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authorGabriel <g2p.code+bcache@gmail.com>2013-04-24 19:51:02 +0200
committerKent Overstreet <koverstreet@google.com>2013-05-15 00:42:52 -0700
commitfe0a797a6b42d9ad0ed063eaef705da1eb3c8147 (patch)
treeabc5916e5b4ce166248748cdd9a8624747eaf1b1 /Documentation/bcache.txt
parentbbb1c3b5ae6c6286a5e018786be88f126d769543 (diff)
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bcache: clarify free/available/unused space
Don't describe bcache_available_percent as free space but as non-writeback space. Describe priority_stats in more detail and point to that for total bcache occupation. Signed-off-by: Gabriel de Perthuis <g2p.code+bcache@gmail.com> Signed-off-by: Kent Overstreet <koverstreet@google.com>
Diffstat (limited to 'Documentation/bcache.txt')
-rw-r--r--Documentation/bcache.txt12
1 files changed, 9 insertions, 3 deletions
diff --git a/Documentation/bcache.txt b/Documentation/bcache.txt
index 77db8809bd96..b3a7e7d384f6 100644
--- a/Documentation/bcache.txt
+++ b/Documentation/bcache.txt
@@ -319,7 +319,10 @@ cache<0..n>
Symlink to each of the cache devices comprising this cache set.
cache_available_percent
- Percentage of cache device free.
+ Percentage of cache device which doesn't contain dirty data, and could
+ potentially be used for writeback. This doesn't mean this space isn't used
+ for clean cached data; the unused statistic (in priority_stats) is typically
+ much lower.
clear_stats
Clears the statistics associated with this cache
@@ -423,8 +426,11 @@ nbuckets
Total buckets in this cache
priority_stats
- Statistics about how recently data in the cache has been accessed. This can
- reveal your working set size.
+ Statistics about how recently data in the cache has been accessed.
+ This can reveal your working set size. Unused is the percentage of
+ the cache that doesn't contain any data. Metadata is bcache's
+ metadata overhead. Average is the average priority of cache buckets.
+ Next is a list of quantiles with the priority threshold of each.
written
Sum of all data that has been written to the cache; comparison with
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