From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A396945BE1 for ; Fri, 15 Dec 2023 19:39:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="wLzyA2Ai"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="HZqTHUC7" From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1702669188; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=CcyJTwzRD6ZFeNFzISSaZIcUm8lkKFqGiYWHcX6xjis=; b=wLzyA2AigQbDtTqznVR9C0OEcdHnoVJ/+IHjKYttLOIMVoE06A2+qwqRkYgO4b1XHViqWy 2dJG39jxo+T1BC3NMg+aLhjlateaoQfxqUmOt+OaFfE7qaJ3LXEsbXGLHGq18JuFf/snwA UmW9ndno71UMfIaw8DDg5g23mdmgyANhMiveHE/PFsZCsZwj+FJ2tAxAj91Gg+Jxrist+3 NUiXZV4vRPzLM8n5kWTAdA/WffaopU3Eaz6S3Wc6sfEiy9bA2m4b6wgaONzeKu144tmO99 OUSUf/egUkym0tywFEOOtSyee+DAMXCbgQElFx2xudqJ7z/OlZxlLh9NaQ64TQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1702669188; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=CcyJTwzRD6ZFeNFzISSaZIcUm8lkKFqGiYWHcX6xjis=; b=HZqTHUC71Oj38kp7+eZPHiuAKQ9G7Q95NThHnWfkU0/Gtqf/N6VLOUzGVJApINMQAAo+qk SaDsfArhauICt5Dg== To: wangxiaoming321 , peterz@infradead.org, linux-kernel@vger.kernel.org Cc: wangxiaoming321 Subject: Re: [PATCH] kernel/cpu: The number of CPUHP_AP_ONLINE_DYN (30) is too small that stops the new dynamic states hotplug. In-Reply-To: <20231212025235.775986-1-xiaoming.wang@intel.com> References: <20231212025235.775986-1-xiaoming.wang@intel.com> Date: Fri, 15 Dec 2023 20:39:47 +0100 Message-ID: <87o7ermf0c.ffs@tglx> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Tue, Dec 12 2023 at 10:52, wangxiaoming321 wrote: The subject line has a two issues: 1) the prefix is wrong. See https://www.kernel.org/doc/html/latest/process/maintainer-tip.html#patch-subject You find further information about changelogs there and in other parts of the documentation 2) The sentence is too long and incomprehensible. > 144: perf/x86/cstate:online ... > 195: online I have no idea what this number salad is trying to tell me. Changelogs need to explain the problem they are trying to solve. This listing of hotplug states is not an explanation and completely useless as it even contains an entry which do not exist: > 191: ia64/sep5:online Even if it would exist a ia64 hotplug callback is hardly relevant on x86, right? Also the fixed entries e.g. workqueue and RCU/tree are irrelevant for what you are trying to describe. So what you really want to say is something like this: cpu/hotplug: Increase the number of dynamic states The dynamically allocatable hotplug state space can be exhausted by the existing drivers and infrastructure which install CPU hotplug states dynamically. That prevents new drivers and infrastructure from installing dynamically allocated states. Increase the size of the CPUHP_AP_ONLINE_DYN state by 10 to make room. At least that's what I oracled out of your "changelog". Hmm? Thanks, tglx