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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 278A0C32793 for ; Wed, 18 Jan 2023 22:22:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229591AbjARWWW (ORCPT ); Wed, 18 Jan 2023 17:22:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229446AbjARWWV (ORCPT ); Wed, 18 Jan 2023 17:22:21 -0500 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22C825D7EB for ; Wed, 18 Jan 2023 14:22:20 -0800 (PST) Received: by mail-pj1-x102d.google.com with SMTP id gz9-20020a17090b0ec900b002290bda1b07so2703862pjb.1 for ; Wed, 18 Jan 2023 14:22:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=O0ldSOk59OSUgQEm352Q1IAMDrBH9zEdmVsSi4rhzHs=; b=d2qNB+Xf95ts7qkj9ZiaPnBajtLu/iVQiBTSgC7UnMvkJQfDG3lM4n6iSmLIyl4v3s 3rmfStEJ3hoCz/N6NCboYVr8sGHYbUaDBZ3riuhEADQvr4DF2XEVHeWld8Td+GJ5fmjE EVyonHor1Yeb/PODxfsRmDbI1c3LrbUxKulzi1mF8cBSG67LMY3hCTMFiwdjHpWfJK2d shgzG2mHfNhl/hyynoWMxuolQGRmbCAJDNJTHOL4tRjYe6lN8vDWeKVoJyb7gns8eUTM cwDr4PdGMWl+hDydjkIigOM2lQ3ewGntx3K0JC4HnXQdlZNDHs32qYzhlq/8roY3Snpe mQ9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=O0ldSOk59OSUgQEm352Q1IAMDrBH9zEdmVsSi4rhzHs=; b=WuDulQGou95molob33BC+lswI5IWafa7zBn8+Lh2hS+riE+6HhXzzX7DiNdWK+NoAt IRkDtG7wj1S53oyYOiB0MksR+x4XDCvFIjukbaBwNM/9U+MxQOxCfb103E2358HoC+V7 olji0eZGtY2dadzPPc5V90GzjDWqwauGDGHHKBnvqM9gC28l8WGVPvkrlijgk1N5bGv9 +7V5w7vSvBBjHaaNzXkYf2yQ1DjD7D0M5gLm9dZdKy+uRoKRQX0dcbDBYFKy+RbQz4SH /rwjRJYG9Hi5sOeNlqJ/9FTIVWM9j7phhYCGrTR18wFUcSP0BfHYRAIvfSSyyh8s413E XW+w== X-Gm-Message-State: AFqh2kr/gplc7naFU4mWXllkls1fr8VyiSByCwn7ozYvtlI8BX7eNsxP RrNIWtqHurm6PdiFyBAULV9R2amPoeJFyUFV X-Google-Smtp-Source: AMrXdXvRavXFFRYE14blzdZLuVmL27/NTESzDN8xeMK+lNpE66Enb5Ky51V+R/46yv36y/vDYHNI+A== X-Received: by 2002:a17:90b:368f:b0:229:1607:c830 with SMTP id mj15-20020a17090b368f00b002291607c830mr9173236pjb.25.1674080539376; Wed, 18 Jan 2023 14:22:19 -0800 (PST) Received: from smtpclient.apple (c-24-6-216-183.hsd1.ca.comcast.net. [24.6.216.183]) by smtp.gmail.com with ESMTPSA id dw13-20020a17090b094d00b00226f49eca92sm1840043pjb.28.2023.01.18.14.22.18 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 18 Jan 2023 14:22:18 -0800 (PST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3731.300.101.1.3\)) Subject: Re: [PATCH v6 3/5] lazy tlb: shoot lazies, non-refcounting lazy tlb mm reference handling scheme From: Nadav Amit In-Reply-To: <20230118080011.2258375-4-npiggin@gmail.com> Date: Wed, 18 Jan 2023 14:22:07 -0800 Cc: Andrew Morton , Andy Lutomirski , Linus Torvalds , linux-arch , linux-mm , linuxppc-dev@lists.ozlabs.org Content-Transfer-Encoding: quoted-printable Message-Id: <5F3590B8-3F25-4EFB-BE3A-D32AAAC0B2F4@gmail.com> References: <20230118080011.2258375-1-npiggin@gmail.com> <20230118080011.2258375-4-npiggin@gmail.com> To: Nicholas Piggin X-Mailer: Apple Mail (2.3731.300.101.1.3) Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org > On Jan 18, 2023, at 12:00 AM, Nicholas Piggin = wrote: >=20 > +static void do_shoot_lazy_tlb(void *arg) > +{ > + struct mm_struct *mm =3D arg; > + > + if (current->active_mm =3D=3D mm) { > + WARN_ON_ONCE(current->mm); > + current->active_mm =3D &init_mm; > + switch_mm(mm, &init_mm, current); > + } > +} I might be out of touch - doesn=E2=80=99t a flush already take place = when we free the page-tables, at least on common cases on x86? IIUC exit_mmap() would free page-tables, and whenever page-tables are freed, on x86, we do shootdown regardless to whether the target CPU TLB = state marks is_lazy. Then, flush_tlb_func() should call switch_mm_irqs_off() = and everything should be fine, no? [ I understand you care about powerpc, just wondering on the effect on = x86 ]