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X-CSE-ConnectionGUID: JyxQ8ZpwTe+CDc8zNAtj6g== X-CSE-MsgGUID: dsgCJrAeTWSki8x3KOXm4A== X-IronPort-AV: E=McAfee;i="6700,10204,11345"; a="40247133" X-IronPort-AV: E=Sophos;i="6.13,286,1732608000"; d="scan'208";a="40247133" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by orvoesa113.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Feb 2025 11:55:36 -0800 X-CSE-ConnectionGUID: QEDwI6BIQDioSNA4kmn/pQ== X-CSE-MsgGUID: Me5V3t4gT4yvmI0AE7PoUQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.13,286,1732608000"; d="scan'208";a="118649613" Received: from tjmaciei-mobl5.ger.corp.intel.com (HELO [10.125.109.21]) ([10.125.109.21]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Feb 2025 11:55:34 -0800 Message-ID: Date: Fri, 14 Feb 2025 11:55:38 -0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v11 06/12] x86/mm: use INVLPGB for kernel TLB flushes To: Peter Zijlstra Cc: Rik van Riel , x86@kernel.org, linux-kernel@vger.kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, zhengqi.arch@bytedance.com, nadav.amit@gmail.com, thomas.lendacky@amd.com, kernel-team@meta.com, linux-mm@kvack.org, akpm@linux-foundation.org, jackmanb@google.com, jannh@google.com, mhklinux@outlook.com, andrew.cooper3@citrix.com, Manali Shukla References: <20250213161423.449435-1-riel@surriel.com> <20250213161423.449435-7-riel@surriel.com> <20250214194013.GA2198@noisy.programming.kicks-ass.net> From: Dave Hansen Content-Language: en-US Autocrypt: addr=dave.hansen@intel.com; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/14/25 11:40, Peter Zijlstra wrote: > On Fri, Feb 14, 2025 at 10:35:40AM -0800, Dave Hansen wrote: >> On 2/13/25 08:13, Rik van Riel wrote: >>> - if (info->end == TLB_FLUSH_ALL) >>> + if (broadcast_kernel_range_flush(info)) >>> + ; /* Fall through. */ >>> + else if (info->end == TLB_FLUSH_ALL) >>> on_each_cpu(do_flush_tlb_all, NULL, 1); >>> else >>> on_each_cpu(do_kernel_range_flush, info, 1); >> We've got to find a better name for broadcast_kernel_range_flush(). >> Because IPIs are broadcast too. The naming makes it confusing. Why would >> be broadcast, and then start trying IPIs that are also broadcast? > IIRC the more general name is indeed broadcast tlbi; as in other > architectures use this naming to mean this very thing too. > > But yes, I see the confusion, but I don't think changing the naming > really helps a lot here :-/ Fair enough. If we don't have a better name, we can at least do: if (new_bad_name()) { new_thing(); } else { old_thing(); } My real heartburn is with: if (new_bad_name()) { new_thing(); } else if (need_thing_1()) { old_thing1(); } else { old_thing2(); } Where new and old are logically squished together.