From nobody Sun Feb 8 07:52:37 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1498677608547903.9016379947091; Wed, 28 Jun 2017 12:20:08 -0700 (PDT) Received: from localhost ([::1]:35331 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dQIVS-0004g0-4W for importer@patchew.org; Wed, 28 Jun 2017 15:20:06 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40896) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dQIEi-0005Rl-K3 for qemu-devel@nongnu.org; Wed, 28 Jun 2017 15:02:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dQIEh-00008W-EN for qemu-devel@nongnu.org; Wed, 28 Jun 2017 15:02:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48090) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dQIEh-00008E-63 for qemu-devel@nongnu.org; Wed, 28 Jun 2017 15:02:47 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1ED3C4E4D0; Wed, 28 Jun 2017 19:02:46 +0000 (UTC) Received: from dgilbert-t530.redhat.com (ovpn-117-210.ams2.redhat.com [10.36.117.210]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8015F5DC1D; Wed, 28 Jun 2017 19:02:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 1ED3C4E4D0 Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=dgilbert@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 1ED3C4E4D0 From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, a.perevalov@samsung.com, marcandre.lureau@redhat.com, maxime.coquelin@redhat.com, mst@redhat.com, quintela@redhat.com, peterx@redhat.com, lvivier@redhat.com, aarcange@redhat.com Date: Wed, 28 Jun 2017 20:00:41 +0100 Message-Id: <20170628190047.26159-24-dgilbert@redhat.com> In-Reply-To: <20170628190047.26159-1-dgilbert@redhat.com> References: <20170628190047.26159-1-dgilbert@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Wed, 28 Jun 2017 19:02:46 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [RFC 23/29] vub+postcopy: madvises X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: "Dr. David Alan Gilbert" Clear the area and turn off THP. Signed-off-by: Dr. David Alan Gilbert --- contrib/libvhost-user/libvhost-user.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/= libvhost-user.c index 0658b6e847..ceddeac74f 100644 --- a/contrib/libvhost-user/libvhost-user.c +++ b/contrib/libvhost-user/libvhost-user.c @@ -451,11 +451,39 @@ vu_set_mem_table_exec(VuDev *dev, VhostUserMsg *vmsg) } =20 if (dev->postcopy_listening) { + int ret; /* We should already have an open ufd need to mark each memory * range as ufd. - * Note: Do we need any madvises? Well it's not been accessed - * yet, still probably need no THP to be safe, discard to be s= afe? */ + + /* Discard any mapping we have here; note I can't use MADV_REM= OVE + * or fallocate to make the hole since I don't want to lose + * data that's already arrived in the shared process. + * TODO: How to do hugepage + */ + ret =3D madvise((void *)dev_region->mmap_addr, + dev_region->size + dev_region->mmap_offset, + MADV_DONTNEED); + if (ret) { + fprintf(stderr, + "%s: Failed to madvise(DONTNEED) region %d: %s\n", + __func__, i, strerror(errno)); + } + /* Turn off transparent hugepages so we dont get lose wakeups + * in neighbouring pages. + * TODO: Turn this backon later. + */ + ret =3D madvise((void *)dev_region->mmap_addr, + dev_region->size + dev_region->mmap_offset, + MADV_NOHUGEPAGE); + if (ret) { + /* Note: This can happen legally on kernels that are confi= gured + * without madvise'able hugepages + */ + fprintf(stderr, + "%s: Failed to madvise(NOHUGEPAGE) region %d: %s\n= ", + __func__, i, strerror(errno)); + } struct uffdio_register reg_struct; /* Note: We might need to go back to using mmap_addr and * len + mmap_offset for * huge pages, but then we do hope not= to --=20 2.13.0