On 9/26/18 11:04 AM, Leonid Bloch wrote:
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).
* For non-Linux platforms the default is kept at 0, because
cache-clean-interval is not supported there yet.
Signed-off-by: Leonid Bloch <lbl...@janustech.com>
Reviewed-by: Alberto Garcia <be...@igalia.com>
Reviewed-by: Kevin Wolf <kw...@redhat.com>
---
@@ -76,13 +76,15 @@
#ifdef CONFIG_LINUX
#define DEFAULT_L2_CACHE_MAX_SIZE S_32MiB
+#define DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */
#else
#define DEFAULT_L2_CACHE_MAX_SIZE S_8MiB
+/* Cache clean interval is currently available only on Linux, so must be 0 */
+#define DEFAULT_CACHE_CLEAN_INTERVAL 0
#endif
+++ b/docs/qcow2-cache.txt
@@ -210,8 +210,8 @@ 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.
Should this wording mention that the non-zero default is only on Linux
(or rather, only on platforms where a non-zero value makes a difference)?
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 ac3b48ee54..46dac23d2f 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -2895,7 +2895,8 @@
#
# @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)
and again here
+#
# @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 14aee78c6c..52d9d9f06d 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -747,7 +747,7 @@ 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.
and here?
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
