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[Qemu-devel] [PULL 21/23] qcow2: Fix cache-clean-interval documentation
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 21/23] qcow2: Fix cache-clean-interval documentation |
Date: |
Mon, 1 Oct 2018 19:18:59 +0200 |
From: Leonid Bloch <address@hidden>
Fixing cache-clean-interval documentation following the recent change to
a default of 600 seconds on supported plarforms (only Linux currently).
Signed-off-by: Leonid Bloch <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
qapi/block-core.json | 3 ++-
docs/qcow2-cache.txt | 20 ++++++++++----------
qemu-options.hx | 3 ++-
3 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 46dac23d2f..25b8a0e744 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 600, and 0 disables this feature. (since 2.5)
+# is 600 on supporting platforms, and 0 on other
+# platforms. 0 disables this feature. (since 2.5)
#
# @encrypt: Image decryption options. Mandatory for
# encrypted images, except when doing a metadata-only
diff --git a/docs/qcow2-cache.txt b/docs/qcow2-cache.txt
index 59358b816f..c459bf5dd3 100644
--- a/docs/qcow2-cache.txt
+++ b/docs/qcow2-cache.txt
@@ -202,18 +202,18 @@ Reducing the memory usage
It is possible to clean unused cache entries in order to reduce the
memory usage during periods of low I/O activity.
-The parameter "cache-clean-interval" defines an interval (in seconds).
-All cache entries that haven't been accessed during that interval are
-removed from memory.
+The parameter "cache-clean-interval" defines an interval (in seconds),
+after which all the cache entries that haven't been accessed during the
+interval are removed from memory. Setting this parameter to 0 disables this
+feature.
-This example removes all unused cache entries every 15 minutes:
+The following 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 600. Setting it to 0
-disables this feature.
+If unset, the default value for this parameter is 600 on platforms which
+support this functionality, and is 0 (disabled) on other platforms.
-Note that this functionality currently relies on the MADV_DONTNEED
-argument for madvise() to actually free the memory. This is a
-Linux-specific feature, so cache-clean-interval is not supported in
-other systems.
+This functionality currently relies on the MADV_DONTNEED argument for
+madvise() to actually free the memory. This is a Linux-specific feature,
+so cache-clean-interval is not supported on other systems.
diff --git a/qemu-options.hx b/qemu-options.hx
index 52d9d9f06d..f139459e80 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -747,7 +747,8 @@ 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 600. Setting it to 0 disables this feature.
+The default value is 600 on supporting platforms, and 0 on other platforms.
+Setting it to 0 disables this feature.
@item pass-discard-request
Whether discard requests to the qcow2 device should be forwarded to the data
--
2.13.6
- Re: [Qemu-devel] [Qemu-block] [PULL 08/23] file-posix: Forbid trying to change unsupported options during reopen, (continued)
- [Qemu-devel] [PULL 17/23] qcow2: Resize the cache upon image resizing, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 19/23] qcow2: Explicit number replaced by a constant, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 14/23] qcow2: Avoid duplication in setting the refcount cache size, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 18/23] qcow2: Set the default cache-clean-interval to 10 minutes, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 11/23] qcow2: Options' documentation fixes, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 20/23] block-backend: Set werror/rerror defaults in blk_new(), Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 13/23] qcow2: Make sizes more humanly readable, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 12/23] include: Add a lookup table of sizes, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 21/23] qcow2: Fix cache-clean-interval documentation,
Kevin Wolf <=
- [Qemu-devel] [PULL 16/23] qcow2: Increase the default upper limit on the L2 cache size, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 23/23] tests/test-bdrv-drain: Fix too late qemu_event_reset(), Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 22/23] test-replication: Lock AioContext around blk_unref(), Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 15/23] qcow2: Assign the L2 cache relatively to the image size, Kevin Wolf, 2018/10/01
- Re: [Qemu-devel] [PULL 00/23] Block layer patches, Peter Maydell, 2018/10/02