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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 29AC3C5DF62 for ; Wed, 6 Nov 2019 05:58:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B58532075C for ; Wed, 6 Nov 2019 05:58:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ozlabs.org header.i=@ozlabs.org header.b="HHMCpQKd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B58532075C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ozlabs.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4AB636B000E; Wed, 6 Nov 2019 00:58:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 45C5D6B0010; Wed, 6 Nov 2019 00:58:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 370EC6B0266; Wed, 6 Nov 2019 00:58:32 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0099.hostedemail.com [216.40.44.99]) by kanga.kvack.org (Postfix) with ESMTP id 1ED5D6B000E for ; Wed, 6 Nov 2019 00:58:32 -0500 (EST) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id D4B532DFC for ; Wed, 6 Nov 2019 05:58:31 +0000 (UTC) X-FDA: 76124798022.17.low08_849c68ec12246 X-HE-Tag: low08_849c68ec12246 X-Filterd-Recvd-Size: 2233 Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Wed, 6 Nov 2019 05:58:31 +0000 (UTC) Received: by ozlabs.org (Postfix, from userid 1003) id 477G6q2hTsz9sPk; Wed, 6 Nov 2019 16:58:27 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ozlabs.org; s=201707; t=1573019907; bh=46gVeJC3dAyUhPqJ+NlvAv/IlXtVW7QrzM+5gy1u8eM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HHMCpQKdyTCYf5CoNlipflMhC6MOArs1jnJrZWiyfg3s4UQLqUKCAk7jPXWgC7yAe 2ZHWBR0YUuPk4zD9tAwQTZtRmIHc6dtWaGsNGXGnFOQb4wPirBZTrUnUJ10HC1H6o4 nKZ2OIFN6jI+nxz9U3H4gPsliLqud8BLRcuEiuU8p27O16C8ueKYVMK8CrQ0mQpXkI RqlylrOVP7xlVWlS+RF2ye0g8YibvqaO//2XNQ+sFD+Nog0DruyN7vZhjolrqeEk7U UwAK2UJuF/fbivVZliFKXO0XJoZ7dQ3jGSr/3eUllAfeGb27dVreStB8ngrbt4GmI/ rzuV5+OKu7pAw== Date: Wed, 6 Nov 2019 15:33:29 +1100 From: Paul Mackerras To: Bharata B Rao Cc: linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org, linux-mm@kvack.org, paulus@au1.ibm.com, aneesh.kumar@linux.vnet.ibm.com, jglisse@redhat.com, cclaudio@linux.ibm.com, linuxram@us.ibm.com, sukadev@linux.vnet.ibm.com, hch@lst.de Subject: Re: [PATCH v10 1/8] mm: ksm: Export ksm_madvise() Message-ID: <20191106043329.GB12069@oak.ozlabs.ibm.com> References: <20191104041800.24527-1-bharata@linux.ibm.com> <20191104041800.24527-2-bharata@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191104041800.24527-2-bharata@linux.ibm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Nov 04, 2019 at 09:47:53AM +0530, Bharata B Rao wrote: > KVM PPC module needs ksm_madvise() for supporting secure guests. > Guest pages that become secure are represented as device private > pages in the host. Such pages shouldn't participate in KSM merging. If we don't do the ksm_madvise call, then as far as I can tell, it should all still work correctly, but we might have KSM pulling pages in unnecessarily, causing a reduction in performance. Is that right? > Signed-off-by: Bharata B Rao Acked-by: Paul Mackerras