Changeset 635 for trunk/kernel/libk/remote_sem.c

Timestamp:

Jun 26, 2019, 11:42:37 AM (5 years ago)

Author:

alain

Message:

This version is a major evolution: The physical memory allocators,
defined in the kmem.c, ppm.c, and kcm.c files have been modified
to support remote accesses. The RPCs that were previously user
to allocate physical memory in a remote cluster have been removed.
This has been done to cure a dead-lock in case of concurrent page-faults.

This version 2.2 has been tested on a (4 clusters / 2 cores per cluster)
TSAR architecture, for both the "sort" and the "fft" applications.

File:

• trunk/kernel/libk/remote_sem.c (modified) (5 diffs)

trunk/kernel/libk/remote_sem.c

@@ -2 +2 @@
  * remote_sem.c - POSIX unnamed semaphore implementation.
  * 
- * Author   Alain Greiner  (2016,2017,2018)
+ * Author   Alain Greiner  (2016,2017,2018,2019)
  *
  * Copyright (c) UPMC Sorbonne Universites
@@ -86 +86 @@
                            uint32_t   value )
 {
+    kmem_req_t     req;   
     remote_sem_t * sem_ptr;
-    xptr_t         sem_xp;
 
     // get pointer on local process descriptor
@@ -100 +100 @@
 
     // allocate memory for new semaphore in reference cluster
-    if( ref_cxy == local_cxy )  // local cluster is the reference 
-    {
-        kmem_req_t req;   
-        req.type  = KMEM_SEM;
-        req.flags = AF_ZERO;
-        sem_ptr   = kmem_alloc( &req );
-        sem_xp    = XPTR( local_cxy , sem_ptr );
+    req.type  = KMEM_KCM;
+    req.order = bits_log2( sizeof(remote_sem_t) );
+    req.flags = AF_ZERO | AF_KERNEL;
+    sem_ptr   = kmem_remote_alloc( ref_cxy, &req );
+
+    if( sem_ptr == NULL )
+    {
+        printk("\n[ERROR] in %s : cannot create semaphore\n", __FUNCTION__ );
+        return -1;
     }
-    else                         // reference is remote
-    {
-        rpc_kcm_alloc_client( ref_cxy , KMEM_SEM , &sem_xp );
-        sem_ptr = GET_PTR( sem_xp );
-    }
-
-    if( sem_xp == XPTR_NULL ) return 0xFFFFFFFF;
 
     // initialise semaphore 
@@ -149 +144 @@
 void remote_sem_destroy( xptr_t sem_xp )
 {
+    kmem_req_t  req;
+
     // get pointer on local process descriptor
     process_t * process = CURRENT_THREAD->process;
@@ -179 +176 @@
 
     // release memory allocated for semaphore descriptor
-    if( sem_cxy == local_cxy )                            // reference is local
-    {
-        kmem_req_t  req;
-        req.type = KMEM_SEM;
-        req.ptr  = sem_ptr;
-        kmem_free( &req );
-    }
-    else                                                  // reference is remote
-    {
-        rpc_kcm_free_client( sem_cxy , sem_ptr , KMEM_SEM );
-    }
+    req.type = KMEM_KCM;
+    req.ptr  = sem_ptr;
+    kmem_remote_free( sem_cxy , &req );
 
 }  // end remote_sem_destroy()