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Tue, 12 Sep 2023 08:24:41 -0400 X-MC-Unique: tisFaeRwOLyLW1avEpqfOA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2EDF71C06E0A; Tue, 12 Sep 2023 12:24:40 +0000 (UTC) Received: from lorien.usersys.redhat.com (unknown [10.22.17.68]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CBB282026D4B; Tue, 12 Sep 2023 12:24:38 +0000 (UTC) Date: Tue, 12 Sep 2023 08:24:37 -0400 From: Phil Auld To: Peter Zijlstra Cc: Ankur Arora , Linus Torvalds , 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, tglx@linutronix.de, 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 Subject: Re: [PATCH v2 7/9] sched: define TIF_ALLOW_RESCHED Message-ID: <20230912122437.GA51582@lorien.usersys.redhat.com> References: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230912082606.GB35261@noisy.programming.kicks-ass.net> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 X-Rspamd-Queue-Id: A1D7280024 X-Rspam-User: X-Stat-Signature: ofay7ytw9gerzs3sb1sadce6a7oo1hgu X-Rspamd-Server: rspam03 X-HE-Tag: 1694521483-755805 X-HE-Meta: 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 9bTGgHid tX+mkg18fVX7EkMw3zfSS0vgX+c1fIDCBWzNKt1wr8i8JfpKcAqmqDUNt62Uzw7wWiD3NzSHmGDTsp7QSWsGob/2cHGPfhlAuvBqPN5XMcHpKyjInHGp3++V7pOHSjYrAwBh8SQPhbC59sjgs7Fi6K1JbnjpCH8rBMBXpur92KmmVM3DtGK8h+7ypNSgmfcsBddBohPBotf/nerP3ABt1SLcV+Q== 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: On Tue, Sep 12, 2023 at 10:26:06AM +0200 Peter Zijlstra wrote: > On Mon, Sep 11, 2023 at 10:04:17AM -0700, Ankur Arora wrote: > > > > How expensive would be always having PREEMPT_COUNT=y? > > Effectively I think that is true today. At the very least Debian and > SuSE (I can't find a RHEL .config in a hurry but I would think they too) > ship with PREEMPT_DYNAMIC=y. > Yes, RHEL too. Cheers, Phil --