From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-2783972-1527008240-2-11270265129616761002 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-charsets: plain='us-ascii' X-Resolved-to: linux@kroah.com X-Delivered-to: linux@kroah.com X-Mail-from: linux-fsdevel-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1527008240; b=jTDu3zvvtPNLiDgd/REZrbXJAW1wj4A91ZtYRS2sqQmQqij/ij lLHDR4dpjrOIQjM1VTP6OlcZsUJhFPpJbvkc2ch8+13EKWlXoUkxMg6HAdHomV2H id3U59VwfmGvXlE3XJjYdICFaB4s9ctGkXerJs6vBn1lAfBD47TQSWzN3zZ4dAvX kR57AYya0cYU4eu7uQQuBwml1ImP6PbwwyDUfLTCUdkGA9yzOMbTZ2j8lBlD5Iih srJoL1wSGShYUyesnB4ij8+lPiCL1VxjwtkQl4ONLWiERr6aVxiUpqsv6mxcPFAb qtLRIuGAE+261UU7odIBclAAUGEqka1S0UIg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to:sender :list-id; s=fm2; t=1527008240; bh=+8pUlMKwPRDhzM1Ba77drv/5rnd0qn a6ms5DL8LG9cw=; b=WXkD7TIfAvL9t3aETIToROGKUxmu2ovdwE4qqzl+4oyupS c2cGPlAMh3kdmbjtmbQp2RPNDg+1C6/yRV7ats8x9Ynl2biU+EKU9CCmjpDhKw3D ug0KbP9DDwtg7OmZ/8o/EoSCMbg5hTP3vIp8aXD78IuiziHcomU9sSRbU5Cygb2n tPzVw8XFzKrw2qz/xfqUrjtoO9a35GwIH1kFcuvOwllyEz5ZuvJbcNIMeuRnogVR UitI3/KzaEkUeFYY7+QOyYk0oKudmr4r8BIfJKKv5lAqWOjj6ABC4/IELGDxla+2 P4b9AUUCQleXSpD/9ccc1OueLri+jmY+kQdPW3dQ== ARC-Authentication-Results: i=1; mx5.messagingengine.com; arc=none (no signatures found); dkim=fail (message has been altered, 2048-bit rsa key sha256) header.d=infradead.org header.i=@infradead.org header.b=kUX9LB+D x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=bombadil.20170209; dmarc=none (p=none,has-list-id=yes,d=none) header.from=infradead.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-fsdevel-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=infradead.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx5.messagingengine.com; arc=none (no signatures found); dkim=fail (message has been altered, 2048-bit rsa key sha256) header.d=infradead.org header.i=@infradead.org header.b=kUX9LB+D x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=bombadil.20170209; dmarc=none (p=none,has-list-id=yes,d=none) header.from=infradead.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-fsdevel-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=infradead.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfKT42M/JLucpF8fhPJm3QGU8SHLsupglhvSREZOR0RGML0qCAvvrJO7QPxsCwnVvI6aw/tOehQ1eCvxLxiiS64F07n43v66HjdpbGpXiLe7RTwQHpYK3 61tg1M+9VgwOCb5KLXLfnnpvEkFj29n53sdoTbjjs3obGs6gdGClIaqlojAVGYiv7/5iBPo6NoSyZjNia0rPwFbL0zSAtPegjgfl1oOll4I5zwWwnklcVTyi X-CM-Analysis: v=2.3 cv=NPP7BXyg c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=kj9zAlcOel0A:10 a=VUJBJC2UJ8kA:10 a=cXFKZvxVt2skxZyhM1wA:9 a=CjuIK1q_8ugA:10 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751575AbeEVQ5Q (ORCPT ); Tue, 22 May 2018 12:57:16 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:47902 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751326AbeEVQ4v (ORCPT ); Tue, 22 May 2018 12:56:51 -0400 Date: Tue, 22 May 2018 18:56:41 +0200 From: Peter Zijlstra To: Christopher Lameter Cc: Dave Hansen , Boaz Harrosh , Jeff Moyer , Matthew Wilcox , Andrew Morton , "Kirill A. Shutemov" , linux-kernel , linux-fsdevel , "linux-mm@kvack.org" , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Rik van Riel , Jan Kara , Matthew Wilcox , Amit Golander Subject: Re: [PATCH] mm: Add new vma flag VM_LOCAL_CPU Message-ID: <20180522165641.GN12217@hirez.programming.kicks-ass.net> References: <0efb5547-9250-6b6c-fe8e-cf4f44aaa5eb@netapp.com> <20180514191551.GA27939@bombadil.infradead.org> <7ec6fa37-8529-183d-d467-df3642bcbfd2@netapp.com> <20180515004137.GA5168@bombadil.infradead.org> <010001637399f796-3ffe3ed2-2fb1-4d43-84f0-6a65b6320d66-000000@email.amazonses.com> <5aea6aa0-88cc-be7a-7012-7845499ced2c@netapp.com> <50cbc27f-0014-0185-048d-25640f744b5b@linux.intel.com> <0100016388be5738-df8f9d12-7011-4e4e-ba5b-33973e5da794-000000@email.amazonses.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0100016388be5738-df8f9d12-7011-4e4e-ba5b-33973e5da794-000000@email.amazonses.com> User-Agent: Mutt/1.9.5 (2018-04-13) Sender: linux-fsdevel-owner@vger.kernel.org X-Mailing-List: linux-fsdevel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Tue, May 22, 2018 at 04:46:05PM +0000, Christopher Lameter wrote: > On Tue, 22 May 2018, Dave Hansen wrote: > > > On 05/22/2018 09:05 AM, Boaz Harrosh wrote: > > > How can we implement "Private memory"? > > > > Per-cpu page tables would do it. > > We already have that for percpu subsystem. See alloc_percpu() x86 doesn't have per-cpu page tables. And the last time I looked, percpu also didn't, it played games with staggered ranges in the vmalloc space and used the [FG]S segment offset to make it work. Doing proper per-cpu pagetables on x86 is possible, but quite involved and expensive.