The default cache-clean-interval is set to 10 minutes, in order to lower
the overhead of the qcow2 caches (before the default was 0, i.e.
disabled).
Signed-off-by: Leonid Bloch <lbl...@janustech.com>
Reviewed-by: Alberto Garcia <be...@igalia.com>
---
block/qcow2.c | 2 +-
block/qcow2.h | 1 +
docs/qcow2-cache.txt | 4 ++--
qapi/block-core.json | 3 ++-
qemu-options.hx | 2 +-
5 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index ba4dfae735..b4f291765b 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -944,7 +944,7 @@ static int qcow2_update_options_prepare(BlockDriverState
*bs,
/* New interval for cache cleanup timer */
r->cache_clean_interval =
qemu_opt_get_number(opts, QCOW2_OPT_CACHE_CLEAN_INTERVAL,
- s->cache_clean_interval);
+ DEFAULT_CACHE_CLEAN_INTERVAL);
#ifndef CONFIG_LINUX
if (r->cache_clean_interval != 0) {
error_setg(errp, QCOW2_OPT_CACHE_CLEAN_INTERVAL
diff --git a/block/qcow2.h b/block/qcow2.h
index d77a31d932..587b053453 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -77,6 +77,7 @@
#define DEFAULT_CLUSTER_SIZE 65536
+#define DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */
#define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
#define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
diff --git a/docs/qcow2-cache.txt b/docs/qcow2-cache.txt
index 6ad1081d1a..684147ad45 100644
--- a/docs/qcow2-cache.txt
+++ b/docs/qcow2-cache.txt
@@ -204,8 +204,8 @@ This example removes all unused cache entries every 15
minutes:
-drive file=hd.qcow2,cache-clean-interval=900
-If unset, the default value for this parameter is 0 and it disables
-this feature.
+If unset, the default value for this parameter is 600. Setting it to 0
+disables this feature.
Note that this functionality currently relies on the MADV_DONTNEED
argument for madvise() to actually free the memory. This is a
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 5b9084a394..9a6a708a37 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -2830,7 +2830,8 @@
#
# @cache-clean-interval: clean unused entries in the L2 and refcount
# caches. The interval is in seconds. The default value
-# is 0 and it disables this feature (since 2.5)
+# is 600, and 0 disables this feature. (since 2.5)
+#
# @encrypt: Image decryption options. Mandatory for
# encrypted images, except when doing a metadata-only
# probe of the image. (since 2.10)
diff --git a/qemu-options.hx b/qemu-options.hx
index 4c44cdbc23..6abf3631ec 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -767,7 +767,7 @@ it which is not used for the L2 cache)
@item cache-clean-interval
Clean unused entries in the L2 and refcount caches. The interval is in seconds.
-The default value is 0 and it disables this feature.
+The default value is 600. Setting it to 0 disables this feature.
@item pass-discard-request
Whether discard requests to the qcow2 device should be forwarded to the data
--
2.17.1
