From patchwork Mon Oct 1 17:18:59 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 977331 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 42P8bJ3gqZz9sBj for ; Tue, 2 Oct 2018 03:36:28 +1000 (AEST) Received: from localhost ([::1]:39921 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g727N-0006f4-5K for incoming@patchwork.ozlabs.org; Mon, 01 Oct 2018 13:36:25 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57948) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g71rE-0002YH-EG 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 1g71rC-0007Ki-Ao for qemu-devel@nongnu.org; Mon, 01 Oct 2018 13:19:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47252) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1g71r7-0007Bq-Qo; Mon, 01 Oct 2018 13:19:38 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A2DB9307C716; Mon, 1 Oct 2018 17:19:36 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-116-246.ams2.redhat.com [10.36.116.246]) by smtp.corp.redhat.com (Postfix) with ESMTP id 866D678915; Mon, 1 Oct 2018 17:19:35 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Mon, 1 Oct 2018 19:18:59 +0200 Message-Id: <20181001171901.11004-22-kwolf@redhat.com> In-Reply-To: <20181001171901.11004-1-kwolf@redhat.com> References: <20181001171901.11004-1-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Mon, 01 Oct 2018 17:19:36 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 21/23] qcow2: Fix cache-clean-interval documentation X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Leonid Bloch 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 Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- 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