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/*
* Copyright (c) 1996, 1998, 1999 University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
/*
* Notes:
*
* What about locking and other issues of execution environments.
*
* I'm not using superpages at all. That complicates things 'cause anytime
* an application wants to modify a page in a superpage, the entire superpage
* has to be broken up into invidual pages. Too nasty for a first draft.
*
* Unused memory cannot be protected since the lmm requires write
* access to the pages to maintain the free lists. Besides, there is
* no telling what memory the kernel will access. This means the applicaton
* can write anything it wants to, except non-existent memory.
*
* I am allowing just READ and READ/WRITE prots. PROT_NONE is not
* allowed.
*
* Should morecore be redefined so that memory shortages in the malloc pool
* are handled properly?
*
* Pages are read and written to/from the swap area through the virtual
* address.
*/
/*
* Things to possibly do:
*
* 1) External pager interface. Add export of policy for selecting pages
* to aid in discardable page.
*
* 2) Provide support for specifying discardable pages (SML paper) and
* a way to flush disardable pages from the system.
*
* 3) In the threads world, use a thread for a simple pageout daemon.
*/
#include "svm_internal.h"
/*
* Use the AMM to track virtual mappings.
*/
amm_t svm_amm;
/*
* Application level SEGV handler for page faults.
*/
int (*svm_segv_handler)(oskit_addr_t la, int rw);
/*
* Enabled?
*/
int svm_enabled = 0;
/*
* Thread safe locking.
*/
oskit_lock_t *svm_lock = 0;
/*
* The VM region starts after the end of physical memory, and extends
* as far as possible.
*/
void
svm_init(oskit_absio_t *pager_absio)
{
oskit_lock_mgr_t *lock_mgr;
if (svm_enabled)
return;
/*
* Machine dependent initialization.
*/
svm_machdep_init();
/*
* This turns on paging!
*/
base_paging_load();
/*
* Initialize the stuff for catching stack overflow.
*/
svm_redzone_init();
/*
* See if thread-safe locks are required.
*/
if (oskit_lookup_first(&oskit_lock_mgr_iid, (void *) &lock_mgr))
panic("svm_init: oskit_lookup_first");
if (lock_mgr) {
if (oskit_lock_mgr_allocate_lock(lock_mgr, &svm_lock))
panic("svm_init: oskit_lock_mgr_allocate_lock");
}
/*
* XXX: Must turn this on before starting the pager. See mem.c
*/
svm_enabled = 1;
/*
* Initialize the pager if requested.
*/
if (pager_absio) {
if (svm_pager_init(pager_absio))
panic("svm_init: Could init the pager!\n");
}
/*
* Hook in a new page fault handler.
*/
base_trap_handlers[T_PAGE_FAULT] = svm_page_fault_handler;
/*
* and initialize the application level handler to null so
* that the default is to send a SIGSEGV to the application.
*/
svm_segv_handler = 0;
}
void
svm_shutdown()
{
extern int svm_pagein_count, svm_pageout_count;
extern int svm_pagein_time, svm_pageout_time;
extern int svm_swapread_time, svm_swapwrite_time;
extern int svm_swapwrite_count, svm_swapread_count;
printf("svm_shutdown: swapread count: %d pages. time %d\n"
" swapwrite count: %d pages. time %d\n",
svm_swapread_count, svm_swapread_time,
svm_swapwrite_count, svm_swapwrite_time);
printf("svm_shutdown: pagein count: %d pages. time %d\n"
" pageout count: %d pages. time %d\n",
svm_pagein_count, svm_pagein_time,
svm_pageout_count, svm_pageout_time);
}
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