From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752501AbbBSQ1Y (ORCPT ); Thu, 19 Feb 2015 11:27:24 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44237 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752404AbbBSQ1W (ORCPT ); Thu, 19 Feb 2015 11:27:22 -0500 From: Vitaly Kuznetsov To: "K. Y. Srinivasan" , devel@linuxdriverproject.org Cc: Haiyang Zhang , linux-kernel@vger.kernel.org, Dexuan Cui Subject: [PATCH 2/2] Drivers: hv: hv_balloon: refuse to balloon below the floor Date: Thu, 19 Feb 2015 17:27:10 +0100 Message-Id: <1424363230-3758-3-git-send-email-vkuznets@redhat.com> In-Reply-To: <1424363230-3758-1-git-send-email-vkuznets@redhat.com> References: <1424363230-3758-1-git-send-email-vkuznets@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- drivers/hv/hv_balloon.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index e4b4454..3292e97 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); -- 1.9.3