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_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 A7758C433E7 for ; Fri, 9 Oct 2020 01:24:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C92622242 for ; Fri, 9 Oct 2020 01:24:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hhOYy8Kj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725979AbgJIBYa (ORCPT ); Thu, 8 Oct 2020 21:24:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725857AbgJIBYa (ORCPT ); Thu, 8 Oct 2020 21:24:30 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7C86EC0613D2 for ; Thu, 8 Oct 2020 18:24:30 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id 34so5799412pgo.13 for ; Thu, 08 Oct 2020 18:24:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:message-id:from:to:cc:subject:in-reply-to:references :user-agent:mime-version; bh=r5a9Ez3pDwOZVBKI14NgkfuVO94y1JvO4+uEj27LNzI=; b=hhOYy8KjgYS8nGUfou5UEH+/rjxPf37tRJPPipSOLWiidQz6/a4+edWvNTQJJZkHhE AsvYElpB65J5e5LmkwLrgdYeo4PJmTYl9xacOuipsa0wNxZ9lVXGwldS5ENeiA6jF9WU NBPha4fgbreE8z3S/1Q24HzjvAImOCkrOh+B3ZYGCKFbUiav9E1oxs29nZ6lTN50yeKq dTntd3j/xCPS/gsJXBn/g6CtDWbZ5ADxaGh/qIdPy+5uHE2BbzjDXokPvQ5egqRLqm05 Y/Gq9KXVXfMGIS1tk9rCRxh38NgoIPf761cRr08exIQwvw/BDA4TAXwMvKMYyStY19fU 9IyA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:from:to:cc:subject:in-reply-to :references:user-agent:mime-version; bh=r5a9Ez3pDwOZVBKI14NgkfuVO94y1JvO4+uEj27LNzI=; b=QYlXzasiyIoIMt2CdWuw8j6mNSMN2wa31irBFX2aTGDwB84LPCtwBFqOLkshprfziN nDhO7Nk/cbCGM839SNyLCwOknoRILByL2Tj5Rdjiu/iiBcxB8/pYz8Vy/R+CJf5Kt2B5 uN9nz8zpcve69EZaap4ZXMNzpEH+OjgN+PkbnDFuPHfbO8wdaAPfFQed2x0JJec8OhbP U4gQWhIopZ7R+mX+6Y9jnhAKYs3/TqMfsavdKwJhgZtmVUAR0EFKtA9YHkNXd6r4ytRd 90Jt1eRJhXKXAG1tLDNGzLGZFknOEMhg1YC+yYugWsz90TTaOenU3MkLvHxi+hPofjSP p09w== X-Gm-Message-State: AOAM530p+5WPvh+yWPfbWjEA/9x7YnUruzs9pKJNa3eZzW7DjCv54j99 W04eWJOrR6NROjdpYQNgWCo= X-Google-Smtp-Source: ABdhPJy1CvPYVtvrQVvJyDSYUCuHzFMAv5eeZZnb9DaQ8rT+RldPbjHkd2Ql4xWYZ/Y/wX/16NWYfg== X-Received: by 2002:aa7:8249:0:b029:142:2501:39dd with SMTP id e9-20020aa782490000b0290142250139ddmr9923948pfn.44.1602206669750; Thu, 08 Oct 2020 18:24:29 -0700 (PDT) Received: from earth-mac.local.gmail.com (219x123x138x129.ap219.ftth.ucom.ne.jp. [219.123.138.129]) by smtp.gmail.com with ESMTPSA id v20sm185719pjh.5.2020.10.08.18.24.26 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Thu, 08 Oct 2020 18:24:29 -0700 (PDT) Date: Fri, 09 Oct 2020 10:24:09 +0900 Message-ID: From: Hajime Tazaki To: johannes@sipsolutions.net Cc: linux-um@lists.infradead.org, jdike@addtoit.com, richard@nod.at, anton.ivanov@cambridgegreys.com, tavi.purdila@gmail.com, linux-kernel-library@freelists.org, linux-arch@vger.kernel.org, retrage01@gmail.com Subject: Re: [RFC v7 07/21] um: extend arch_switch_to for alternate SUBARCH In-Reply-To: <5502f24bcdc07372fbc5ee86c700770038b041c4.camel@sipsolutions.net> References: <5502f24bcdc07372fbc5ee86c700770038b041c4.camel@sipsolutions.net> User-Agent: Wanderlust/2.15.9 (Almost Unreal) Emacs/25.3 Mule/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Thu, 08 Oct 2020 00:25:06 +0900, Johannes Berg wrote: > > On Tue, 2020-10-06 at 18:44 +0900, Hajime Tazaki wrote: > > This commit introduces additional argument of previous task when > > context switch happens. New SUBARCH can use the new information to > > switch tasks in a subarch-specific manner. > > > > The patch is particularly required by nommu mode implemented as a > > SUBARCH of UML. > > Would probably be good to already say why here? Agree. The patch is particularly required by nommu mode because it uses previous task information to control the previous thread (e.g., down semaphore, terminate thread, clean up thread flags). Something like this ? -- Hajime