From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759354AbcG1DsW (ORCPT ); Wed, 27 Jul 2016 23:48:22 -0400 Received: from mga02.intel.com ([134.134.136.20]:9687 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759052AbcG1DsU convert rfc822-to-8bit (ORCPT ); Wed, 27 Jul 2016 23:48:20 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,433,1464678000"; d="scan'208";a="854944641" From: "Li, Liang Z" To: "Michael S. Tsirkin" CC: "linux-kernel@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "linux-mm@kvack.org" , "virtio-dev@lists.oasis-open.org" , "kvm@vger.kernel.org" , "qemu-devel@nongnu.org" , "dgilbert@redhat.com" , "quintela@redhat.com" , Andrew Morton , "Vlastimil Babka" , Mel Gorman , "Paolo Bonzini" , Cornelia Huck , Amit Shah Subject: RE: [PATCH v2 repost 4/7] virtio-balloon: speed up inflate/deflate process Thread-Topic: [PATCH v2 repost 4/7] virtio-balloon: speed up inflate/deflate process Thread-Index: AQHR56aT5WMR4KLffEuOEzyB2S9p86AsUQ2AgADkMBA= Date: Thu, 28 Jul 2016 03:48:16 +0000 Message-ID: References: <1469582616-5729-1-git-send-email-liang.z.li@intel.com> <1469582616-5729-5-git-send-email-liang.z.li@intel.com> <20160728010616-mutt-send-email-mst@kernel.org> In-Reply-To: <20160728010616-mutt-send-email-mst@kernel.org> Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiYTdjOGQ3YTEtMDllOS00MDcyLWEyOGYtYzM1NzJjMDU3OWE5IiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE1LjkuNi42IiwiVHJ1c3RlZExhYmVsSGFzaCI6IkQ0d3JoUzFYK3NwOUE2WHhcL2lyMUJCSlQxZ1pSbzBKaUZLSDhGNkNrN0ZvPSJ9 x-ctpclassification: CTP_IC 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > +/* > > + * VIRTIO_BALLOON_PFNS_LIMIT is used to limit the size of page bitmap > > + * to prevent a very large page bitmap, there are two reasons for this: > > + * 1) to save memory. > > + * 2) allocate a large bitmap may fail. > > + * > > + * The actual limit of pfn is determined by: > > + * pfn_limit = min(max_pfn, VIRTIO_BALLOON_PFNS_LIMIT); > > + * > > + * If system has more pages than VIRTIO_BALLOON_PFNS_LIMIT, we will > > +scan > > + * the page list and send the PFNs with several times. To reduce the > > + * overhead of scanning the page list. VIRTIO_BALLOON_PFNS_LIMIT > > +should > > + * be set with a value which can cover most cases. > > + */ > > +#define VIRTIO_BALLOON_PFNS_LIMIT ((32 * (1ULL << 30)) >> > PAGE_SHIFT) > > +/* 32GB */ > > + > > static int oom_pages = OOM_VBALLOON_DEFAULT_PAGES; > > module_param(oom_pages, int, S_IRUSR | S_IWUSR); > > MODULE_PARM_DESC(oom_pages, "pages to free on OOM"); > > > > +extern unsigned long get_max_pfn(void); > > + > > Please just include the correct header. No need for this hackery. > Will change. Thanks! Liang