From: Arun Thomas <arun@minix3.org>
Date: Sat, 5 Jun 2010 14:39:40 +0000 (+0000)
Subject: VM: Remove legacy non-paging code paths
X-Git-Tag: v3.1.8~499
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/jquery.js?a=commitdiff_plain;h=b641afc78a9c1b02b88a3fd14f653f853ad8cd4e;p=minix.git

VM: Remove legacy non-paging code paths
---

diff --git a/servers/pm/exec.c b/servers/pm/exec.c
index 350d0e6f7..3f74e7921 100644
--- a/servers/pm/exec.c
+++ b/servers/pm/exec.c
@@ -15,7 +15,6 @@
  *   do_exec_newmem: allocate new memory map for a process that tries to exec
  *   do_execrestart: finish the special exec call for RS
  *   exec_restart: finish a regular exec call
- *   find_share: find a process whose text segment can be shared
  */
 
 #include "pm.h"
diff --git a/servers/vm/alloc.c b/servers/vm/alloc.c
index f846b7467..9782d9ec6 100644
--- a/servers/vm/alloc.c
+++ b/servers/vm/alloc.c
@@ -181,43 +181,10 @@ PUBLIC phys_clicks alloc_mem(phys_clicks clicks, u32_t memflags)
 	clicks += align_clicks;
   }
 
-  if(vm_paged) {
-	mem = alloc_pages(clicks, memflags, NULL);
-	if(mem == NO_MEM) {
-		free_yielded(clicks * CLICK_SIZE);
-		mem = alloc_pages(clicks, memflags, NULL);
-	}
-  } else {
-CHECKHOLES;
-        prev_ptr = NULL;
-	hp = hole_head;
-	while (hp != NULL) {
-		if (hp->h_len >= clicks) {
-			/* We found a hole that is big enough.  Use it. */
-			old_base = hp->h_base;	/* remember where it started */
-			hp->h_base += clicks;	/* bite a piece off */
-			hp->h_len -= clicks;	/* ditto */
-
-			/* Delete the hole if used up completely. */
-			if (hp->h_len == 0) del_slot(prev_ptr, hp);
-
-			/* Anything special needs to happen? */
-			if(memflags & PAF_CLEAR) {
-			  if ((s= sys_memset(0, CLICK_SIZE*old_base,
-				CLICK_SIZE*clicks)) != OK)   {
-				panic("alloc_mem: sys_memset failed: %d", s);
-			  }
-			}
-
-			/* Return the start address of the acquired block. */
-CHECKHOLES;
-			mem = old_base;
-			break;
-		}
-
-		prev_ptr = hp;
-		hp = hp->h_next;
-	}
+  mem = alloc_pages(clicks, memflags, NULL);
+  if(mem == NO_MEM) {
+    free_yielded(clicks * CLICK_SIZE);
+    mem = alloc_pages(clicks, memflags, NULL);
   }
 
   if(mem == NO_MEM)
@@ -255,11 +222,9 @@ CHECKHOLES;
 
   if (clicks == 0) return;
 
-  if(vm_paged) {
-	assert(CLICK_SIZE == VM_PAGE_SIZE);
-	free_pages(base, clicks);
-	return;
-  }
+  assert(CLICK_SIZE == VM_PAGE_SIZE);
+  free_pages(base, clicks);
+  return;
 
   if ( (new_ptr = free_slots) == NULL) 
   	panic("hole table full");
diff --git a/servers/vm/exec.c b/servers/vm/exec.c
index f91a5f9e2..27045d54f 100644
--- a/servers/vm/exec.c
+++ b/servers/vm/exec.c
@@ -30,41 +30,12 @@
 
 #include "memory.h"
 
-FORWARD _PROTOTYPE( int new_mem, (struct vmproc *vmp, struct vmproc *sh_vmp,
+FORWARD _PROTOTYPE( int new_mem, (struct vmproc *vmp,
 	vir_bytes text_bytes, vir_bytes data_bytes, vir_bytes bss_bytes,
 	vir_bytes stk_bytes, phys_bytes tot_bytes, vir_bytes *stack_top));
 
 static int failcount;
 
-/*===========================================================================*
- *                              find_share                                   *
- *===========================================================================*/
-PUBLIC struct vmproc *find_share( 
-  struct vmproc *vmp_ign,       /* process that should not be looked at */
-  ino_t ino,                    /* parameters that uniquely identify a file */
-  dev_t dev,
-  time_t ctime
-)
-{
-/* Look for a process that is the file <ino, dev, ctime> in execution.  Don't
- * accidentally "find" vmp_ign, because it is the process on whose behalf this
- * call is made.
- */
-  struct vmproc *vmp;
-  for (vmp = &vmproc[0]; vmp < &vmproc[NR_PROCS]; vmp++) {
-        if (!(vmp->vm_flags & VMF_INUSE)) continue;
-        if (!(vmp->vm_flags & VMF_SEPARATE)) continue;
-        if (vmp->vm_flags & VMF_HASPT) continue;
-        if (vmp == vmp_ign) continue;
-        if (vmp->vm_ino != ino) continue;
-        if (vmp->vm_dev != dev) continue;
-        if (vmp->vm_ctime != ctime) continue;
-        return vmp;
-  }
-  return(NULL);
-}
-
-
 /*===========================================================================*
  *				exec_newmem				     *
  *===========================================================================*/
@@ -73,7 +44,7 @@ PUBLIC int do_exec_newmem(message *msg)
 	int r, proc_e, proc_n;
 	vir_bytes stack_top;
 	vir_clicks tc, dc, sc, totc, dvir, s_vir;
-	struct vmproc *vmp, *sh_mp;
+	struct vmproc *vmp;
 	char *ptr;
 	struct exec_newmem args;
 
@@ -126,17 +97,10 @@ SANITYCHECK(SCL_DETAIL);
 		return r;
 	}
 
-	/* Can the process' text be shared with that of one already running? */
-	if(!vm_paged) {
-		sh_mp = find_share(vmp, args.st_ino, args.st_dev, args.st_ctime);
-	} else {
-		sh_mp = NULL;
-	}
-
 	/* Allocate new memory and release old memory.  Fix map and tell
 	 * kernel.
 	 */
-	r = new_mem(vmp, sh_mp, args.text_bytes, args.data_bytes,
+	r = new_mem(vmp, args.text_bytes, args.data_bytes,
 		args.bss_bytes, args.args_bytes, args.tot_bytes, &stack_top);
 	if (r != OK) {
 		printf("VM: newmem: new_mem failed\n");
@@ -156,8 +120,7 @@ SANITYCHECK(SCL_DETAIL);
 
 	msg->VMEN_STACK_TOP = (void *) stack_top;
 	msg->VMEN_FLAGS = 0;
-	if (!sh_mp)			 /* Load text if sh_mp = NULL */
-		msg->VMEN_FLAGS |= EXC_NM_RF_LOAD_TEXT;
+	msg->VMEN_FLAGS |= EXC_NM_RF_LOAD_TEXT;
 
 	return OK;
 }
@@ -165,10 +128,9 @@ SANITYCHECK(SCL_DETAIL);
 /*===========================================================================*
  *				new_mem					     *
  *===========================================================================*/
-PRIVATE int new_mem(rmp, sh_mp, text_bytes, data_bytes,
+PRIVATE int new_mem(rmp, text_bytes, data_bytes,
 	bss_bytes,stk_bytes,tot_bytes,stack_top)
 struct vmproc *rmp;		/* process to get a new memory map */
-struct vmproc *sh_mp;		/* text can be shared with this process */
 vir_bytes text_bytes;		/* text segment size in bytes */
 vir_bytes data_bytes;		/* size of initialized data in bytes */
 vir_bytes bss_bytes;		/* size of bss in bytes */
@@ -184,18 +146,11 @@ vir_bytes *stack_top;		/* top of process stack */
   phys_bytes bytes, base, bss_offset;
   int s, r2, r, hadpt = 0;
   struct vmproc *vmpold = &vmproc[VMP_EXECTMP];
+  int ptok = 1;
 
   SANITYCHECK(SCL_FUNCTIONS);
 
-  if(rmp->vm_flags & VMF_HASPT) {
-	hadpt = 1;
-  }
-
-  /* No need to allocate text if it can be shared. */
-  if (sh_mp != NULL) {
-	text_bytes = 0;
-	assert(!vm_paged);
-  }
+  assert(rmp->vm_flags & VMF_HASPT);
 
   /* Acquire the new memory.  Each of the 4 parts: text, (data+bss), gap,
    * and stack occupies an integral number of clicks, starting at click
@@ -221,42 +176,26 @@ vir_bytes *stack_top;		/* top of process stack */
    * Just recreate it in the case that we have to revert.
    */
 SANITYCHECK(SCL_DETAIL);
-  if(hadpt) {
-	  rmp->vm_flags &= ~VMF_HASPT;
-	  pt_free(&rmp->vm_pt);
-  }
+  rmp->vm_flags &= ~VMF_HASPT;
+  pt_free(&rmp->vm_pt);
+
   assert(!(vmpold->vm_flags & VMF_INUSE));
   *vmpold = *rmp;	/* copy current state. */
   rmp->vm_regions = NULL; /* exec()ing process regions thrown out. */
 SANITYCHECK(SCL_DETAIL);
 
-  if(!hadpt) {
-  	if (find_share(rmp, rmp->vm_ino, rmp->vm_dev, rmp->vm_ctime) == NULL) {
-		/* No other process shares the text segment, so free it. */
-		free_mem(rmp->vm_arch.vm_seg[T].mem_phys, rmp->vm_arch.vm_seg[T].mem_len);
-  	}
-
-  	/* Free the data and stack segments. */
-  	free_mem(rmp->vm_arch.vm_seg[D].mem_phys,
-		rmp->vm_arch.vm_seg[S].mem_vir
-		+ rmp->vm_arch.vm_seg[S].mem_len
-		- rmp->vm_arch.vm_seg[D].mem_vir);
-  }
 
   /* Build new process in current slot, without freeing old
    * one. If it fails, revert.
    */
+  SANITYCHECK(SCL_DETAIL);
+  if((r=pt_new(&rmp->vm_pt)) != OK) {
+    ptok = 0;
+    printf("exec_newmem: no new pagetable\n");
+  }
 
-  if(vm_paged) {
-	int ptok = 1;
-	SANITYCHECK(SCL_DETAIL);
-	if((r=pt_new(&rmp->vm_pt)) != OK) {
-		ptok = 0;
-		printf("exec_newmem: no new pagetable\n");
-	}
-
-	SANITYCHECK(SCL_DETAIL);
-	if(r != OK || (r=proc_new(rmp,
+  SANITYCHECK(SCL_DETAIL);
+  if(r != OK || (r=proc_new(rmp,
 	 VM_PROCSTART,	/* where to start the process in the page table */
 	 CLICK2ABS(text_clicks),/* how big is the text in bytes, page-aligned */
 	 CLICK2ABS(data_clicks),/* how big is data+bss, page-aligned */
@@ -265,112 +204,42 @@ SANITYCHECK(SCL_DETAIL);
 	 0,0,			/* not preallocated */
 	 VM_STACKTOP,		/* regular stack top */
 	 0)) != OK) {
-		SANITYCHECK(SCL_DETAIL);
-		printf("VM: new_mem: failed\n");
-		if(ptok) {
-	  		rmp->vm_flags &= ~VMF_HASPT;
-			pt_free(&rmp->vm_pt);
-		}
-		*rmp = *vmpold;	/* undo. */
-		clear_proc(vmpold);	/* disappear. */
-		SANITYCHECK(SCL_DETAIL);
-		if(hadpt) {
-			if(pt_new(&rmp->vm_pt) != OK) {
-			/* We secretly know that making a new pagetable
-			 * in the same slot if one was there will never fail.
-			 */
-				panic("new_mem: pt_new failed: %d", ENOMEM);
-			}
-			rmp->vm_flags |= VMF_HASPT;
-			SANITYCHECK(SCL_DETAIL);
-			if(map_writept(rmp) != OK) {
-				printf("VM: warning: exec undo failed\n");
-			}
-			SANITYCHECK(SCL_DETAIL);
-		}
-		return r;
-	}
-	SANITYCHECK(SCL_DETAIL);
-	/* new process is made; free and unreference
-	 * page table and memory still held by exec()ing process.
+    SANITYCHECK(SCL_DETAIL);
+    printf("VM: new_mem: failed\n");
+    if(ptok) {
+      rmp->vm_flags &= ~VMF_HASPT;
+      pt_free(&rmp->vm_pt);
+    }
+    *rmp = *vmpold;	/* undo. */
+    clear_proc(vmpold);	/* disappear. */
+    SANITYCHECK(SCL_DETAIL);
+    if(hadpt) {
+      if(pt_new(&rmp->vm_pt) != OK) {
+	/* We secretly know that making a new pagetable
+	 * in the same slot if one was there will never fail.
 	 */
-	SANITYCHECK(SCL_DETAIL);
-	free_proc(vmpold);
-	clear_proc(vmpold);	/* disappear. */
-	SANITYCHECK(SCL_DETAIL);
-	*stack_top = VM_STACKTOP;
-  } else {
-  	phys_clicks new_base;
-
-	new_base = alloc_mem(text_clicks + tot_clicks, 0);
-	if (new_base == NO_MEM) {
-		printf("VM: new_mem: alloc_mem failed\n");
-		return(ENOMEM);
-	}
-
-	if (sh_mp != NULL) {
-		/* Share the text segment. */
-		rmp->vm_arch.vm_seg[T] = sh_mp->vm_arch.vm_seg[T];
-	} else {
-		rmp->vm_arch.vm_seg[T].mem_phys = new_base;
-		rmp->vm_arch.vm_seg[T].mem_vir = 0;
-		rmp->vm_arch.vm_seg[T].mem_len = text_clicks;
-	
-		if (text_clicks > 0)
-		{
-			/* Zero the last click of the text segment. Otherwise the
-			 * part of that click may remain unchanged.
-			 */
-			base = (phys_bytes)(new_base+text_clicks-1) << CLICK_SHIFT;
-			if ((s= sys_memset(0, base, CLICK_SIZE)) != OK)
-				panic("new_mem: sys_memset failed: %d", s);
-		}
-  	}
-
-	/* No paging stuff. */
-	rmp->vm_flags &= ~VMF_HASPT;
-	rmp->vm_regions = NULL;
-
-	  rmp->vm_arch.vm_seg[D].mem_phys = new_base + text_clicks;
-	  rmp->vm_arch.vm_seg[D].mem_vir = 0;
-	  rmp->vm_arch.vm_seg[D].mem_len = data_clicks;
-	  rmp->vm_arch.vm_seg[S].mem_phys = rmp->vm_arch.vm_seg[D].mem_phys +
-		data_clicks + gap_clicks;
-	  rmp->vm_arch.vm_seg[S].mem_vir = rmp->vm_arch.vm_seg[D].mem_vir +
-		data_clicks + gap_clicks;
-	  rmp->vm_arch.vm_seg[S].mem_len = stack_clicks;
-	rmp->vm_stacktop =
-		CLICK2ABS(rmp->vm_arch.vm_seg[S].mem_vir +
-			rmp->vm_arch.vm_seg[S].mem_len);
-
-	rmp->vm_arch.vm_data_top = 
-		(rmp->vm_arch.vm_seg[S].mem_vir + 
-		rmp->vm_arch.vm_seg[S].mem_len) << CLICK_SHIFT;
-
-	  if((r2=sys_newmap(rmp->vm_endpoint, rmp->vm_arch.vm_seg)) != OK) {
-		/* report new map to the kernel */
-		panic("sys_newmap failed: %d", r2);
-	  }
-
-	  /* Zero the bss, gap, and stack segment. */
-	  bytes = (phys_bytes)(data_clicks + gap_clicks + stack_clicks) << CLICK_SHIFT;
-	  base = (phys_bytes) rmp->vm_arch.vm_seg[D].mem_phys << CLICK_SHIFT;
-	  bss_offset = (data_bytes >> CLICK_SHIFT) << CLICK_SHIFT;
-	  base += bss_offset;
-	  bytes -= bss_offset;
-
-	  if ((s=sys_memset(0, base, bytes)) != OK) {
-		panic("new_mem can't zero: %d", s);
-	  }
-
-	  /* Tell kernel this thing has no page table. */
-	  if((s=pt_bind(NULL, rmp)) != OK)
-		panic("exec_newmem: pt_bind failed: %d", s);
-	*stack_top= ((vir_bytes)rmp->vm_arch.vm_seg[S].mem_vir << CLICK_SHIFT) +
-               ((vir_bytes)rmp->vm_arch.vm_seg[S].mem_len << CLICK_SHIFT);
+	panic("new_mem: pt_new failed: %d", ENOMEM);
+      }
+      rmp->vm_flags |= VMF_HASPT;
+      SANITYCHECK(SCL_DETAIL);
+      if(map_writept(rmp) != OK) {
+	printf("VM: warning: exec undo failed\n");
+      }
+      SANITYCHECK(SCL_DETAIL);
+    }
+    return r;
   }
+  SANITYCHECK(SCL_DETAIL);
+  /* new process is made; free and unreference
+   * page table and memory still held by exec()ing process.
+   */
+  SANITYCHECK(SCL_DETAIL);
+  free_proc(vmpold);
+  clear_proc(vmpold);	/* disappear. */
+  SANITYCHECK(SCL_DETAIL);
+  *stack_top = VM_STACKTOP;
 
-SANITYCHECK(SCL_FUNCTIONS);
+  SANITYCHECK(SCL_FUNCTIONS);
 
   return(OK);
 }
diff --git a/servers/vm/exit.c b/servers/vm/exit.c
index ef13615d4..9afee36e4 100644
--- a/servers/vm/exit.c
+++ b/servers/vm/exit.c
@@ -70,25 +70,12 @@ SANITYCHECK(SCL_FUNCTIONS);
 
 	if(vmp->vm_flags & VMF_HAS_DMA) {
 		release_dma(vmp);
-	} else if(vmp->vm_flags & VMF_HASPT) {
+	} else {
+		assert(vmp->vm_flags & VMF_HASPT);
 		/* Free pagetable and pages allocated by pt code. */
 SANITYCHECK(SCL_DETAIL);
 		free_proc(vmp);
 SANITYCHECK(SCL_DETAIL);
-	} else {
-		/* Free the data and stack segments. */
-		free_mem(vmp->vm_arch.vm_seg[D].mem_phys,
-			vmp->vm_arch.vm_seg[S].mem_vir +
-			vmp->vm_arch.vm_seg[S].mem_len -
-			vmp->vm_arch.vm_seg[D].mem_vir);
-
-		if (find_share(vmp, vmp->vm_ino, vmp->vm_dev, vmp->vm_ctime) == NULL) {
-			/* No other process shares the text segment,
-			 * so free it.
-			 */
-			free_mem(vmp->vm_arch.vm_seg[T].mem_phys,
-			vmp->vm_arch.vm_seg[T].mem_len);
-		}
 	}
 SANITYCHECK(SCL_DETAIL);
 
diff --git a/servers/vm/glo.h b/servers/vm/glo.h
index 49f82ec82..8616f79a6 100644
--- a/servers/vm/glo.h
+++ b/servers/vm/glo.h
@@ -27,7 +27,4 @@ EXTERN long vm_sanitychecklevel;
 /* total number of memory pages */
 EXTERN int total_pages;
 
-/* vm operation mode state and values */
-EXTERN long vm_paged;
-
 EXTERN int meminit_done;
diff --git a/servers/vm/main.c b/servers/vm/main.c
index 0d49a4958..fd9490a8d 100644
--- a/servers/vm/main.c
+++ b/servers/vm/main.c
@@ -183,8 +183,6 @@ PRIVATE int sef_cb_init_fresh(int type, sef_init_info_t *info)
 	incheck = nocheck = 0;
 #endif
 
-	vm_paged = 1;
-	env_parse("vm_paged", "d", 0, &vm_paged, 0, 1);
 #if SANITYCHECKS
 	env_parse("vm_sanitychecklevel", "d", 0, &vm_sanitychecklevel, 0, SCL_MAX);
 #endif
diff --git a/servers/vm/proto.h b/servers/vm/proto.h
index be635a069..fb20c424d 100644
--- a/servers/vm/proto.h
+++ b/servers/vm/proto.h
@@ -56,8 +56,6 @@ _PROTOTYPE( void free_proc, (struct vmproc *vmp)			);
 _PROTOTYPE( int do_fork, (message *msg)					);
 
 /* exec.c */
-_PROTOTYPE( struct vmproc *find_share, (struct vmproc *vmp_ign, Ino_t ino,
-                        dev_t dev, time_t ctime)                        );
 _PROTOTYPE( int do_exec_newmem, (message *msg)				);
 _PROTOTYPE( int proc_new, (struct vmproc *vmp, phys_bytes start,
 	phys_bytes text, phys_bytes data, phys_bytes stack, phys_bytes gap,
diff --git a/servers/vm/region.c b/servers/vm/region.c
index a4ac327ee..9a9f18c0f 100644
--- a/servers/vm/region.c
+++ b/servers/vm/region.c
@@ -348,9 +348,6 @@ PRIVATE vir_bytes region_find_slot(struct vmproc *vmp,
 
 	SANITYCHECK(SCL_FUNCTIONS);
 
-	/* We must be in paged mode to be able to do this. */
-	assert(vm_paged);
-
 	/* Length must be reasonable. */
 	assert(length > 0);