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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 368EEC10F03 for ; Mon, 25 Mar 2019 15:37:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0C2E520879 for ; Mon, 25 Mar 2019 15:37:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729283AbfCYPh0 (ORCPT ); Mon, 25 Mar 2019 11:37:26 -0400 Received: from mail-qk1-f196.google.com ([209.85.222.196]:39474 "EHLO mail-qk1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725795AbfCYPh0 (ORCPT ); Mon, 25 Mar 2019 11:37:26 -0400 Received: by mail-qk1-f196.google.com with SMTP id c189so5580649qke.6 for ; Mon, 25 Mar 2019 08:37:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=ULt4UAznv66zNgUvqi5PYm74n/6JzDtsJmpKbhGf0Hc=; b=VvggE18u1AdFUTV8LXELecgSKU3VGor0t6tBzSjgIlpBgGkAYY+FnzphQJlMqAYB1T xB+D17aAjq8swQ430pyQb5tzoI0kZLLMDcNhFSozge9fY8JJ4OTSQpjO2P76MGcz2Yn9 UkHz24y8wymMwPyBXDq6LCDY/I0IUGXKFnO9sptsrqr/ad8yTKnEC4x2OQXaltS+1daj XsAqeudcZvHX3qQYVIHNNWDAW4SQ7+EiouRGsfNmuLQIkPRENMyO3zQVnSY88poofMcq 3bQ/pf4Hpbup/gLax5Q1SDFTb7Ji9gmCRBwGD4g7Rl90XZQnYU483Q606BtD0vgIMBzc XSlg== X-Gm-Message-State: APjAAAXb6xVCd02IQw9VZoLXFtCn/4G9gXdYr4z/eHv4Y/ZITS/H3Ha3 XtOCMIP5sw0cqF9LG/JDNorflQ== X-Google-Smtp-Source: APXvYqzEUyn4wi4Muptc2YOpiuM7Xps1sZy26/sOBF6ZgKXmq1Rh2mOG+RfvwzCK/Bg9K1n8TZ90Nw== X-Received: by 2002:a37:4dc5:: with SMTP id a188mr19611207qkb.181.1553528245451; Mon, 25 Mar 2019 08:37:25 -0700 (PDT) Received: from redhat.com (pool-173-76-246-42.bstnma.fios.verizon.net. [173.76.246.42]) by smtp.gmail.com with ESMTPSA id p188sm9361806qkb.43.2019.03.25.08.37.23 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 25 Mar 2019 08:37:24 -0700 (PDT) Date: Mon, 25 Mar 2019 11:37:22 -0400 From: "Michael S. Tsirkin" To: Nitesh Narayan Lal Cc: Alexander Duyck , David Hildenbrand , kvm list , LKML , linux-mm , Paolo Bonzini , lcapitulino@redhat.com, pagupta@redhat.com, wei.w.wang@intel.com, Yang Zhang , Rik van Riel , dodgen@google.com, Konrad Rzeszutek Wilk , dhildenb@redhat.com, Andrea Arcangeli Subject: Re: [RFC][Patch v9 0/6] KVM: Guest Free Page Hinting Message-ID: <20190325113543-mutt-send-email-mst@kernel.org> References: <20190306130955-mutt-send-email-mst@kernel.org> <4bd54f8b-3e9a-3493-40be-668962282431@redhat.com> <6d744ed6-9c1c-b29f-aa32-d38387187b74@redhat.com> <6709bb82-5e99-019d-7de0-3fded385b9ac@redhat.com> <6ab9b763-ac90-b3db-3712-79a20c949d5d@redhat.com> <99b9fa88-17b1-f2a9-7dd4-7a8f6e790d30@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <99b9fa88-17b1-f2a9-7dd4-7a8f6e790d30@redhat.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 25, 2019 at 10:27:46AM -0400, Nitesh Narayan Lal wrote: > I performed some experiments to see if the current implementation of > hinting breaks THP. I used AnonHugePages to track the THP pages > currently in use and memhog as the guest workload. > Setup: > Host Size: 30GB (No swap) > Guest Size: 15GB > THP Size: 2MB > Process: Guest is installed with different kernels to hint different > granularities(MAX_ORDER - 1, MAX_ORDER - 2 and MAX_ORDER - 3). Memhog  > 15G is run multiple times in the same guest to see AnonHugePages usage > in the host. > > Observation: > There is no THP split for order MAX_ORDER - 1 & MAX_ORDER - 2 whereas > for hinting granularity MAX_ORDER - 3 THP does split irrespective of > MADVISE_FREE or MADVISE_DONTNEED. > -- > Regards > Nitesh > This is on x86 right? So THP is 2M and MAX_ORDER is 8M. MAX_ORDER - 3 ==> 1M. Seems to work out. -- MST