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=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 43B5CC43381 for ; Fri, 15 Feb 2019 12:41:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1090B2075C for ; Fri, 15 Feb 2019 12:41:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387773AbfBOMlH (ORCPT ); Fri, 15 Feb 2019 07:41:07 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42408 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728436AbfBOMlG (ORCPT ); Fri, 15 Feb 2019 07:41:06 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 060C6C7943; Fri, 15 Feb 2019 12:41:04 +0000 (UTC) Received: from [10.40.206.32] (unknown [10.40.206.32]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 76311600C1; Fri, 15 Feb 2019 12:40:58 +0000 (UTC) Subject: Re: [RFC][Patch v8 0/7] KVM: Guest Free Page Hinting To: "Wang, Wei W" , 'David Hildenbrand' , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "pbonzini@redhat.com" , "lcapitulino@redhat.com" , "pagupta@redhat.com" , "yang.zhang.wz@gmail.com" , "riel@surriel.com" , "mst@redhat.com" , "dodgen@google.com" , "konrad.wilk@oracle.com" , "dhildenb@redhat.com" , "aarcange@redhat.com" References: <20190204201854.2328-1-nitesh@redhat.com> <286AC319A985734F985F78AFA26841F73DF6B56A@shsmsx102.ccr.corp.intel.com> <286AC319A985734F985F78AFA26841F73DF6F0E3@shsmsx102.ccr.corp.intel.com> <286AC319A985734F985F78AFA26841F73DF71F38@shsmsx102.ccr.corp.intel.com> From: Nitesh Narayan Lal Openpgp: preference=signencrypt Autocrypt: addr=nitesh@redhat.com; prefer-encrypt=mutual; keydata= mQINBFl4pQoBEADT/nXR2JOfsCjDgYmE2qonSGjkM1g8S6p9UWD+bf7YEAYYYzZsLtbilFTe z4nL4AV6VJmC7dBIlTi3Mj2eymD/2dkKP6UXlliWkq67feVg1KG+4UIp89lFW7v5Y8Muw3Fm uQbFvxyhN8n3tmhRe+ScWsndSBDxYOZgkbCSIfNPdZrHcnOLfA7xMJZeRCjqUpwhIjxQdFA7 n0s0KZ2cHIsemtBM8b2WXSQG9CjqAJHVkDhrBWKThDRF7k80oiJdEQlTEiVhaEDURXq+2XmG jpCnvRQDb28EJSsQlNEAzwzHMeplddfB0vCg9fRk/kOBMDBtGsTvNT9OYUZD+7jaf0gvBvBB lbKmmMMX7uJB+ejY7bnw6ePNrVPErWyfHzR5WYrIFUtgoR3LigKnw5apzc7UIV9G8uiIcZEn C+QJCK43jgnkPcSmwVPztcrkbC84g1K5v2Dxh9amXKLBA1/i+CAY8JWMTepsFohIFMXNLj+B RJoOcR4HGYXZ6CAJa3Glu3mCmYqHTOKwezJTAvmsCLd3W7WxOGF8BbBjVaPjcZfavOvkin0u DaFvhAmrzN6lL0msY17JCZo046z8oAqkyvEflFbC0S1R/POzehKrzQ1RFRD3/YzzlhmIowkM BpTqNBeHEzQAlIhQuyu1ugmQtfsYYq6FPmWMRfFPes/4JUU/PQARAQABtCVOaXRlc2ggTmFy YXlhbiBMYWwgPG5pbGFsQHJlZGhhdC5jb20+iQI9BBMBCAAnBQJZeKUKAhsjBQkJZgGABQsJ CAcCBhUICQoLAgQWAgMBAh4BAheAAAoJEKOGQNwGMqM56lEP/A2KMs/pu0URcVk/kqVwcBhU SnvB8DP3lDWDnmVrAkFEOnPX7GTbactQ41wF/xwjwmEmTzLrMRZpkqz2y9mV0hWHjqoXbOCS 6RwK3ri5e2ThIPoGxFLt6TrMHgCRwm8YuOSJ97o+uohCTN8pmQ86KMUrDNwMqRkeTRW9wWIQ EdDqW44VwelnyPwcmWHBNNb1Kd8j3xKlHtnS45vc6WuoKxYRBTQOwI/5uFpDZtZ1a5kq9Ak/ MOPDDZpd84rqd+IvgMw5z4a5QlkvOTpScD21G3gjmtTEtyfahltyDK/5i8IaQC3YiXJCrqxE r7/4JMZeOYiKpE9iZMtS90t4wBgbVTqAGH1nE/ifZVAUcCtycD0f3egX9CHe45Ad4fsF3edQ ESa5tZAogiA4Hc/yQpnnf43a3aQ67XPOJXxS0Qptzu4vfF9h7kTKYWSrVesOU3QKYbjEAf95 NewF9FhAlYqYrwIwnuAZ8TdXVDYt7Z3z506//sf6zoRwYIDA8RDqFGRuPMXUsoUnf/KKPrtR ceLcSUP/JCNiYbf1/QtW8S6Ca/4qJFXQHp0knqJPGmwuFHsarSdpvZQ9qpxD3FnuPyo64S2N Dfq8TAeifNp2pAmPY2PAHQ3nOmKgMG8Gn5QiORvMUGzSz8Lo31LW58NdBKbh6bci5+t/HE0H pnyVf5xhNC/FuQINBFl4pQoBEACr+MgxWHUP76oNNYjRiNDhaIVtnPRqxiZ9v4H5FPxJy9UD Bqr54rifr1E+K+yYNPt/Po43vVL2cAyfyI/LVLlhiY4yH6T1n+Di/hSkkviCaf13gczuvgz4 KVYLwojU8+naJUsiCJw01MjO3pg9GQ+47HgsnRjCdNmmHiUQqksMIfd8k3reO9SUNlEmDDNB XuSzkHjE5y/R/6p8uXaVpiKPfHoULjNRWaFc3d2JGmxJpBdpYnajoz61m7XJlgwl/B5Ql/6B dHGaX3VHxOZsfRfugwYF9CkrPbyO5PK7yJ5vaiWre7aQ9bmCtXAomvF1q3/qRwZp77k6i9R3 tWfXjZDOQokw0u6d6DYJ0Vkfcwheg2i/Mf/epQl7Pf846G3PgSnyVK6cRwerBl5a68w7xqVU 4KgAh0DePjtDcbcXsKRT9D63cfyfrNE+ea4i0SVik6+N4nAj1HbzWHTk2KIxTsJXypibOKFX 2VykltxutR1sUfZBYMkfU4PogE7NjVEU7KtuCOSAkYzIWrZNEQrxYkxHLJsWruhSYNRsqVBy KvY6JAsq/i5yhVd5JKKU8wIOgSwC9P6mXYRgwPyfg15GZpnw+Fpey4bCDkT5fMOaCcS+vSU1 UaFmC4Ogzpe2BW2DOaPU5Ik99zUFNn6cRmOOXArrryjFlLT5oSOe4IposgWzdwARAQABiQIl BBgBCAAPBQJZeKUKAhsMBQkJZgGAAAoJEKOGQNwGMqM5ELoP/jj9d9gF1Al4+9bngUlYohYu 0sxyZo9IZ7Yb7cHuJzOMqfgoP4tydP4QCuyd9Q2OHHL5AL4VFNb8SvqAxxYSPuDJTI3JZwI7 d8JTPKwpulMSUaJE8ZH9n8A/+sdC3CAD4QafVBcCcbFe1jifHmQRdDrvHV9Es14QVAOTZhnJ vweENyHEIxkpLsyUUDuVypIo6y/Cws+EBCWt27BJi9GH/EOTB0wb+2ghCs/i3h8a+bi+bS7L FCCm/AxIqxRurh2UySn0P/2+2eZvneJ1/uTgfxnjeSlwQJ1BWzMAdAHQO1/lnbyZgEZEtUZJ x9d9ASekTtJjBMKJXAw7GbB2dAA/QmbA+Q+Xuamzm/1imigz6L6sOt2n/X/SSc33w8RJUyor SvAIoG/zU2Y76pKTgbpQqMDmkmNYFMLcAukpvC4ki3Sf086TdMgkjqtnpTkEElMSFJC8npXv 3QnGGOIfFug/qs8z03DLPBz9VYS26jiiN7QIJVpeeEdN/LKnaz5LO+h5kNAyj44qdF2T2AiF HxnZnxO5JNP5uISQH3FjxxGxJkdJ8jKzZV7aT37sC+Rp0o3KNc+GXTR+GSVq87Xfuhx0LRST NK9ZhT0+qkiN7npFLtNtbzwqaqceq3XhafmCiw8xrtzCnlB/C4SiBr/93Ip4kihXJ0EuHSLn VujM7c/b4pps Organization: Red Hat Inc, Message-ID: <8c65b48c-6e28-f28b-c8f0-5a2c78cf52a5@redhat.com> Date: Fri, 15 Feb 2019 07:40:55 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <286AC319A985734F985F78AFA26841F73DF71F38@shsmsx102.ccr.corp.intel.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="qusNYtOEDPs1948kwFoAVU2s4iAWJUCqI" X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 15 Feb 2019 12:41:06 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --qusNYtOEDPs1948kwFoAVU2s4iAWJUCqI Content-Type: multipart/mixed; boundary="19xowJ6YcPLQjp6lxipmMsFPTwWfNFUy4"; protected-headers="v1" From: Nitesh Narayan Lal To: "Wang, Wei W" , 'David Hildenbrand' , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "pbonzini@redhat.com" , "lcapitulino@redhat.com" , "pagupta@redhat.com" , "yang.zhang.wz@gmail.com" , "riel@surriel.com" , "mst@redhat.com" , "dodgen@google.com" , "konrad.wilk@oracle.com" , "dhildenb@redhat.com" , "aarcange@redhat.com" Message-ID: <8c65b48c-6e28-f28b-c8f0-5a2c78cf52a5@redhat.com> Subject: Re: [RFC][Patch v8 0/7] KVM: Guest Free Page Hinting References: <20190204201854.2328-1-nitesh@redhat.com> <286AC319A985734F985F78AFA26841F73DF6B56A@shsmsx102.ccr.corp.intel.com> <286AC319A985734F985F78AFA26841F73DF6F0E3@shsmsx102.ccr.corp.intel.com> <286AC319A985734F985F78AFA26841F73DF71F38@shsmsx102.ccr.corp.intel.com> In-Reply-To: <286AC319A985734F985F78AFA26841F73DF71F38@shsmsx102.ccr.corp.intel.com> --19xowJ6YcPLQjp6lxipmMsFPTwWfNFUy4 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Content-Language: en-US On 2/15/19 4:05 AM, Wang, Wei W wrote: > On Thursday, February 14, 2019 5:43 PM, David Hildenbrand wrote: >> Yes indeed, that is the important bit. They must not be put pack to th= e >> buddy before they have been processed by the hypervisor. But as the pa= ges >> are not in the buddy, no one allocating a page will stumble over such = a page >> and try to allocate it. Threads trying to allocate memory will simply = pick >> another buddy page instead of "busy waiting" for that page to be finis= hed >> reporting. > What if a guest thread try to allocate some pages but the buddy cannot = satisfy > because all the pages are isolated? Would it be the same case that the = guest thread > gets blocked by waiting all the isolated pages to get madvised by the h= ost and > returned to the guest buddy, or even worse, some guest threads get kill= ed due to oom? If you are referring to a situation when guest is under memory pressure then isolation request will fail and memory will not be reported/isolated. However, there can always be a corner case and we can definitely take that into consideration later. > > Best, > Wei --=20 Regards Nitesh --19xowJ6YcPLQjp6lxipmMsFPTwWfNFUy4-- --qusNYtOEDPs1948kwFoAVU2s4iAWJUCqI Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEkXcoRVGaqvbHPuAGo4ZA3AYyozkFAlxms1cACgkQo4ZA3AYy ozkrkQ/9FFmzLrvp+OyyZFaaOTjfTJ/MaxhVGuBp1mPHgBqn3MT4cUBoeSPSW+hf 3XxgJUBqQF5hIeQpkHUEKFH4felhdZaytFhaicQEFmeB9MgQDJ1+fkN9qHZjheK7 GFDOEUvE70ADLDe65a+EOkXLTDS8urzcqghrToFxHTard9GeFG5o47N9O/9Zz3Ay 8mZ5AXGHmU6jNZX5cIdNn1ydzibcsVdN08gU4y6bumXhUqpNw6lwrfTKXl1BfFb5 8BD9SvtaG0NRcWz7o6dVVkSXHxAZu6ah2NT2wLJUsHWWrCE7LGaaO790Y52bSGdX dqK17G2e+F9nZZnDwXf8c7+z3QmG3TmFADp8MgLfnRWOyhqha6qcOFNEwfmkZOrF H8qURMrVkxz5VQMn2r1i3CoC2NaLGaJpfuIhEmz4P+KdXL2xaIn4RF9uTxG47cG5 f5nl59dFMw/SdayicriqXOfNPMCUQDBGYKJ/We2zwJ8iw8OyCrsO0wb7KP0sK3fx YaAHMj2tk+k5PNqfk3EkoX1Q+OGNw7YxcSkXfD1bAbA9sRkEoeo2ZQkGEI/6E59W PSMOASzP2He+00WZoToVE2jHk5pXTCpebLr7F6NQ/4kpY3HNDvkKGoyU4ECi/zI2 APz8MchKAqKFTY6OuKGNeIyVFiV1UMUpxEAqrzbItqjUkRoglT4= =ESEC -----END PGP SIGNATURE----- --qusNYtOEDPs1948kwFoAVU2s4iAWJUCqI--