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=-2.4 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT 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 0A1EAC4321D for ; Fri, 24 Aug 2018 14:18:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A6C6521523 for ; Fri, 24 Aug 2018 14:18:06 +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="n0ywQZz1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A6C6521523 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-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726569AbeHXRw4 (ORCPT ); Fri, 24 Aug 2018 13:52:56 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:44566 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726182AbeHXRwz (ORCPT ); Fri, 24 Aug 2018 13:52:55 -0400 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=vn2Bqi4GG9KMF7nFNidt/f60bbuDI8qY8gVrl8Bv9Aw=; b=n0ywQZz1hNZYyiCfiOOmv6Dwi hAaEYm6uPtUL6CAtBPa0SUxbFR48W8vQCXMxsRN5cvv9E6xp0miyz6h0qeIE8hDRbjUqOr52lPmVJ oQq2hTL4fh+TK/LANhvYHbrAwQgtYiTffyGE4GN01ZqtCzLcMbQpoC8VGlrCEqgRLrz08eX8VjkIM 7DAa79MK+AEjm+Y856ng/xT5xIqXGwbmcDT2WgTwkCKNwyVb1kNxbIfTl3H+3lLP5YDFHl4gs9glb R2XKwy9vo4+9rxfpDbmZQmwkMUNrm9eG9l2cWb85uIVx0LnlIWLSWMYjXamWHtdiM3PNWLIQV90Xm ZTe6UZ1Tw==; Received: from [24.132.217.100] (helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1ftBxs-0006Ds-KN; Fri, 24 Aug 2018 13:18:31 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id D740D2024C922; Fri, 24 Aug 2018 15:14:40 +0200 (CEST) Date: Fri, 24 Aug 2018 15:14:40 +0200 From: Peter Zijlstra To: Benjamin Herrenschmidt Cc: Linus Torvalds , Nick Piggin , Andrew Lutomirski , the arch/x86 maintainers , Borislav Petkov , Will Deacon , Rik van Riel , Jann Horn , Adin Scannell , Dave Hansen , Linux Kernel Mailing List , linux-mm , David Miller , Martin Schwidefsky , Michael Ellerman Subject: Re: [PATCH 3/4] mm/tlb, x86/mm: Support invalidating TLB caches for RCU_TABLE_FREE Message-ID: <20180824131440.GN24142@hirez.programming.kicks-ass.net> References: <20180822153012.173508681@infradead.org> <20180822154046.823850812@infradead.org> <20180822155527.GF24124@hirez.programming.kicks-ass.net> <20180823134525.5f12b0d3@roar.ozlabs.ibm.com> <776104d4c8e4fc680004d69e3a4c2594b638b6d1.camel@au1.ibm.com> <20180824083556.GI24124@hirez.programming.kicks-ass.net> <20180824131332.GM24142@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180824131332.GM24142@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 24, 2018 at 03:13:32PM +0200, Peter Zijlstra wrote: > + * HAVE_RCU_TABLE_FREE > + * > + * This provides tlb_remove_table(), to be used instead of tlb_remove_page() > + * for page directores (__p*_free_tlb()). This provides separate freeing of > + * the page-table pages themselves in a semi-RCU fashion (see comment below). > + * Useful if your architecture doesn't use IPIs for remote TLB invalidates > + * and therefore doesn't naturally serialize with software page-table walkers. > + * > + * HAVE_RCU_TABLE_INVALIDATE > + * > + * This makes HAVE_RCU_TABLE_FREE call tlb_flush_mmu_tlbonly() before freeing > + * the page-table pages. Required if you use HAVE_RCU_TABLE_FREE and your > + * architecture uses the Linux page-tables natively. Writing that also made me think we maybe should've negated that option.