Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
---
Documentation/vm/zsmalloc.txt | 60 ++++++++++++++++++++++++++-----------------
1 file changed, 36 insertions(+), 24 deletions(-)
diff --git a/Documentation/vm/zsmalloc.txt b/Documentation/vm/zsmalloc.txt
index 64ed63c..6e79893 100644
--- a/Documentation/vm/zsmalloc.txt
+++ b/Documentation/vm/zsmalloc.txt
@@ -1,5 +1,8 @@
+.. _zsmalloc:
+
+========
zsmalloc
---------
+========
This allocator is designed for use with zram. Thus, the allocator is
supposed to work well under low memory conditions. In particular, it
@@ -31,40 +34,49 @@ be mapped using zs_map_object() to get a usable pointer and subsequently
unmapped using zs_unmap_object().
stat
-----
+====
With CONFIG_ZSMALLOC_STAT, we could see zsmalloc internal information via
-/sys/kernel/debug/zsmalloc/<user name>. Here is a sample of stat output:
+``/sys/kernel/debug/zsmalloc/<user name>``. Here is a sample of stat output::
-# cat /sys/kernel/debug/zsmalloc/zram0/classes
+ # cat /sys/kernel/debug/zsmalloc/zram0/classes
class size almost_full almost_empty obj_allocated obj_used pages_used pages_per_zspage
- ..
- ..
+ ...
+ ...
9 176 0 1 186 129 8 4
10 192 1 0 2880 2872 135 3
11 208 0 1 819 795 42 2
12 224 0 1 219 159 12 4
- ..
- ..
+ ...
+ ...
+
+class
+ index
+size
+ object size zspage stores
+almost_empty
+ the number of ZS_ALMOST_EMPTY zspages(see below)
+almost_full
+ the number of ZS_ALMOST_FULL zspages(see below)
+obj_allocated
+ the number of objects allocated
+obj_used
+ the number of objects allocated to the user
+pages_used
+ the number of pages allocated for the class
+pages_per_zspage
+ the number of 0-order pages to make a zspage
-class: index
-size: object size zspage stores
-almost_empty: the number of ZS_ALMOST_EMPTY zspages(see below)
-almost_full: the number of ZS_ALMOST_FULL zspages(see below)
-obj_allocated: the number of objects allocated
-obj_used: the number of objects allocated to the user
-pages_used: the number of pages allocated for the class
-pages_per_zspage: the number of 0-order pages to make a zspage
+We assign a zspage to ZS_ALMOST_EMPTY fullness group when n <= N / f, where
-We assign a zspage to ZS_ALMOST_EMPTY fullness group when:
- n <= N / f, where
-n = number of allocated objects
-N = total number of objects zspage can store
-f = fullness_threshold_frac(ie, 4 at the moment)
+* n = number of allocated objects
+* N = total number of objects zspage can store
+* f = fullness_threshold_frac(ie, 4 at the moment)
Similarly, we assign zspage to:
- ZS_ALMOST_FULL when n > N / f
- ZS_EMPTY when n == 0
- ZS_FULL when n == N
+
+* ZS_ALMOST_FULL when n > N / f
+* ZS_EMPTY when n == 0
+* ZS_FULL when n == N
--
2.7.4
