patch-2.1.53 linux/Documentation/powerpc/ppc_htab.txt
Next file: linux/Makefile
Previous file: linux/Documentation/powerpc/00-INDEX
Back to the patch index
Back to the overall index
- Lines: 51
- Date:
Thu Sep 4 12:54:48 1997
- Orig file:
v2.1.52/linux/Documentation/powerpc/ppc_htab.txt
- Orig date:
Wed Dec 31 16:00:00 1969
diff -u --recursive --new-file v2.1.52/linux/Documentation/powerpc/ppc_htab.txt linux/Documentation/powerpc/ppc_htab.txt
@@ -0,0 +1,50 @@
+ Information about /proc/ppc_htab
+=====================================================================
+
+This entry in the proc directory is readable by all users but only
+writable by root.
+
+
+1. Reading
+
+ Reading this file will give you information about the memory management
+ hash table that serves as an extended tlb for page translation on the
+ powerpc.
+
+ Explaination of the fields:
+
+ Size - hash table size in Kb.
+ Buckets - number of buckets in the table.
+ Addess - the virtual kernel address of the hash table base.
+ Entries - the number of ptes that can be stored in the hash table.
+ User/Kernel - how many pte's are in use by the kernel or user at that time.
+ Overflows - How many of the entries are in their secondary hash location.
+ Percent full - ratio of free pte entries to in use entries.
+
+ Note that calculation of the data displayed from /proc/ppc_htab takes
+ a long time and spends a great deal of time in the kernel. It would
+ be quite hard on performance to read this file constantly. In time
+ there may be a counter in the kernel that allows successive reads from
+ this file only after a given amount of time has passed to reduce the
+ possibility of a user slowing the system by reading this file.
+
+2. Writing
+
+ Writing to ppc_htab is not yet allowed.
+
+ Write options to ppc_htab:
+
+ - To set the size of the hash table to 64Kb:
+
+ echo 'size 64' > /dev/ppc_htab
+
+ The size must be a multiple of 64 and must be greater than or equal to
+ 64.
+
+
+
+
+
+
+
+
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen, slshen@lbl.gov