Pull release into acpica branch

[linux-2.6] / Documentation / sysctl / vm.txt

diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index 2f1aae32a5d9dfc2c0f71bb0400ce4a714d49c07..391dd64363e75b560f68bdd69879946b07cf03da 100644 (file)
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -26,12 +26,14 @@ Currently, these files are in /proc/sys/vm:
 - min_free_kbytes
 - laptop_mode
 - block_dump
+- drop-caches
+- zone_reclaim_mode
 
 ==============================================================
 
 dirty_ratio, dirty_background_ratio, dirty_expire_centisecs,
 dirty_writeback_centisecs, vfs_cache_pressure, laptop_mode,
-block_dump, swap_token_timeout:
+block_dump, swap_token_timeout, drop-caches:
 
 See Documentation/filesystems/proc.txt
 
@@ -102,3 +104,37 @@ This is used to force the Linux VM to keep a minimum number
 of kilobytes free.  The VM uses this number to compute a pages_min
 value for each lowmem zone in the system.  Each lowmem zone gets 
 a number of reserved free pages based proportionally on its size.
+
+==============================================================
+
+percpu_pagelist_fraction
+
+This is the fraction of pages at most (high mark pcp->high) in each zone that
+are allocated for each per cpu page list.  The min value for this is 8.  It
+means that we don't allow more than 1/8th of pages in each zone to be
+allocated in any single per_cpu_pagelist.  This entry only changes the value
+of hot per cpu pagelists.  User can specify a number like 100 to allocate
+1/100th of each zone to each per cpu page list.
+
+The batch value of each per cpu pagelist is also updated as a result.  It is
+set to pcp->high/4.  The upper limit of batch is (PAGE_SHIFT * 8)
+
+The initial value is zero.  Kernel does not use this value at boot time to set
+the high water marks for each per cpu page list.
+
+===============================================================
+
+zone_reclaim_mode:
+
+This is set during bootup to 1 if it is determined that pages from
+remote zones will cause a significant performance reduction. The
+page allocator will then reclaim easily reusable pages (those page
+cache pages that are currently not used) before going off node.
+
+The user can override this setting. It may be beneficial to switch
+off zone reclaim if the system is used for a file server and all
+of memory should be used for caching files from disk.
+
+It may be beneficial to switch this on if one wants to do zone
+reclaim regardless of the numa distances in the system.
+