diff options
| author | Xishi Qiu <qiuxishi@huawei.com> | 2016-04-28 16:19:11 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-04-28 19:34:04 -0700 |
| commit | 7c88a292dfcd6979e839493ef18d04770eb3bad0 (patch) | |
| tree | 9e491f3bbb62f99b725af5a633112043ade07248 /Documentation/sysctl/vm.txt | |
| parent | 33334e25769c6ad69b983379578f42581d99a2f9 (diff) | |
Documentation/sysctl/vm.txt: update numa_zonelist_order description
Commit 3193913ce62c ("mm: page_alloc: default node-ordering on 64-bit
NUMA, zone-ordering on 32-bit") changes the default value of
numa_zonelist_order. Update the document.
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/sysctl/vm.txt')
| -rw-r--r-- | Documentation/sysctl/vm.txt | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index cb0368459da3..34a5fece3121 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -581,15 +581,16 @@ Specify "[Nn]ode" for node order "Zone Order" orders the zonelists by zone type, then by node within each zone. Specify "[Zz]one" for zone order. -Specify "[Dd]efault" to request automatic configuration. Autoconfiguration -will select "node" order in following case. -(1) if the DMA zone does not exist or -(2) if the DMA zone comprises greater than 50% of the available memory or -(3) if any node's DMA zone comprises greater than 70% of its local memory and - the amount of local memory is big enough. - -Otherwise, "zone" order will be selected. Default order is recommended unless -this is causing problems for your system/application. +Specify "[Dd]efault" to request automatic configuration. + +On 32-bit, the Normal zone needs to be preserved for allocations accessible +by the kernel, so "zone" order will be selected. + +On 64-bit, devices that require DMA32/DMA are relatively rare, so "node" +order will be selected. + +Default order is recommended unless this is causing problems for your +system/application. ============================================================== |