From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47511) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fiKmL-00055E-5s for qemu-devel@nongnu.org; Wed, 25 Jul 2018 10:28:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fiKmI-0000AZ-5L for qemu-devel@nongnu.org; Wed, 25 Jul 2018 10:28:37 -0400 From: Leonid Bloch Date: Wed, 25 Jul 2018 17:27:56 +0300 Message-Id: <20180725142758.9980-3-lbloch@janustech.com> In-Reply-To: <20180725142758.9980-1-lbloch@janustech.com> References: <20180725142758.9980-1-lbloch@janustech.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [PATCH v5 2/4 for-3.0] qcow2: Options' documentation fixes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, Kevin Wolf , Max Reitz , Eric Blake , Leonid Bloch Signed-off-by: Leonid Bloch --- docs/qcow2-cache.txt | 3 +++ qemu-options.hx | 10 ++++++---- 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/docs/qcow2-cache.txt b/docs/qcow2-cache.txt index 8a09a5cc5f..3673f2be0e 100644 --- a/docs/qcow2-cache.txt +++ b/docs/qcow2-cache.txt @@ -130,6 +130,9 @@ There are a few things that need to be taken into account: memory as possible to the L2 cache before increasing the refcount cache size. +- At most two of "l2-cache-size", "refcount-cache-size", and "cache-size" + can be set simultaneously. + Unlike L2 tables, refcount blocks are not used during normal I/O but only during allocations and internal snapshots. In most cases they are accessed sequentially (even during random guest I/O) so increasing the diff --git a/qemu-options.hx b/qemu-options.hx index b1bf0f485f..13ece21cb6 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -752,15 +752,17 @@ image file) @item cache-size The maximum total size of the L2 table and refcount block caches in bytes -(default: 1048576 bytes or 8 clusters, whichever is larger) @item l2-cache-size -The maximum size of the L2 table cache in bytes -(default: 4/5 of the total cache size) +The maximum size of the L2 table cache. +(default: if cache-size is not defined - 1048576 bytes or 8 clusters, whichever +is larger; otherwise, as large as possible or needed within the cache-size, +while permitting the requested or the minimal refcount cache size) @item refcount-cache-size The maximum size of the refcount block cache in bytes -(default: 1/5 of the total cache size) +(default: 4 times the cluster size, or any portion of the cache-size, if it is +specified and large enough, left over after allocating the full L2 cache) @item cache-clean-interval Clean unused entries in the L2 and refcount caches. The interval is in seconds. -- 2.14.1