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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 51120C4CECE for ; Mon, 14 Oct 2019 21:48:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EB40E21721 for ; Mon, 14 Oct 2019 21:48:16 +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="K9uVe0jE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EB40E21721 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 49F258E0005; Mon, 14 Oct 2019 17:48:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 44FA98E0001; Mon, 14 Oct 2019 17:48:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 365F58E0005; Mon, 14 Oct 2019 17:48:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0146.hostedemail.com [216.40.44.146]) by kanga.kvack.org (Postfix) with ESMTP id 14E7A8E0001 for ; Mon, 14 Oct 2019 17:48:16 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 62D08181AEF10 for ; Mon, 14 Oct 2019 21:48:15 +0000 (UTC) X-FDA: 76043728950.28.tooth02_65115d668ee01 X-HE-Tag: tooth02_65115d668ee01 X-Filterd-Recvd-Size: 3388 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf23.hostedemail.com (Postfix) with ESMTP for ; Mon, 14 Oct 2019 21:48:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=r8+y9y2pf6LTBiDmD8ROJU1496EBIFF0Ze6tIupxL2U=; b=K9uVe0jEoGlpWh2+YYpxbI82j 94gnr5sqHxIwpTw7qYu9rgfRaZl4hH99mdv01m0cP3vrveXCqWMbu3ZOxIuicu0opBhchEnfJ754+ tqq82Ow5YhOUV3NxjE1w6it9c9Krox4SATn0EGSDqWlB070ssRUW72rEoyS5vPMhkhK6bO9r39fUQ FyJOYdNh26zruSPPtzvxp98VsxBG+n53UoAE2i2rLN7R9BE4HdAvOOwK5krbXZwIc2olcX2J0hg/F UzZcIMDRc+R+PXNRxkRmwOsdkhXd35e8h+NXhKfbEA3rXf4TKvIAuoMdw4ANTP2TMXgFDJdI4WTJq YnL7y66EQ==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1iK8CA-0001s1-5B; Mon, 14 Oct 2019 21:48:02 +0000 Date: Mon, 14 Oct 2019 14:48:02 -0700 From: Matthew Wilcox To: Linus Torvalds Cc: Vineet Gupta , linux-arch , Arnd Bergmann , Peter Zijlstra , "Aneesh Kumar K . V" , Linux Kernel Mailing List , Nick Piggin , Linux-MM , Andrew Morton , linux-snps-arc@lists.infradead.org, Will Deacon , "Kirill A . Shutemov" Subject: Re: [RFC] asm-generic/tlb: stub out pmd_free_tlb() if __PAGETABLE_PMD_FOLDED Message-ID: <20191014214802.GA32665@bombadil.infradead.org> References: <20191011121951.nxna6hruuskvdxod@box> <20191011223818.7238-1-vgupta@synopsys.com> <8bfd023b-5c00-8355-fd0f-3b4377951e6c@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) 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, Oct 14, 2019 at 01:38:34PM -0700, Linus Torvalds wrote: > And now I've said pgd/pud/p4d/pmd so many times that I've confused > myself and think I'm wrong again, and I think that historically - > originally - we always had a pgd, and then the pmd didn't exist > because it was folded into it. That makes sense from a x86 naming > standpoint. Then x86 _did_ get a pmd, and then we added more levels in > between, and other architectures did things differently. Oh my goodness. Thank you for writing all this out and finally getting to this point. I was reading the whole thing thinking "This is different from what I remember" and then you got here. This explains so much about how our MM does/doesn't work, and it's not just me that's confused ;-)