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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 0CEC5C433DB for ; Mon, 1 Feb 2021 12:44:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9EE2264E9B for ; Mon, 1 Feb 2021 12:44:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9EE2264E9B 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 0C9B06B0070; Mon, 1 Feb 2021 07:44:44 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 079776B0071; Mon, 1 Feb 2021 07:44:44 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id ED1886B0073; Mon, 1 Feb 2021 07:44:43 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0078.hostedemail.com [216.40.44.78]) by kanga.kvack.org (Postfix) with ESMTP id DAA526B0070 for ; Mon, 1 Feb 2021 07:44:43 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 8A75B3631 for ; Mon, 1 Feb 2021 12:44:43 +0000 (UTC) X-FDA: 77769668046.08.seed84_2e1759b275c2 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin08.hostedemail.com (Postfix) with ESMTP id 6CBCC1819E773 for ; Mon, 1 Feb 2021 12:44:43 +0000 (UTC) X-HE-Tag: seed84_2e1759b275c2 X-Filterd-Recvd-Size: 3662 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf18.hostedemail.com (Postfix) with ESMTP for ; Mon, 1 Feb 2021 12:44:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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=iS8iy+q7Izh8AM4pbDoHtBgYLQUACj4slse1odTb8Xw=; b=m7ji0VO1MSn1lX6BI0jJ/Yb9pR 9LbSnyqEyG+WShVFDi6LLpOxh725y4TN5ZOzvkdZzaqe2VLLrMyA0w5DmjmAmnD9zsr9kHInq0sjB ii38K9XKQhFn7sOI40UlVOovRxxAgm9h9jejp9eCBLKegUodvH0TprmeRQ27HIdL/dZ9Y9TeAXH+T AH4kD9PgJxscyRe30c+nsFbhAUZbIF86CVRIvrNnDHqiAHo82ZC5vwPaZdUNJSPPkp0ldDsBPBc8P BJXcBzycInlMsr0+a7N0JA8WObI/EMjH6YDE79gmnKGPIcRn4F4Lq0ejsbhou5qIjm5vd3EqnQ2UW /oN5DJpg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1l6YZH-00Dm54-Iu; Mon, 01 Feb 2021 12:44:36 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 7D8C9303A02; Mon, 1 Feb 2021 13:44:34 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 65B2620C8E303; Mon, 1 Feb 2021 13:44:34 +0100 (CET) Date: Mon, 1 Feb 2021 13:44:34 +0100 From: Peter Zijlstra To: Nadav Amit Cc: Nicholas Piggin , LKML , Linux-MM , Andrea Arcangeli , Andrew Morton , Dave Hansen , "linux-csky@vger.kernel.org" , linuxppc-dev , linux-s390 , Andy Lutomirski , Mel Gorman , Thomas Gleixner , Will Deacon , X86 ML , Yu Zhao Subject: Re: [RFC 00/20] TLB batching consolidation and enhancements Message-ID: References: <20210131001132.3368247-1-namit@vmware.com> <1612063149.2awdsvvmhj.astroid@bobo.none> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Sun, Jan 31, 2021 at 07:57:01AM +0000, Nadav Amit wrote: > > On Jan 30, 2021, at 7:30 PM, Nicholas Piggin wrote: > > I'll go through the patches a bit more closely when they all come > > through. Sparc and powerpc of course need the arch lazy mode to get > > per-page/pte information for operations that are not freeing pages, > > which is what mmu gather is designed for. > > IIUC you mean any PTE change requires a TLB flush. Even setting up a new PTE > where no previous PTE was set, right? These are the HASH architectures. Their hardware doesn't walk the page-tables, but it consults a hash-table to resolve page translations. They _MUST_ flush the entries under the PTL to avoid ever seeing conflicting information, which will make them really unhappy. They can do this because they have TLBI broadcast. There's a few more details I'm sure, but those seem to have slipped from my mind.