From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752696AbbB1SXu (ORCPT ); Sat, 28 Feb 2015 13:23:50 -0500 Received: from p3plsmtps2ded03.prod.phx3.secureserver.net ([208.109.80.60]:34862 "EHLO p3plsmtps2ded03.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752345AbbB1SXs (ORCPT ); Sat, 28 Feb 2015 13:23:48 -0500 x-originating-ip: 72.167.245.219 From: "K. Y. Srinivasan" To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, vkuznets@redhat.com Cc: "K. Y. Srinivasan" Subject: [PATCH 3/7] Drivers: hv: hv_balloon: refuse to balloon below the floor Date: Sat, 28 Feb 2015 11:39:00 -0800 Message-Id: <1425152344-4953-3-git-send-email-kys@microsoft.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1425152344-4953-1-git-send-email-kys@microsoft.com> References: <1425152321-4914-1-git-send-email-kys@microsoft.com> <1425152344-4953-1-git-send-email-kys@microsoft.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vitaly Kuznetsov When host asks us to balloon up we need to be sure we're not committing suicide by overballooning. Use already existent 'floor' metric as our lowest possible value for free ram. Signed-off-by: Vitaly Kuznetsov Signed-off-by: K. Y. Srinivasan --- drivers/hv/hv_balloon.c | 11 +++++++++++ 1 files changed, 11 insertions(+), 0 deletions(-) diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index 53932b3..c5bb872 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -1138,6 +1138,8 @@ static void balloon_up(struct work_struct *dummy) bool alloc_error; bool done = false; int i; + struct sysinfo val; + unsigned long floor; /* The host balloons pages in 2M granularity. */ WARN_ON_ONCE(num_pages % PAGES_IN_2M != 0); @@ -1148,6 +1150,15 @@ static void balloon_up(struct work_struct *dummy) */ alloc_unit = 512; + si_meminfo(&val); + floor = compute_balloon_floor(); + + /* Refuse to balloon below the floor, keep the 2M granularity. */ + if (val.freeram - num_pages < floor) { + num_pages = val.freeram > floor ? (val.freeram - floor) : 0; + num_pages -= num_pages % PAGES_IN_2M; + } + while (!done) { bl_resp = (struct dm_balloon_response *)send_buffer; memset(send_buffer, 0, PAGE_SIZE); -- 1.7.4.1