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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D948CF34C4 for ; Sat, 5 Oct 2024 16:15:59 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8EA196B0351; Sat, 5 Oct 2024 12:15:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 89AA36B0352; Sat, 5 Oct 2024 12:15:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7160E6B0353; Sat, 5 Oct 2024 12:15:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 523266B0351 for ; Sat, 5 Oct 2024 12:15:59 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 00538A0674 for ; Sat, 5 Oct 2024 16:15:58 +0000 (UTC) X-FDA: 82640049996.20.E3E5A99 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) by imf09.hostedemail.com (Postfix) with ESMTP id D6625140018 for ; Sat, 5 Oct 2024 16:15:56 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=infradead.org header.s=desiato.20200630 header.b="h/ow6/P1"; spf=none (imf09.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.92.199) smtp.mailfrom=peterz@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1728144782; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=hyCIjsZcXoZycF6/wP9qAmK3t+lawcUgpYpbgndQbwM=; b=esRF6CcKdWVP5X79O8XiLWcra3Paj15rhfNLZHD/qvlMxT9zP86omZ73Rye4QUbHa1R7dB C9UlQCR/zBtBQqKr9Es0ecJM5rjeC+zw+5aQ//wP+W/lkFffz6BH/zR3axNZCUrOuJlkgw DT/BeKdo98yZT2ep4fCkubhC4WPz0Ys= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=infradead.org header.s=desiato.20200630 header.b="h/ow6/P1"; spf=none (imf09.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.92.199) smtp.mailfrom=peterz@infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1728144782; a=rsa-sha256; cv=none; b=FGL+FuO7SDtVAl0C8DuLOCkVuZ2BkKYUJJWtrXZgjUlEdRvSgXXoJxrPG27ACA2ywNYiuW VAxEjH41qiiCNs7o+dH/FzbaQ8KcKXJr6hik5tZ9dMTgj7iZZn9XdKLXNzQ+is9GYw8YKx /IFsvtC8ts4K/Y060xqi7GDG/sjcQD4= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=hyCIjsZcXoZycF6/wP9qAmK3t+lawcUgpYpbgndQbwM=; b=h/ow6/P1k95fYePhOrvkJEEQx/ mV9pltad/g2CgR0mQjRGwGTnKupuNGrL7xJ9Ru5A9K8ZkxK9X9fveURcW++3LhIjLF9yuiVPDDGNI gFfpoSE0hk0WVPAwqnTDi2K+4ikDicV1ZRGBN61O9tlbzCiOnWhnP+/sDAuBfY7aImp4Bwyq/JG5X 0Rg3nbn7yc7ZRji3YizvDy59mfFG7xhuNjCg6R5RA+GTZDzQblaJtzzmlROLC+GTprqPeYedPk5CA eRAn9xXRnwg9tVuyJNTXGrvpTxRFF3LHUkWrudRIhIBVXOqLDHmSu6VtCCyIb9WEpDD9zx5f4CoE3 uETOQxjA==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1sx7RS-000000044LA-0K5U; Sat, 05 Oct 2024 16:15:38 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id B2EA6300777; Sat, 5 Oct 2024 18:15:37 +0200 (CEST) Date: Sat, 5 Oct 2024 18:15:37 +0200 From: Peter Zijlstra To: Linus Torvalds Cc: Mathieu Desnoyers , Andrew Morton , linux-kernel@vger.kernel.org, Nicholas Piggin , Michael Ellerman , Greg Kroah-Hartman , Sebastian Andrzej Siewior , "Paul E. McKenney" , Will Deacon , Boqun Feng , Alan Stern , John Stultz , Neeraj Upadhyay , Frederic Weisbecker , Joel Fernandes , Josh Triplett , Uladzislau Rezki , Steven Rostedt , Lai Jiangshan , Zqiang , Ingo Molnar , Waiman Long , Mark Rutland , Thomas Gleixner , Vlastimil Babka , maged.michael@gmail.com, Mateusz Guzik , Jonas Oberhauser , rcu@vger.kernel.org, linux-mm@kvack.org, lkmm@lists.linux.dev Subject: Re: [RFC PATCH 0/4] sched+mm: Track lazy active mm existence with hazard pointers Message-ID: <20241005161537.GB18071@noisy.programming.kicks-ass.net> References: <20241002010205.1341915-1-mathieu.desnoyers@efficios.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: D6625140018 X-Stat-Signature: mpbbzr3j6s91pype5n9bo1z7ruwkeedm X-Rspam-User: X-HE-Tag: 1728144956-127584 X-HE-Meta: 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 6q61oapL NIH3odRYg8HoLQDZIuIiaCTUUPnieAtCMPS9h2xPKAdoiJyrpUXb+n6qg7jogql+jHVP55hA1PHG/UXlIJo9Dec/iXKAppA9yUN4JKGZOAGF6R0Hh0JwHsaMcwItgwnvX184BWafxdrygeN7IBgq5nYMUww+SmI25bM0i7s/pIxMN9z8j/19lVY77j7jNfxJ6mJ02bIiXrGpakLw74KgDaDpP1Y/rxhA/swVacsVWcmHgX5Kj0apPTu6CnYl5ZQuaTtfV6pvtlD9ngrqQSxXdZGI/0EAuA607lCnO 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: List-Subscribe: List-Unsubscribe: On Wed, Oct 02, 2024 at 10:39:15AM -0700, Linus Torvalds wrote: > So I think the real issue is that "active_mm" is an old hack from a > bygone era when we didn't have the (much more involved) full TLB > tracking. I still seem to have these patches that neither Andy nor I ever managed to find time to finish: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/log/?h=x86/lazy