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=-5.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 9C764C5DF63 for ; Wed, 6 Nov 2019 06:06:57 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3B4DB20663 for ; Wed, 6 Nov 2019 06:06:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ozlabs.org header.i=@ozlabs.org header.b="HHMCpQKd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B4DB20663 Authentication-Results: mail.kernel.org; dmarc=pass (p=none dis=none) header.from=ozlabs.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 477GJb24MkzF5cQ for ; Wed, 6 Nov 2019 17:06:55 +1100 (AEDT) Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 477G6q5TVTzF3sr for ; Wed, 6 Nov 2019 16:58:27 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=ozlabs.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=ozlabs.org header.i=@ozlabs.org header.b="HHMCpQKd"; dkim-atps=neutral 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 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-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxram@us.ibm.com, cclaudio@linux.ibm.com, kvm-ppc@vger.kernel.org, linux-mm@kvack.org, jglisse@redhat.com, aneesh.kumar@linux.vnet.ibm.com, paulus@au1.ibm.com, sukadev@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, hch@lst.de Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Archived-At: List-Archive: 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