. */ /* * Default pager. Pages to paging partition. * * MUST BE ABLE TO ALLOCATE WIRED-DOWN MEMORY!!! */ #include <mach.h> #include <mach/message.h> #include <mach/notify.h> #include <mach/mig_errors.h> #include <mach/thread_switch.h> #include <mach/task_info.h> #include <mach/default_pager_types.h> #include <pthread.h> #include <stddef.h> #include <device/device_types.h> #include <device/device.h> #include <hurd/ihash.h> #include "queue.h" #include "wiring.h" #include "kalloc.h" #include "default_pager.h" #include <assert.h> #include <errno.h> #include <stdio.h> #include <string.h> #include <stdarg.h> #include <file_io.h> #include "memory_object_S.h" #include "memory_object_default_S.h" #include "default_pager_S.h" #include "exc_S.h" #include "priv.h" #define debug 0 static char my_name[] = "(default pager):"; static void __attribute__ ((format (printf, 1, 2), unused)) synchronized_printf (const char *fmt, ...) { static pthread_mutex_t printf_lock = PTHREAD_MUTEX_INITIALIZER; va_list ap; va_start (ap, fmt); pthread_mutex_lock (&printf_lock); vprintf (fmt, ap); fflush (stdout); pthread_mutex_unlock (&printf_lock); va_end (ap); } #if 0 #define dprintf(f, x...) synchronized_printf (f, ##x) #else #define dprintf(f, x...) (void) 0 #endif #if 0 #define ddprintf(f, x...) synchronized_printf (f, ##x) #else #define ddprintf(f, x...) (void) 0 #endif /* * parallel vs serial switch */ #define PARALLEL 1 #if 0 #define CHECKSUM 1 #endif #define USE_PRECIOUS 1 #define ptoa(p) ((p)*vm_page_size) #define atop(a) ((a)/vm_page_size)  partition_t partition_of(x) int x; { if (x >= all_partitions.n_partitions || x < 0) panic("partition_of x%x", x); return all_partitions.partition_list[x]; } void set_partition_of(x, p) int x; partition_t p; { if (x >= all_partitions.n_partitions || x < 0) panic("set_partition_of x%x", x); all_partitions.partition_list[x] = p; } /* * Simple mapping from (file)NAME to id * Saves space, filenames can be long. */ unsigned int part_id(const char *name) { unsigned int id, xorid; size_t len; len = strlen(name); id = xorid = 0; while (len--) { xorid ^= *name; id += *name++; } return (id << 8) | xorid; } void partition_init() { pthread_mutex_init(&all_partitions.lock, NULL); all_partitions.n_partitions = 0; } static partition_t new_partition (const char *name, struct file_direct *fdp, int check_linux_signature) { partition_t part; vm_size_t size, bmsize; vm_offset_t raddr; mach_msg_type_number_t rsize; int rc; unsigned int id = part_id(name); unsigned int n = strlen(name); pthread_mutex_lock(&all_partitions.lock); { unsigned int i; for (i = 0; i < all_partitions.n_partitions; i++) { part = partition_of(i); if (part && part->id == id) { pthread_mutex_unlock(&all_partitions.lock); return 0; } } } pthread_mutex_unlock(&all_partitions.lock); size = atop(fdp->fd_size * fdp->fd_bsize); bmsize = howmany(size, NB_BM) * sizeof(bm_entry_t); part = (partition_t) kalloc(sizeof(struct part)); pthread_mutex_init(&part->p_lock, NULL); part->name = (char*) kalloc(n + 1); strcpy(part->name, name); part->total_size = size; part->free = size; part->id = id; part->bitmap = (bm_entry_t *)kalloc(bmsize); part->going_away= FALSE; part->file = fdp; memset ((char *)part->bitmap, 0, bmsize); if (check_linux_signature < 0) { if (check_linux_signature != -3) printf("(default pager): " "Paging to raw partition %s (%uk paging space)\n", name, part->total_size * (vm_page_size / 1024)); return part; } #define LINUX_PAGE_SIZE 4096 /* size of pages in Linux swap partitions */ rc = page_read_file_direct(part->file, 0, LINUX_PAGE_SIZE, &raddr, &rsize); if (rc) panic("(default pager): cannot read first page of %s! rc=%#x\n", name, rc); while (rsize < LINUX_PAGE_SIZE) { /* Filesystem block size is smaller than page size, so we must do several reads to get the whole page. */ vm_address_t baddr; vm_size_t bsize; rc = page_read_file_direct(part->file, rsize, LINUX_PAGE_SIZE-rsize, &baddr, &bsize); if (rc) panic("(default pager): " "cannot read first page of %s! rc=%#x at %#x\n", name, rc, rsize); memcpy ((char *) raddr + rsize, (void *) baddr, bsize); rsize += bsize; vm_deallocate (mach_task_self (), baddr, bsize); } if (!memcmp("SWAP-SPACE", (char *) raddr + LINUX_PAGE_SIZE-10, 10)) { /* The partition's first page has a Linux swap signature. This means the beginning of the page contains a bitmap of good pages, and all others are bad. */ unsigned int i, j, bad, max; int waste; printf("(default pager): Found Linux 2.0 swap signature in %s\n", name); /* The first page, and the pages corresponding to the bits occupied by the signature in the final 10 bytes of the page, are always unavailable ("bad"). */ *(u_int32_t *)raddr &= ~(u_int32_t) 1; memset((char *) raddr + LINUX_PAGE_SIZE-10, 0, 10); max = LINUX_PAGE_SIZE / sizeof(u_int32_t); if (max > (part->total_size + 31) / 32) max = (part->total_size + 31) / 32; bad = 0; for (i = 0; i < max; ++i) { u_int32_t bm = ((u_int32_t *) raddr)[i]; if (bm == ~(u_int32_t) 0) continue; /* There are some zero bits in this word. */ for (j = 0; j < 32; ++j) if ((bm & (1 << j)) == 0) { unsigned int p = i*32 + j; if (p >= part->total_size) break; ++bad; part->bitmap[p / NB_BM] |= 1 << (p % NB_BM); } } part->free -= bad; --bad; /* Don't complain about first page. */ waste = part->total_size - (8 * (LINUX_PAGE_SIZE-10)); if (waste > 0) { /* The wasted pages were already marked "bad". */ bad -= waste; if (bad > 0) printf("\ (default pager): Paging to %s, %dk swap-space (%dk bad, %dk wasted at end)\n", name, part->free * (LINUX_PAGE_SIZE / 1024), bad * (LINUX_PAGE_SIZE / 1024), waste * (LINUX_PAGE_SIZE / 1024)); else printf("\ (default pager): Paging to %s, %dk swap-space (%dk wasted at end)\n", name, part->free * (LINUX_PAGE_SIZE / 1024), waste * (LINUX_PAGE_SIZE / 1024)); } else if (bad > 0) printf("\ (default pager): Paging to %s, %dk swap-space (excludes %dk marked bad)\n", name, part->free * (LINUX_PAGE_SIZE / 1024), bad * (LINUX_PAGE_SIZE / 1024)); else printf("\ (default pager): Paging to %s, %dk swap-space\n", name, part->free * (LINUX_PAGE_SIZE / 1024)); } else if (!memcmp("SWAPSPACE2", (char *) raddr + LINUX_PAGE_SIZE-10, 10)) { struct { u_int8_t bootbits[1024]; u_int32_t version; u_int32_t last_page; u_int32_t nr_badpages;