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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 AD75DC76196 for ; Thu, 18 Jul 2019 05:51:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6C2E521855 for ; Thu, 18 Jul 2019 05:51:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6C2E521855 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C739F6B0005; Thu, 18 Jul 2019 01:51:36 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BFD3A8E0001; Thu, 18 Jul 2019 01:51:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A9F6A6B000A; Thu, 18 Jul 2019 01:51:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-pl1-f197.google.com (mail-pl1-f197.google.com [209.85.214.197]) by kanga.kvack.org (Postfix) with ESMTP id 6ED046B0005 for ; Thu, 18 Jul 2019 01:51:36 -0400 (EDT) Received: by mail-pl1-f197.google.com with SMTP id 91so13321316pla.7 for ; Wed, 17 Jul 2019 22:51:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:message-id :date:from:user-agent:mime-version:to:cc:subject:references :in-reply-to:content-transfer-encoding; bh=bJ+P6l4sBWFG4da91ExsiJIOILHZRWwkDB2B+itWlwI=; b=GCjubvsD4QKlXy+P0rkd7P4IQaKvKswlVDLLHVHe4f8MUqj3iJULKMUZYZmaB9Wj6J uOKY2MsbL6Ut9o0bC7INnen/rIpRkkRwpaSQXCrEmTkxWWPqkZNdmrbLurwr+oWZbqis 4xn4FASb4Vb8TaA/iP5vUk1ZLCyxvwoSdsbwfr1kFp/9ax+eCeNgPX7btSvL8QMfRt11 rSkv7IinBj8LEXOHC9HX8lznNkuXdeVgo/A0QEy3dteg+2rzPWCeRSA059F9uEb81fem LAlCRgk5ZNKlI9X5boY4maOv1oFy0L93Bt6qCB9JGDGWR7cJBblSjEpX7erroS9mprBr 4/dA== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of wei.w.wang@intel.com designates 134.134.136.20 as permitted sender) smtp.mailfrom=wei.w.wang@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Gm-Message-State: APjAAAWiKdRQbTGixbTozCzBzbTtv4RRVctLoR08Pf+bKHVVVs1bc6aW SQaGJKJWjd0mIJQHNlhR85j5xW1aqbyNDkZ3u3JDS1/ykHVWtV2LKWSr+gzBVBjDDcPmqHwsRrC AheCL/eJAE5SKVMFlsQtgv9qyC4+nQzEoF4Bj7XahEgG6mep53nv94cbbdVj+qr5K7g== X-Received: by 2002:a17:902:f301:: with SMTP id gb1mr47227919plb.292.1563429096002; Wed, 17 Jul 2019 22:51:36 -0700 (PDT) X-Google-Smtp-Source: APXvYqy6GxrMic7DMv2XTAI+k5V64n7Axo3QOkzNDqqAk0M2DSWJy+X2b35g7lKvmhvlEDbnmj1O X-Received: by 2002:a17:902:f301:: with SMTP id gb1mr47227868plb.292.1563429095346; Wed, 17 Jul 2019 22:51:35 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1563429095; cv=none; d=google.com; s=arc-20160816; b=PpLeP1tvV0r6vuGed0qPzGUC1bdg6U2xk9WsrG3WX+NxtzO50N4MYAlJFmgvu2NpBl ZkA6QzgV1bXYAfwYXefpJC5ce7rs3tVW4Kwj3aNLWjleUFXU47TDhk2njIUf8BfM+pWu m7BdrrEPdz3Kz07t//u3LfuE1E9M6xN27bGZi2pQSdtvz3Z04fX1Iz3hLBivto5yYvnl UxfB2abs94/z1cAZfAlkxjjkmYeSqf0OGiQP3PnDfwEcVqUcbXuu/ooVsJljIcGeTp3R CAuz04oEezLsR9q6aww8Kn5ToKIqIrPEueUYgrfdCA2xQwX9FjKz2aXQ8woXmNim2HQw w6sg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:in-reply-to:references:subject:cc:to :mime-version:user-agent:from:date:message-id; bh=bJ+P6l4sBWFG4da91ExsiJIOILHZRWwkDB2B+itWlwI=; b=wQZjLb32gGwZra/v4ScVE2y6VAI7g8FpEjaptRywqnCWZoC23dYuIeWWWb+b6dO+lL oKqzs41RkOxcMdB1riEgHzlyECGMvIRslfQCI/vAeH8bxdCK3mG94AHhf113m38B0uLz oJOl60XEG2uCZC2ZGNSU2XETmuEYoX1GNIE+ByvCPr19WPLf5T0Ip6FddI3N+clQlgXn bbto+IfucX9j73rlG+yN1erSuYGQga6pRZC3ZKk14uBT96lnILXkxqyGOXw5jhnBVArX +1jAQLpZZdt9jqcJJ0b/GTvO0B2v5ZyQteUOFV+Rbz76YMZrhGUePY8AZyUXeAmHjla9 qbBg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of wei.w.wang@intel.com designates 134.134.136.20 as permitted sender) smtp.mailfrom=wei.w.wang@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTPS id o8si7229388pgj.239.2019.07.17.22.51.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 17 Jul 2019 22:51:35 -0700 (PDT) Received-SPF: pass (google.com: domain of wei.w.wang@intel.com designates 134.134.136.20 as permitted sender) client-ip=134.134.136.20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of wei.w.wang@intel.com designates 134.134.136.20 as permitted sender) smtp.mailfrom=wei.w.wang@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Jul 2019 22:51:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,276,1559545200"; d="scan'208";a="367248561" Received: from unknown (HELO [10.239.13.7]) ([10.239.13.7]) by fmsmga006.fm.intel.com with ESMTP; 17 Jul 2019 22:51:30 -0700 Message-ID: <5D300A32.4090300@intel.com> Date: Thu, 18 Jul 2019 13:57:06 +0800 From: Wei Wang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: "Michael S. Tsirkin" CC: Alexander Duyck , Nitesh Narayan Lal , kvm list , David Hildenbrand , "Hansen, Dave" , LKML , linux-mm , Andrew Morton , Yang Zhang , "pagupta@redhat.com" , Rik van Riel , Konrad Rzeszutek Wilk , "lcapitulino@redhat.com" , Andrea Arcangeli , Paolo Bonzini , "Williams, Dan J" , Alexander Duyck Subject: Re: use of shrinker in virtio balloon free page hinting References: <20190717071332-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F73E16D4B2@shsmsx102.ccr.corp.intel.com> <20190718000434-mutt-send-email-mst@kernel.org> In-Reply-To: <20190718000434-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 07/18/2019 12:13 PM, Michael S. Tsirkin wrote: > > It makes sense for pages in the balloon (requested by hypervisor). > However free page hinting can freeze up lots of memory for its own > internal reasons. It does not make sense to ask hypervisor > to set flags in order to fix internal guest issues. Sounds reasonable to me. Probably we could move the flag check to shrinker_count and shrinker_scan as a reclaiming condition for ballooning pages only? > > Right. But that does not include the pages in the hint vq, > which could be a significant amount of memory. I think it includes, as vb->num_free_page_blocks records the total number of free page blocks that balloon has taken from mm. For shrink_free_pages, it calls return_free_pages_to_mm, which pops pages from vb->free_page_list (this is the list where pages get enlisted after they are put to the hint vq, see get_free_page_and_send). > > >>> - if free pages are being reported, pages freed >>> by shrinker will just get re-allocated again >> fill_balloon will re-try the allocation after sleeping 200ms once allocation fails. > Even if ballon was never inflated, if shrinker frees some memory while > we are hinting, hint vq will keep going and allocate it back without > sleeping. Still see get_free_page_and_send. -EINTR is returned when page allocation fails, and reporting ends then. Shrinker is called on system memory pressure. On memory pressure get_free_page_and_send will fail memory allocation, so it stops allocating more. Best, Wei