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[209.85.219.175]) by smtp.gmail.com with ESMTPSA id u20-20020a81a514000000b00592236855cesm1236160ywg.61.2023.10.06.06.01.52 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 06 Oct 2023 06:01:52 -0700 (PDT) Received: by mail-yb1-f175.google.com with SMTP id 3f1490d57ef6-d8164e661abso2235251276.1 for ; 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: quoted-printable X-Rspamd-Queue-Id: BA0BEA0072 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: jnzk8fcc9pwqtat4pjnuhdkrj711jmrm X-HE-Tag: 1696597314-769363 X-HE-Meta: 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 gNJoH0jH 62Q/JB6kMyDqFT5GulCgo+Mzpln41Txniku/0egcTG/mtnzAk24hZKOQ1x+2PFZgMeqJeC4s/3HhY6hXsBLt/mDItbpA7x/cmfnlRzNKpQStHol8LiBqtdU2LOvQmOm0nXuPjrxPJKXYTLFLOLz2qFmf8yJMNyzAR/0Pr22RhNLakONKzasOk9CS4l4SnF2wAyP3BH2Wy4+6OAU0T5IMMPL4fZh/XunrYawJ7D8WwpM8U4IIF2UrBWGcDblFd+JcglbAaDG2R0eW66Q0zEVsYJvDGF+eFC7iQ+rIp4hoxblbXp+cPiXV/RTcgpdXhn6ThWx34yggleGAq8bsNNGn3yqgzUlhZ2Ta4quzPViY/P/QmsJFjoTQCCl8VWXXnL+F4dDfjdC9NG2Aefgb8gUbrYPJx6G49vIlTqaMZA0i+jxFiOONhcOu9p1IvXUtgHCaYtZ+ijl7/Ll9ovQ+pXsuCEKJ1yk8fhDrHWH3Y 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: Hi Thomas, On Tue, Sep 19, 2023 at 9:57=E2=80=AFPM 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 --=20 Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k= .org In personal conversations with technical people, I call myself a hacker. Bu= t when I'm talking to journalists I just say "programmer" or something like t= hat. -- Linus Torvalds