From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57931) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g71rE-0002Xs-1N for qemu-devel@nongnu.org; Mon, 01 Oct 2018 13:19:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g71rB-0007Jq-TM for qemu-devel@nongnu.org; Mon, 01 Oct 2018 13:19:43 -0400 From: Kevin Wolf Date: Mon, 1 Oct 2018 19:18:56 +0200 Message-Id: <20181001171901.11004-19-kwolf@redhat.com> In-Reply-To: <20181001171901.11004-1-kwolf@redhat.com> References: <20181001171901.11004-1-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 18/23] qcow2: Set the default cache-clean-interval to 10 minutes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org 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 --- qapi/block-core.json | 3 ++- docs/qcow2-cache.txt | 4 ++-- block/qcow2.h | 4 +++- block/qcow2.c | 2 +- qemu-options.hx | 2 +- 5 files changed, 9 insertions(+), 6 deletions(-) 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) +# # @encrypt: Image decryption options. Mandatory for # encrypted images, except when doing a metadata-only # probe of the image. (since 2.10) diff --git a/docs/qcow2-cache.txt b/docs/qcow2-cache.txt index 1fcc0658b2..59358b816f 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/block/qcow2.h b/block/qcow2.h index 0f0e3534bf..ba430316b9 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/block/qcow2.c b/block/qcow2.c index 20b5093269..95e1c98daa 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/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. @item pass-discard-request Whether discard requests to the qcow2 device should be forwarded to the data -- 2.13.6