Changes between Version 17 and Version 18 of page_tables

Timestamp:

Dec 20, 2019, 5:21:53 PM (4 years ago)

Author:

alain

Comment:

--

page_tables

@@ -7 +7 @@
 A vseg descriptor contains the following fields :
 
- * TYPE : Defines the replication/distribution policy (CODE / STACK / DATA / HEAP / HEAPXY / FILE / ANON)
+ * TYPE : Defines the replication/distribution policy
  * FLAGS : Defines access rights
  * VBASE : Base virtual address
  * LENGTH : Segment length
  * BIN : Pathname to the .elf file (only for DATA and CODE types).
- * X,Y : Coordinates of the cluster where the vseg is mapped (only for a localized vseg).
+ * CXY : cluster where the vseg is mapped (only for a localized vseg).
  * MAPPER : radix-tree containing the physical pages allocated to this vseg (only for CODE, DATA and FILE types).
 
 == __2) Page tables and vseg lists__ ==
 
-The various information associated to a process P can be found in the process descriptor (process_t structure). This process descriptor and the structures within are - partly - replicated in all clusters containing at least one thread of process P, these clusters are called "active" clusters.
+The various information associated to a process P can be found in the process descriptor (process_t structure). This process descriptor  is - partly - replicated in all clusters containing at least one thread of process P, these clusters are called "active" clusters.
 
 The '''VSL(P,K) ''' (virtual Segment List of process P in cluster K)  is replicated in all active clusters. It is used by the kernel when a page fault occurs, it checks that the unmapped virtual address corresponds to a registered segment and determines the segment type. 
@@ -26 +26 @@
 
 For a P process, the contents of the different page tables GPT(P,K) can changes over time, and it evolves differently in active clusters :
-On the one hand, the P page tables content evolves dynamically in the clusters depending on the page faults triggered by the thread of P running in each cluster.
+On the one hand, the P page tables content evolves dynamically in the clusters depending on the page faults triggered by the threads of P running in each cluster.
 Moreover, the ''private'' segments mapping (CODE and STACK types) differs from one cluster to another, since a same virtual address corresponds to different addresses depending on the cluster.
 For ''public'' vsegs, only the reference cluster contains the complete mapping state.
@@ -134 +134 @@
 and initialized the physical page in M via a remote_memcpy(). Then it updates the PT(P,Z).
 
-=== 4.4) HEAP ===
+=== 4.4) ANON ===
 This vseg being ''distributed'', the physical pages are distributed among all the cluster depending on the VPN LSBs.
 If the K cluster, that detects the page fault, is different from the owner Z cluster, then the kernel instance of cluster K sends a PT_MISS_RPC
@@ -167 +167 @@
 When the kernel instance of cluster Z obtains the PPN, it updates the PT(P,Z).
 
-=== 4.7) ANON ===
-This vseg being distributed, the physical pages are distributed among all cluster depending the VPN LSBs.
-The handling of a page fault is the same as for a HEAP vseg.
 
 == __5) Invalidation of an entry in the page table__ ==