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=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 D941BC433E4 for ; Tue, 14 Jul 2020 19:29:44 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (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 AF281227C3 for ; Tue, 14 Jul 2020 19:29:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="tzoYhF+n" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AF281227C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 97B57116FE12F; Tue, 14 Jul 2020 12:29:44 -0700 (PDT) Received-SPF: None (mailfrom) identity=mailfrom; client-ip=2001:8b0:10b:1231::1; helo=merlin.infradead.org; envelope-from=peterz@infradead.org; receiver= Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 271EF116BF628 for ; Tue, 14 Jul 2020 12:29:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=DxRaLkjpUaoEf0xxT682sMuthlbkUQaqou9xBSEthzs=; b=tzoYhF+ndXteGbrYuyAmg/q9ql lJtaI0FuH3c8J42sQR/E2uYkhCpFeXPc7FOgJmI68T+H7bkQ1q0y60RT2NqowxnJ3StJLPeHeFkX+ OJQuj30D3GKP79EnnrdKlWLBIRpGW8Uk7sk/geT4GGepsLX1EzHvB6k7GgVEqZNBr8+N0VDQGEOvL qCTLoXPiM68Ko3DHDHTOU+jyhW0vavjCzO+PW93pSARAtS+smk4XeVnWr5NFiSvSl/91dIrVZy0Kj 3iEsiKrDzeyxoXFNxo7ATz5CUBvlf0xCdP/0GAON2pptcLhSZ1rsMxpICMN616g+xltCbAX7YAnS8 Yffd4cvw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jvQcO-0002xP-EN; Tue, 14 Jul 2020 19:29:32 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id AA08A9817E0; Tue, 14 Jul 2020 21:29:30 +0200 (CEST) Date: Tue, 14 Jul 2020 21:29:30 +0200 From: Peter Zijlstra To: Ira Weiny Subject: Re: [RFC PATCH 12/15] kmap: Add stray write protection for device pages Message-ID: <20200714192930.GH5523@worktop.programming.kicks-ass.net> References: <20200714070220.3500839-1-ira.weiny@intel.com> <20200714070220.3500839-13-ira.weiny@intel.com> <20200714084451.GQ10769@hirez.programming.kicks-ass.net> <20200714190615.GC3008823@iweiny-DESK2.sc.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200714190615.GC3008823@iweiny-DESK2.sc.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Message-ID-Hash: NETN6VSEOK2WABJQXR32EHZR2PHWC5U5 X-Message-ID-Hash: NETN6VSEOK2WABJQXR32EHZR2PHWC5U5 X-MailFrom: peterz@infradead.org X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski , x86@kernel.org, Dave Hansen , Andrew Morton , Fenghua Yu , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Tue, Jul 14, 2020 at 12:06:16PM -0700, Ira Weiny wrote: > On Tue, Jul 14, 2020 at 10:44:51AM +0200, Peter Zijlstra wrote: > > So, if I followed along correctly, you're proposing to do a WRMSR per > > k{,un}map{_atomic}(), sounds like excellent performance all-round :-( > > Only to pages which have this additional protection, ie not DRAM. > > User mappings of this memory is not affected (would be covered by User PKeys if > desired). User mappings to persistent memory are the primary use case and the > performant path. Because performance to non-volatile memory doesn't matter? I think Dave has a better answer here ... _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org