From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:33011)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <kwolf@redhat.com>) id 1Yzk03-0000ah-LD
	for qemu-devel@nongnu.org; Tue, 02 Jun 2015 07:04:52 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <kwolf@redhat.com>) id 1Yzk02-0005qQ-O3
	for qemu-devel@nongnu.org; Tue, 02 Jun 2015 07:04:51 -0400
Date: Tue, 2 Jun 2015 13:04:42 +0200
From: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20150602110442.GK3765@noname.str.redhat.com>
References: <cover.1432891306.git.berto@igalia.com>
	<7a6512906476a36bc7c88f92d4e5eb882309f5f3.1432891306.git.berto@igalia.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <7a6512906476a36bc7c88f92d4e5eb882309f5f3.1432891306.git.berto@igalia.com>
Subject: Re: [Qemu-devel] [PATCH 2/3] qcow2: add option to clean unused
 cache entries after some time
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Alberto Garcia <berto@igalia.com>
Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>, Max Reitz <mreitz@redhat.com>

Am 29.05.2015 um 11:24 hat Alberto Garcia geschrieben:
> This adds a new 'cache-clean-interval' option that cleans all qcow2
> cache entries that haven't been used in a certain interval, given in
> seconds.
> 
> This allows setting a large L2 cache size so it can handle scenarios
> with lots of I/O and at the same time use little memory during periods
> of inactivity.
> 
> This feature currently relies on MADV_DONTNEED to free that memory, so
> it is not useful in systems that don't follow that behavior.
> 
> Signed-off-by: Alberto Garcia <berto@igalia.com>
> Reviewed-by: Max Reitz <mreitz@redhat.com>

> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index 863ffea..f42338d 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -1538,6 +1538,9 @@
>  # @refcount-cache-size:   #optional the maximum size of the refcount block cache
>  #                         in bytes (since 2.2)
>  #
> +# @cache-clean-interval:  #optional clean unused entries in the L2 and refcount
> +#                         caches. The interval is in seconds (since 2.4)

Should add that 0 means disabling the cleaning, and 0 is the default.

Kevin