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=-0.8 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 41EE2C1B0F2 for ; Wed, 20 Jun 2018 09:11:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 071A620652 for ; Wed, 20 Jun 2018 09:11:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 071A620652 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.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 S1754845AbeFTJLy convert rfc822-to-8bit (ORCPT ); Wed, 20 Jun 2018 05:11:54 -0400 Received: from mga09.intel.com ([134.134.136.24]:1519 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752308AbeFTJLt (ORCPT ); Wed, 20 Jun 2018 05:11:49 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Jun 2018 02:11:48 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,246,1526367600"; d="scan'208";a="60738562" Received: from fmsmsx107.amr.corp.intel.com ([10.18.124.205]) by orsmga003.jf.intel.com with ESMTP; 20 Jun 2018 02:11:47 -0700 Received: from fmsmsx154.amr.corp.intel.com (10.18.116.70) by fmsmsx107.amr.corp.intel.com (10.18.124.205) with Microsoft SMTP Server (TLS) id 14.3.319.2; Wed, 20 Jun 2018 02:11:47 -0700 Received: from shsmsx104.ccr.corp.intel.com (10.239.4.70) by FMSMSX154.amr.corp.intel.com (10.18.116.70) with Microsoft SMTP Server (TLS) id 14.3.319.2; Wed, 20 Jun 2018 02:11:47 -0700 Received: from shsmsx102.ccr.corp.intel.com ([169.254.2.223]) by SHSMSX104.ccr.corp.intel.com ([169.254.5.87]) with mapi id 14.03.0319.002; Wed, 20 Jun 2018 17:11:40 +0800 From: "Wang, Wei W" To: "Michael S. Tsirkin" CC: "virtio-dev@lists.oasis-open.org" , "linux-kernel@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "kvm@vger.kernel.org" , "linux-mm@kvack.org" , "mhocko@kernel.org" , "akpm@linux-foundation.org" , "torvalds@linux-foundation.org" , "pbonzini@redhat.com" , "liliang.opensource@gmail.com" , "yang.zhang.wz@gmail.com" , "quan.xu0@gmail.com" , "nilal@redhat.com" , "riel@redhat.com" , "peterx@redhat.com" Subject: RE: [virtio-dev] Re: [PATCH v33 2/4] virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT Thread-Topic: [virtio-dev] Re: [PATCH v33 2/4] virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT Thread-Index: AQHUBGb1uIuE7GdLXUGMzLE4+zixk6RgrO+AgACbr0D//5LxAIAAh+EwgANlzICAAQ0KgIAAj48AgAEfQ4D//6O1gIABpEBg Date: Wed, 20 Jun 2018 09:11:39 +0000 Message-ID: <286AC319A985734F985F78AFA26841F7396AE2EC@shsmsx102.ccr.corp.intel.com> References: <1529037793-35521-1-git-send-email-wei.w.wang@intel.com> <1529037793-35521-3-git-send-email-wei.w.wang@intel.com> <20180615144000-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F7396A3D04@shsmsx102.ccr.corp.intel.com> <20180615171635-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F7396A5CB0@shsmsx102.ccr.corp.intel.com> <20180618051637-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F7396AA10C@shsmsx102.ccr.corp.intel.com> <20180619055449-mutt-send-email-mst@kernel.org> <5B28F371.9020308@intel.com> <20180619173256-mutt-send-email-mst@kernel.org> In-Reply-To: <20180619173256-mutt-send-email-mst@kernel.org> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiMGYwOWMxNWUtNzNiYi00YTk3LTgzOWItNThkYzY3NjZlMmIwIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjEwLjE4MDQuNDkiLCJUcnVzdGVkTGFiZWxIYXNoIjoiZGFPNFhhY2tvWDNIV3FyK1hnVVJsb3E3TDdEVXFsSE1qZjNiMnIxaWhZcnJtQ2lYbnhmczZvRWVFZmNGSkJhdSJ9 x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.0.200.100 dlp-reaction: no-action x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday, June 19, 2018 10:43 PM, Michael S. Tsirk wrote: > On Tue, Jun 19, 2018 at 08:13:37PM +0800, Wei Wang wrote: > > On 06/19/2018 11:05 AM, Michael S. Tsirkin wrote: > > > On Tue, Jun 19, 2018 at 01:06:48AM +0000, Wang, Wei W wrote: > > > > On Monday, June 18, 2018 10:29 AM, Michael S. Tsirkin wrote: > > > > > On Sat, Jun 16, 2018 at 01:09:44AM +0000, Wang, Wei W wrote: > > > > > > Not necessarily, I think. We have min(4m_page_blocks / 512, > > > > > > 1024) above, > > > > > so the maximum memory that can be reported is 2TB. For larger > guests, e.g. > > > > > 4TB, the optimization can still offer 2TB free memory (better > > > > > than no optimization). > > > > > > > > > > Maybe it's better, maybe it isn't. It certainly muddies the waters even > more. > > > > > I'd rather we had a better plan. From that POV I like what > > > > > Matthew Wilcox suggested for this which is to steal the necessary # of > entries off the list. > > > > Actually what Matthew suggested doesn't make a difference here. > > > > That method always steal the first free page blocks, and sure can > > > > be changed to take more. But all these can be achieved via kmalloc > > > I'd do get_user_pages really. You don't want pages split, etc. > > Oops sorry. I meant get_free_pages . Yes, we can use __get_free_pages, and the max allocation is MAX_ORDER - 1, which can report up to 2TB free memory. "getting two pages isn't harder", do you mean passing two arrays (two allocations by get_free_pages(,MAX_ORDER -1)) to the mm API? Please see if the following logic aligns to what you think: uint32_t i, max_hints, hints_per_page, hints_per_array, total_arrays; unsigned long *arrays; /* * Each array size is MAX_ORDER_NR_PAGES. If one array is not enough to * store all the hints, we need to allocate multiple arrays. * max_hints: the max number of 4MB free page blocks * hints_per_page: the number of hints each page can store * hints_per_array: the number of hints an array can store * total_arrays: the number of arrays we need */ max_hints = totalram_pages / MAX_ORDER_NR_PAGES; hints_per_page = PAGE_SIZE / sizeof(__le64); hints_per_array = hints_per_page * MAX_ORDER_NR_PAGES; total_arrays = max_hints / hints_per_array + !!(max_hints % hints_per_array); arrays = kmalloc(total_arrays * sizeof(unsigned long), GFP_KERNEL); for (i = 0; i < total_arrays; i++) { arrays[i] = __get_free_pages(__GFP_ATOMIC | __GFP_NOMEMALLOC, MAX_ORDER - 1); if (!arrays[i]) goto out; } - the mm API needs to be changed to support storing hints to multiple separated arrays offered by the caller. Best, Wei From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Wang, Wei W" Subject: RE: [virtio-dev] Re: [PATCH v33 2/4] virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT Date: Wed, 20 Jun 2018 09:11:39 +0000 Message-ID: <286AC319A985734F985F78AFA26841F7396AE2EC@shsmsx102.ccr.corp.intel.com> References: <1529037793-35521-1-git-send-email-wei.w.wang@intel.com> <1529037793-35521-3-git-send-email-wei.w.wang@intel.com> <20180615144000-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F7396A3D04@shsmsx102.ccr.corp.intel.com> <20180615171635-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F7396A5CB0@shsmsx102.ccr.corp.intel.com> <20180618051637-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F7396AA10C@shsmsx102.ccr.corp.intel.com> <20180619055449-mutt-send-email-mst@kernel.org> <5B28F371.9020308@intel.com> <20180619173256-mutt-send-email-mst@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: "yang.zhang.wz@gmail.com" , "virtio-dev@lists.oasis-open.org" , "riel@redhat.com" , "quan.xu0@gmail.com" , "kvm@vger.kernel.org" , "nilal@redhat.com" , "liliang.opensource@gmail.com" , "linux-kernel@vger.kernel.org" , "mhocko@kernel.org" , "linux-mm@kvack.org" , "pbonzini@redhat.com" , "akpm@linux-foundation.org" , "virtualization@lists.linux-foundation.org" , "torvalds@linux-foundation.org" To: "Michael S. Tsirkin" Return-path: In-Reply-To: <20180619173256-mutt-send-email-mst@kernel.org> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: kvm.vger.kernel.org On Tuesday, June 19, 2018 10:43 PM, Michael S. Tsirk wrote: > On Tue, Jun 19, 2018 at 08:13:37PM +0800, Wei Wang wrote: > > On 06/19/2018 11:05 AM, Michael S. Tsirkin wrote: > > > On Tue, Jun 19, 2018 at 01:06:48AM +0000, Wang, Wei W wrote: > > > > On Monday, June 18, 2018 10:29 AM, Michael S. Tsirkin wrote: > > > > > On Sat, Jun 16, 2018 at 01:09:44AM +0000, Wang, Wei W wrote: > > > > > > Not necessarily, I think. We have min(4m_page_blocks / 512, > > > > > > 1024) above, > > > > > so the maximum memory that can be reported is 2TB. For larger > guests, e.g. > > > > > 4TB, the optimization can still offer 2TB free memory (better > > > > > than no optimization). > > > > > > > > > > Maybe it's better, maybe it isn't. It certainly muddies the waters even > more. > > > > > I'd rather we had a better plan. From that POV I like what > > > > > Matthew Wilcox suggested for this which is to steal the necessary # of > entries off the list. > > > > Actually what Matthew suggested doesn't make a difference here. > > > > That method always steal the first free page blocks, and sure can > > > > be changed to take more. But all these can be achieved via kmalloc > > > I'd do get_user_pages really. You don't want pages split, etc. > > Oops sorry. I meant get_free_pages . Yes, we can use __get_free_pages, and the max allocation is MAX_ORDER - 1, which can report up to 2TB free memory. "getting two pages isn't harder", do you mean passing two arrays (two allocations by get_free_pages(,MAX_ORDER -1)) to the mm API? Please see if the following logic aligns to what you think: uint32_t i, max_hints, hints_per_page, hints_per_array, total_arrays; unsigned long *arrays; /* * Each array size is MAX_ORDER_NR_PAGES. If one array is not enough to * store all the hints, we need to allocate multiple arrays. * max_hints: the max number of 4MB free page blocks * hints_per_page: the number of hints each page can store * hints_per_array: the number of hints an array can store * total_arrays: the number of arrays we need */ max_hints = totalram_pages / MAX_ORDER_NR_PAGES; hints_per_page = PAGE_SIZE / sizeof(__le64); hints_per_array = hints_per_page * MAX_ORDER_NR_PAGES; total_arrays = max_hints / hints_per_array + !!(max_hints % hints_per_array); arrays = kmalloc(total_arrays * sizeof(unsigned long), GFP_KERNEL); for (i = 0; i < total_arrays; i++) { arrays[i] = __get_free_pages(__GFP_ATOMIC | __GFP_NOMEMALLOC, MAX_ORDER - 1); if (!arrays[i]) goto out; } - the mm API needs to be changed to support storing hints to multiple separated arrays offered by the caller. Best, Wei From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f70.google.com (mail-pg0-f70.google.com [74.125.83.70]) by kanga.kvack.org (Postfix) with ESMTP id 5D05F6B0003 for ; Wed, 20 Jun 2018 05:11:50 -0400 (EDT) Received: by mail-pg0-f70.google.com with SMTP id j10-v6so1067201pgv.6 for ; Wed, 20 Jun 2018 02:11:50 -0700 (PDT) Received: from mga17.intel.com (mga17.intel.com. [192.55.52.151]) by mx.google.com with ESMTPS id t4-v6si1669267pgf.79.2018.06.20.02.11.48 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Jun 2018 02:11:49 -0700 (PDT) From: "Wang, Wei W" Subject: RE: [virtio-dev] Re: [PATCH v33 2/4] virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT Date: Wed, 20 Jun 2018 09:11:39 +0000 Message-ID: <286AC319A985734F985F78AFA26841F7396AE2EC@shsmsx102.ccr.corp.intel.com> References: <1529037793-35521-1-git-send-email-wei.w.wang@intel.com> <1529037793-35521-3-git-send-email-wei.w.wang@intel.com> <20180615144000-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F7396A3D04@shsmsx102.ccr.corp.intel.com> <20180615171635-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F7396A5CB0@shsmsx102.ccr.corp.intel.com> <20180618051637-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F7396AA10C@shsmsx102.ccr.corp.intel.com> <20180619055449-mutt-send-email-mst@kernel.org> <5B28F371.9020308@intel.com> <20180619173256-mutt-send-email-mst@kernel.org> In-Reply-To: <20180619173256-mutt-send-email-mst@kernel.org> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: "Michael S. Tsirkin" Cc: "virtio-dev@lists.oasis-open.org" , "linux-kernel@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "kvm@vger.kernel.org" , "linux-mm@kvack.org" , "mhocko@kernel.org" , "akpm@linux-foundation.org" , "torvalds@linux-foundation.org" , "pbonzini@redhat.com" , "liliang.opensource@gmail.com" , "yang.zhang.wz@gmail.com" , "quan.xu0@gmail.com" , "nilal@redhat.com" , "riel@redhat.com" , "peterx@redhat.com" On Tuesday, June 19, 2018 10:43 PM, Michael S. Tsirk wrote: > On Tue, Jun 19, 2018 at 08:13:37PM +0800, Wei Wang wrote: > > On 06/19/2018 11:05 AM, Michael S. Tsirkin wrote: > > > On Tue, Jun 19, 2018 at 01:06:48AM +0000, Wang, Wei W wrote: > > > > On Monday, June 18, 2018 10:29 AM, Michael S. Tsirkin wrote: > > > > > On Sat, Jun 16, 2018 at 01:09:44AM +0000, Wang, Wei W wrote: > > > > > > Not necessarily, I think. We have min(4m_page_blocks / 512, > > > > > > 1024) above, > > > > > so the maximum memory that can be reported is 2TB. For larger > guests, e.g. > > > > > 4TB, the optimization can still offer 2TB free memory (better > > > > > than no optimization). > > > > > > > > > > Maybe it's better, maybe it isn't. It certainly muddies the water= s even > more. > > > > > I'd rather we had a better plan. From that POV I like what > > > > > Matthew Wilcox suggested for this which is to steal the necessary= # of > entries off the list. > > > > Actually what Matthew suggested doesn't make a difference here. > > > > That method always steal the first free page blocks, and sure can > > > > be changed to take more. But all these can be achieved via kmalloc > > > I'd do get_user_pages really. You don't want pages split, etc. >=20 > Oops sorry. I meant get_free_pages . Yes, we can use __get_free_pages, and the max allocation is MAX_ORDER - 1, = which can report up to 2TB free memory.=20 "getting two pages isn't harder", do you mean passing two arrays (two alloc= ations by get_free_pages(,MAX_ORDER -1)) to the mm API? Please see if the following logic aligns to what you think: uint32_t i, max_hints, hints_per_page, hints_per_array, total_array= s; unsigned long *arrays; =20 /* * Each array size is MAX_ORDER_NR_PAGES. If one array is not enoug= h to * store all the hints, we need to allocate multiple arrays. * max_hints: the max number of 4MB free page blocks * hints_per_page: the number of hints each page can store * hints_per_array: the number of hints an array can store * total_arrays: the number of arrays we need */ max_hints =3D totalram_pages / MAX_ORDER_NR_PAGES; hints_per_page =3D PAGE_SIZE / sizeof(__le64); hints_per_array =3D hints_per_page * MAX_ORDER_NR_PAGES; total_arrays =3D max_hints / hints_per_array + !!(max_hints % hints_per_array); arrays =3D kmalloc(total_arrays * sizeof(unsigned long), GFP_KERNEL= ); for (i =3D 0; i < total_arrays; i++) { arrays[i] =3D __get_free_pages(__GFP_ATOMIC | __GFP_NOMEMAL= LOC, MAX_ORDER - 1); if (!arrays[i]) goto out; } - the mm API needs to be changed to support storing hints to multiple separ= ated arrays offered by the caller. Best, Wei From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-4452-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [66.179.20.138]) by lists.oasis-open.org (Postfix) with ESMTP id 0CBE958191A2 for ; Wed, 20 Jun 2018 02:11:59 -0700 (PDT) From: "Wang, Wei W" Date: Wed, 20 Jun 2018 09:11:39 +0000 Message-ID: <286AC319A985734F985F78AFA26841F7396AE2EC@shsmsx102.ccr.corp.intel.com> References: <1529037793-35521-1-git-send-email-wei.w.wang@intel.com> <1529037793-35521-3-git-send-email-wei.w.wang@intel.com> <20180615144000-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F7396A3D04@shsmsx102.ccr.corp.intel.com> <20180615171635-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F7396A5CB0@shsmsx102.ccr.corp.intel.com> <20180618051637-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F7396AA10C@shsmsx102.ccr.corp.intel.com> <20180619055449-mutt-send-email-mst@kernel.org> <5B28F371.9020308@intel.com> <20180619173256-mutt-send-email-mst@kernel.org> In-Reply-To: <20180619173256-mutt-send-email-mst@kernel.org> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: RE: [virtio-dev] Re: [PATCH v33 2/4] virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT To: "Michael S. Tsirkin" Cc: "virtio-dev@lists.oasis-open.org" , "linux-kernel@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "kvm@vger.kernel.org" , "linux-mm@kvack.org" , "mhocko@kernel.org" , "akpm@linux-foundation.org" , "torvalds@linux-foundation.org" , "pbonzini@redhat.com" , "liliang.opensource@gmail.com" , "yang.zhang.wz@gmail.com" , "quan.xu0@gmail.com" , "nilal@redhat.com" , "riel@redhat.com" , "peterx@redhat.com" List-ID: On Tuesday, June 19, 2018 10:43 PM, Michael S. Tsirk wrote: > On Tue, Jun 19, 2018 at 08:13:37PM +0800, Wei Wang wrote: > > On 06/19/2018 11:05 AM, Michael S. Tsirkin wrote: > > > On Tue, Jun 19, 2018 at 01:06:48AM +0000, Wang, Wei W wrote: > > > > On Monday, June 18, 2018 10:29 AM, Michael S. Tsirkin wrote: > > > > > On Sat, Jun 16, 2018 at 01:09:44AM +0000, Wang, Wei W wrote: > > > > > > Not necessarily, I think. We have min(4m_page_blocks / 512, > > > > > > 1024) above, > > > > > so the maximum memory that can be reported is 2TB. For larger > guests, e.g. > > > > > 4TB, the optimization can still offer 2TB free memory (better > > > > > than no optimization). > > > > > > > > > > Maybe it's better, maybe it isn't. It certainly muddies the water= s even > more. > > > > > I'd rather we had a better plan. From that POV I like what > > > > > Matthew Wilcox suggested for this which is to steal the necessary= # of > entries off the list. > > > > Actually what Matthew suggested doesn't make a difference here. > > > > That method always steal the first free page blocks, and sure can > > > > be changed to take more. But all these can be achieved via kmalloc > > > I'd do get_user_pages really. You don't want pages split, etc. >=20 > Oops sorry. I meant get_free_pages . Yes, we can use __get_free_pages, and the max allocation is MAX_ORDER - 1, = which can report up to 2TB free memory.=20 "getting two pages isn't harder", do you mean passing two arrays (two alloc= ations by get_free_pages(,MAX_ORDER -1)) to the mm API? Please see if the following logic aligns to what you think: uint32_t i, max_hints, hints_per_page, hints_per_array, total_array= s; unsigned long *arrays; =20 /* * Each array size is MAX_ORDER_NR_PAGES. If one array is not enoug= h to * store all the hints, we need to allocate multiple arrays. * max_hints: the max number of 4MB free page blocks * hints_per_page: the number of hints each page can store * hints_per_array: the number of hints an array can store * total_arrays: the number of arrays we need */ max_hints =3D totalram_pages / MAX_ORDER_NR_PAGES; hints_per_page =3D PAGE_SIZE / sizeof(__le64); hints_per_array =3D hints_per_page * MAX_ORDER_NR_PAGES; total_arrays =3D max_hints / hints_per_array + !!(max_hints % hints_per_array); arrays =3D kmalloc(total_arrays * sizeof(unsigned long), GFP_KERNEL= ); for (i =3D 0; i < total_arrays; i++) { arrays[i] =3D __get_free_pages(__GFP_ATOMIC | __GFP_NOMEMAL= LOC, MAX_ORDER - 1); if (!arrays[i]) goto out; } - the mm API needs to be changed to support storing hints to multiple separ= ated arrays offered by the caller. Best, Wei --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org