Changeset 619 for trunk/kernel/mm/vmm.c

Timestamp:

Feb 12, 2019, 1:15:47 PM (6 years ago)

Author:

alain

Message:

1) Fix a bug in KSH : after the "load" command,

the [ksh] prompt is now printed after completion
of the loaded application.

2) Fix a bug in vmm_handle_cow() : the copy-on-write

use now a hal_remote_memcpy() to replicate the page content.

File:

• trunk/kernel/mm/vmm.c (modified) (12 diffs)

trunk/kernel/mm/vmm.c

@@ -800 +800 @@
     // scan the VSL to delete all registered vsegs
     // (don't use a FOREACH for item deletion in xlist)
-        while( !xlist_is_empty( root_xp ) )
+
+uint32_t count = 0;
+
+        while( !xlist_is_empty( root_xp ) && (count < 10 ) )
         {
         // get pointer on first vseg in VSL
@@ -814 +817 @@
 __FUNCTION__ , vseg_type_str( vseg->type ), vseg->vpn_base, vseg->vpn_size );
 #endif
+
+count++;
 
         }
@@ -1463 +1468 @@
 
 #if DEBUG_VMM_ALLOCATE_PAGE
-uint32_t   cycle = (uint32_t)hal_get_cycles();
-thread_t * this  = CURRENT_THREAD;
+uint32_t   cycle   = (uint32_t)hal_get_cycles();
+thread_t * this    = CURRENT_THREAD;
+xptr_t     this_xp = XPTR( local_cxy , this );
 if( DEBUG_VMM_ALLOCATE_PAGE < (uint32_t)hal_get_cycles() )
 printk("\n[%s] thread[%x,%x] enter for vpn %x / cycle %d\n",
@@ -1950 +1956 @@
 
 #if DEBUG_VMM_HANDLE_COW
-uint32_t   cycle = (uint32_t)hal_get_cycles();
-thread_t * this  = CURRENT_THREAD;
+uint32_t   cycle   = (uint32_t)hal_get_cycles();
+thread_t * this    = CURRENT_THREAD;
+xptr_t     this_xp = XPTR( local_cxy , this );
 if( DEBUG_VMM_HANDLE_COW < cycle )
 printk("\n[%s] thread[%x,%x] enter for vpn %x / core[%x,%d] / cycle %d\n",
-__FUNCTION__, process->pid, this->trdid, vpn, local_cxy, this->core->lid, cycle );
+__FUNCTION__, this->process->pid, this->trdid, vpn, local_cxy, this->core->lid, cycle );
 #endif
 
@@ -1974 +1981 @@
     }
 
+#if( DEBUG_VMM_HANDLE_COW & 1)
+if( DEBUG_VMM_HANDLE_COW < cycle )
+printk("\n[%s] thread[%x,%x] get vseg for vpn %x\n",
+__FUNCTION__, this->process->pid, this->trdid, vpn );
+#endif
+
     // get reference GPT cluster and local pointer
     ref_cxy = GET_CXY( process->ref_xp );
@@ -2001 +2014 @@
                      &old_ppn );
 
+#if( DEBUG_VMM_HANDLE_COW & 1)
+if( DEBUG_VMM_HANDLE_COW < cycle )
+printk("\n[%s] thread[%x,%x] get pte for vpn %x : ppn %x / attr %x\n",
+__FUNCTION__, this->process->pid, this->trdid, vpn, old_ppn, old_attr );
+#endif
+
     // the PTE must be mapped for a COW
     if( (old_attr & GPT_MAPPED) == 0 )
@@ -2008 +2027 @@
 
         // release GPT lock in write mode
-        remote_rwlock_wr_acquire( gpt_lock_xp );
+        remote_rwlock_wr_release( gpt_lock_xp );
 
         return EXCP_KERNEL_PANIC;
     }
 
-    // get extended pointer, cluster and local pointer on physical page descriptor
+    // get pointers on physical page descriptor
     xptr_t   page_xp  = ppm_ppn2page( old_ppn );
     cxy_t    page_cxy = GET_CXY( page_xp );
@@ -2028 +2047 @@
     uint32_t forks = hal_remote_l32( forks_xp );
 
+#if( DEBUG_VMM_HANDLE_COW & 1)
+if( DEBUG_VMM_HANDLE_COW < cycle )
+printk("\n[%s] thread[%x,%x] get forks = %d for vpn %x\n",
+__FUNCTION__, this->process->pid, this->trdid, forks, vpn );
+#endif
+
     if( forks )        // pending fork => allocate a new page, and copy old to new
     {
-        // allocate a new physical page
+        // decrement pending forks counter in page descriptor
+        hal_remote_atomic_add( forks_xp , -1 );
+
+        // release lock protecting "forks" counter
+        remote_busylock_release( forks_lock_xp );
+
+        // allocate a new page
         page_xp = vmm_page_allocate( vseg , vpn );
+
         if( page_xp == XPTR_NULL ) 
         {
@@ -2040 +2072 @@
             remote_rwlock_wr_acquire( gpt_lock_xp );
 
-            // release lock protecting "forks" counter
-            remote_busylock_release( forks_lock_xp );
-
             return EXCP_KERNEL_PANIC;
         }
@@ -2049 +2078 @@
         new_ppn = ppm_page2ppn( page_xp );
 
+#if( DEBUG_VMM_HANDLE_COW & 1)
+if( DEBUG_VMM_HANDLE_COW < cycle )
+printk("\n[%s] thread[%x,%x] get new ppn %x for vpn %x\n",
+__FUNCTION__, this->process->pid, this->trdid, new_ppn, vpn );
+#endif
+
         // copy old page content to new page
-        xptr_t  old_base_xp = ppm_ppn2base( old_ppn );
-        xptr_t  new_base_xp = ppm_ppn2base( new_ppn );
-        memcpy( GET_PTR( new_base_xp ),
-                GET_PTR( old_base_xp ),
-                CONFIG_PPM_PAGE_SIZE );
-
-        // decrement pending forks counter in page descriptor
-        hal_remote_atomic_add( forks_xp , -1 );
+        hal_remote_memcpy( ppm_ppn2base( new_ppn ),
+                           ppm_ppn2base( old_ppn ),
+                           CONFIG_PPM_PAGE_SIZE );
 
 #if(DEBUG_VMM_HANDLE_COW & 1)
 if( DEBUG_VMM_HANDLE_COW < cycle )
-printk("\n[%s] thread[%x,%x] : pending forks => allocate a new PPN %x\n",
-__FUNCTION__, process->pid, this->trdid, new_ppn );
+printk("\n[%s] thread[%x,%x] copied old page to new page\n",
+__FUNCTION__, this->process->pid, this->trdid );
 #endif
 
@@ -2068 +2098 @@
     else               // no pending fork => keep the existing page
     {
+        // release lock protecting "forks" counter
+        remote_busylock_release( forks_lock_xp );
 
 #if(DEBUG_VMM_HANDLE_COW & 1)
 if( DEBUG_VMM_HANDLE_COW < cycle )
-printk("\n[%s] thread[%x,%x]  no pending forks => keep existing PPN %x\n",
-__FUNCTION__, process->pid, this->trdid, new_ppn );
+printk("\n[%s] thread[%x,%x]  no pending forks / keep existing PPN %x\n",
+__FUNCTION__, this->process->pid, this->trdid, old_ppn );
 #endif
         new_ppn = old_ppn;
     }
-
-    // release lock protecting "forks" counter
-    remote_busylock_release( forks_lock_xp );
 
     // build new_attr : reset COW and set WRITABLE,
     new_attr = (old_attr | GPT_WRITABLE) & (~GPT_COW);
 
-    // update the relevan GPT
+    // update the relevant GPT
     // - private vseg => update local GPT 
     // - public vseg => update all GPT copies
@@ -2119 +2148 @@
 if( DEBUG_VMM_HANDLE_COW < cycle )
 printk("\n[%s] thread[%x,%x] exit for vpn %x / core[%x,%d] / cycle %d\n",
-__FUNCTION__, process->pid, this->trdid, vpn, local_cxy, this->core->lid, cycle );
+__FUNCTION__, this->process->pid, this->trdid, vpn, local_cxy, this->core->lid, cycle );
 #endif