From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03870ECE563 for ; Tue, 18 Sep 2018 06:41:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA42E20867 for ; Tue, 18 Sep 2018 06:41:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BA42E20867 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=vmware.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729496AbeIRMMZ (ORCPT ); Tue, 18 Sep 2018 08:12:25 -0400 Received: from ex13-edg-ou-002.vmware.com ([208.91.0.190]:36971 "EHLO EX13-EDG-OU-002.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727123AbeIRMLf (ORCPT ); Tue, 18 Sep 2018 08:11:35 -0400 Received: from sc9-mailhost3.vmware.com (10.113.161.73) by EX13-EDG-OU-002.vmware.com (10.113.208.156) with Microsoft SMTP Server id 15.0.1156.6; Mon, 17 Sep 2018 23:39:56 -0700 Received: from sc2-haas01-esx0118.eng.vmware.com (sc2-haas01-esx0118.eng.vmware.com [10.172.44.118]) by sc9-mailhost3.vmware.com (Postfix) with ESMTP id D122B407E6; Mon, 17 Sep 2018 23:40:19 -0700 (PDT) From: Nadav Amit To: Arnd Bergmann , Greg Kroah-Hartman CC: , Nadav Amit Subject: [PATCH 08/19] vmw_balloon: refactor change size from vmballoon_work Date: Mon, 17 Sep 2018 23:38:42 -0700 Message-ID: <20180918063853.198332-9-namit@vmware.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180918063853.198332-1-namit@vmware.com> References: <20180918063853.198332-1-namit@vmware.com> MIME-Version: 1.0 Content-Type: text/plain Received-SPF: None (EX13-EDG-OU-002.vmware.com: namit@vmware.com does not designate permitted sender hosts) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The required change in the balloon size is currently computed in vmballoon_work(), vmballoon_inflate() and vmballoon_deflate(). Refactor it to simplify the next patches. Reviewed-by: Xavier Deguillard Signed-off-by: Nadav Amit --- drivers/misc/vmw_balloon.c | 74 ++++++++++++++++++++++++++------------ 1 file changed, 51 insertions(+), 23 deletions(-) diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c index 74fff1e314a7..aafd087809e9 100644 --- a/drivers/misc/vmw_balloon.c +++ b/drivers/misc/vmw_balloon.c @@ -632,6 +632,36 @@ static void vmballoon_add_page(struct vmballoon *b, int idx, struct page *p) b->page = p; } +/** + * vmballoon_change - retrieve the required balloon change + * + * @b: pointer for the balloon. + * + * Return: the required change for the balloon size. A positive number + * indicates inflation, a negative number indicates a deflation. + */ +static int64_t vmballoon_change(struct vmballoon *b) +{ + int64_t size, target; + + size = b->size; + target = b->target; + + /* + * We must cast first because of int sizes + * Otherwise we might get huge positives instead of negatives + */ + + if (b->reset_required) + return 0; + + /* consider a 2MB slack on deflate, unless the balloon is emptied */ + if (target < size && size - target < HPAGE_PMD_NR && target != 0) + return 0; + + return target - size; +} + /* * Inflate the balloon towards its target size. Note that we try to limit * the rate of allocation to make sure we are not choking the rest of the @@ -643,8 +673,6 @@ static void vmballoon_inflate(struct vmballoon *b) int error = 0; bool is_2m_pages; - pr_debug("%s - size: %d, target %d\n", __func__, b->size, b->target); - /* * First try NOSLEEP page allocations to inflate balloon. * @@ -666,11 +694,8 @@ static void vmballoon_inflate(struct vmballoon *b) */ is_2m_pages = b->supported_page_sizes == VMW_BALLOON_NUM_PAGE_SIZES; - pr_debug("%s - goal: %d", __func__, b->target - b->size); - - while (!b->reset_required && - b->size + num_pages * vmballoon_page_size(is_2m_pages) - < b->target) { + while ((int64_t)(num_pages * vmballoon_page_size(is_2m_pages)) < + vmballoon_change(b)) { struct page *page; STATS_INC(b->stats.alloc[is_2m_pages]); @@ -741,8 +766,6 @@ static void vmballoon_deflate(struct vmballoon *b) { unsigned is_2m_pages; - pr_debug("%s - size: %d, target %d\n", __func__, b->size, b->target); - /* free pages to reach target */ for (is_2m_pages = 0; is_2m_pages < b->supported_page_sizes; is_2m_pages++) { @@ -752,11 +775,9 @@ static void vmballoon_deflate(struct vmballoon *b) &b->page_sizes[is_2m_pages]; list_for_each_entry_safe(page, next, &page_size->pages, lru) { - if (b->reset_required || - (b->target > 0 && - b->size - num_pages - * vmballoon_page_size(is_2m_pages) - < b->target + vmballoon_page_size(true))) + if ((int64_t)(num_pages * + vmballoon_page_size(is_2m_pages)) >= + -vmballoon_change(b)) break; list_del(&page->lru); @@ -920,28 +941,35 @@ static void vmballoon_reset(struct vmballoon *b) pr_err("failed to send guest ID to the host\n"); } -/* - * Balloon work function: reset protocol, if needed, get the new size and - * adjust balloon as needed. Repeat in 1 sec. +/** + * vmballoon_work - periodic balloon worker for reset, inflation and deflation. + * + * @work: pointer to the &work_struct which is provided by the workqueue. + * + * Resets the protocol if needed, gets the new size and adjusts balloon as + * needed. Repeat in 1 sec. */ static void vmballoon_work(struct work_struct *work) { struct delayed_work *dwork = to_delayed_work(work); struct vmballoon *b = container_of(dwork, struct vmballoon, dwork); + int64_t change = 0; STATS_INC(b->stats.timer); if (b->reset_required) vmballoon_reset(b); - if (!b->reset_required && vmballoon_send_get_target(b)) { - unsigned long target = b->target; + if (vmballoon_send_get_target(b)) + change = vmballoon_change(b); + + if (change != 0) { + pr_debug("%s - size: %u, target %u", __func__, + b->size, b->target); - /* update target, adjust size */ - if (b->size < target) + if (change > 0) vmballoon_inflate(b); - else if (target == 0 || - b->size > target + vmballoon_page_size(true)) + else /* (change < 0) */ vmballoon_deflate(b); } -- 2.17.1