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 0E5C0E81DF5 for ; Fri, 6 Oct 2023 13:02:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232378AbjJFNCd convert rfc822-to-8bit (ORCPT ); Fri, 6 Oct 2023 09:02:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37390 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232327AbjJFNCR (ORCPT ); Fri, 6 Oct 2023 09:02:17 -0400 Received: from mail-yw1-f180.google.com (mail-yw1-f180.google.com [209.85.128.180]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2DA70192; Fri, 6 Oct 2023 06:01:56 -0700 (PDT) Received: by mail-yw1-f180.google.com with SMTP id 00721157ae682-59f7cc71e2eso25983057b3.0; Fri, 06 Oct 2023 06:01:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696597315; x=1697202115; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=H0zfspsBQgNn0ppgGjBprJwMwlx+wA4oWVeHq3pcB3I=; b=c+dguzeouJCj2OUZ1ebYrMaMSOD3VevN4at7yhBPGI/6upsp68zBuS2KkXGIh4CrdO jvsUwWR3BN2sSVxPXyjocg+P049OsuvnZsEmB92FHZrkL9g+ZWkEhubVjcJK5Ei3+hOM mTKdt+Aw4dQpRPzBJ3mvzdMXrVz3DEhzaaHLnwbkT0iw1K/QZq4iKTP+D5o7Zw+sD3nG +ovJDcQwH7bkSnCwisQYJplIpjgcK3BFd6ePC+qxDL6s5naKIlJ9pZpfOl/yx7/Lnlbr 6i3DjyAu60f5Mv8iyOjpY2+tIX4T8GOIqLLpEDlf9NC5i/gHCRY4BqrnA005h8S/Sl07 J7YA== X-Gm-Message-State: AOJu0YzNz8E+rMzF+sYadpXsT6SyXhPm+P2m587zWtHEM9vr9KGsZlMK nLP3DHR9nRxzoEpLqjmVCryuY901cd3w3Q== X-Google-Smtp-Source: AGHT+IGhL5z43Lx7vqvAl0+pQm3IhKwd1W9WDPj2vDj4Zbfvn3GN3MAFJSiX91l+xTaFehvhmfFMAw== X-Received: by 2002:a0d:d690:0:b0:59b:eb64:bcc5 with SMTP id y138-20020a0dd690000000b0059beb64bcc5mr8707950ywd.8.1696597314836; Fri, 06 Oct 2023 06:01:54 -0700 (PDT) Received: from mail-yb1-f179.google.com (mail-yb1-f179.google.com. [209.85.219.179]) by smtp.gmail.com with ESMTPSA id f64-20020a0ddc43000000b0059b20231f1dsm1265692ywe.121.2023.10.06.06.01.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 06 Oct 2023 06:01:54 -0700 (PDT) Received: by mail-yb1-f179.google.com with SMTP id 3f1490d57ef6-d865854ef96so2221055276.2; Fri, 06 Oct 2023 06:01:52 -0700 (PDT) X-Received: by 2002:a25:f309:0:b0:d81:5240:679f with SMTP id c9-20020a25f309000000b00d815240679fmr6690046ybs.16.1696597309661; Fri, 06 Oct 2023 06:01:49 -0700 (PDT) MIME-Version: 1.0 References: <20230830184958.2333078-8-ankur.a.arora@oracle.com> <20230908070258.GA19320@noisy.programming.kicks-ass.net> <87zg1v3xxh.fsf@oracle.com> <87edj64rj1.fsf@oracle.com> <87zg1u1h5t.fsf@oracle.com> <20230911150410.GC9098@noisy.programming.kicks-ass.net> <87h6o01w1a.fsf@oracle.com> <20230912082606.GB35261@noisy.programming.kicks-ass.net> <87cyyfxd4k.ffs@tglx> <87led2wdj0.ffs@tglx> In-Reply-To: <87led2wdj0.ffs@tglx> From: Geert Uytterhoeven Date: Fri, 6 Oct 2023 15:01:37 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 7/9] sched: define TIF_ALLOW_RESCHED To: Thomas Gleixner Cc: Linus Torvalds , Peter Zijlstra , Ankur Arora , linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, luto@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, willy@infradead.org, mgorman@suse.de, rostedt@goodmis.org, jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com, jgross@suse.com, andrew.cooper3@citrix.com, Linux OpenRISC Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Thomas, On Tue, Sep 19, 2023 at 9:57 PM Thomas Gleixner wrote: > Though it just occured to me that there are dragons lurking: > > arch/alpha/Kconfig: select ARCH_NO_PREEMPT > arch/hexagon/Kconfig: select ARCH_NO_PREEMPT > arch/m68k/Kconfig: select ARCH_NO_PREEMPT if !COLDFIRE > arch/um/Kconfig: select ARCH_NO_PREEMPT > > So we have four architectures which refuse to enable preemption points, > i.e. the only model they allow is NONE and they rely on cond_resched() > for breaking large computations. Looks like there is a fifth one hidden: although openrisc does not select ARCH_NO_PREEMPT, it does not call preempt_schedule_irq() or select GENERIC_ENTRY? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds