From 5e5ad26daad9372b9276b18c5b773528b8239c31 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 6 Dec 2018 17:12:37 +0000 Subject: [PATCH 12/15] qcow2: Set the default cache-clean-interval to 10 minutes RH-Author: Kevin Wolf Message-id: <20181206171240.5674-13-kwolf@redhat.com> Patchwork-id: 83288 O-Subject: [RHEL-8.0 qemu-kvm PATCH 12/15] qcow2: Set the default cache-clean-interval to 10 minutes Bugzilla: 1656507 RH-Acked-by: Max Reitz RH-Acked-by: John Snow RH-Acked-by: Stefan Hajnoczi From: Leonid Bloch 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 Reviewed-by: Alberto Garcia Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf (cherry picked from commit e957b50b8daecfc39a1ac09855b0eacb6edfd328) Signed-off-by: Kevin Wolf Signed-off-by: Danilo C. L. de Paula --- block/qcow2.c | 2 +- block/qcow2.h | 4 +++- docs/qcow2-cache.txt | 4 ++-- qapi/block-core.json | 3 ++- qemu-options.hx | 2 +- 5 files changed, 9 insertions(+), 6 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index 72f1ea8..acd076c 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -940,7 +940,7 @@ 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 6c6c742..29b041c 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -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 #define DEFAULT_CLUSTER_SIZE S_64KiB - #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts" #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request" #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot" diff --git a/docs/qcow2-cache.txt b/docs/qcow2-cache.txt index 1fcc065..59358b8 100644 --- a/docs/qcow2-cache.txt +++ 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. 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 a6c3977..5318c9b 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -2867,7 +2867,8 @@ # # @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 e3f4e43..05fabf3 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 -- 1.8.3.1