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X-CSE-ConnectionGUID: 3bcsT0nxTKyQd+hWguz6aQ== X-CSE-MsgGUID: 74M6bCHoS8Kb5rD/IuZLSA== X-IronPort-AV: E=McAfee;i="6800,10657,11659"; a="69061901" X-IronPort-AV: E=Sophos;i="6.21,198,1763452800"; d="scan'208";a="69061901" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by orvoesa108.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jan 2026 09:06:33 -0800 X-CSE-ConnectionGUID: WDoP2JgATO+WJHK50upKRA== X-CSE-MsgGUID: O5Ym+/x0QLOsXPLtcUC9jA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,198,1763452800"; d="scan'208";a="202499243" Received: from rchatre-mobl4.amr.corp.intel.com (HELO [10.125.109.1]) ([10.125.109.1]) by fmviesa009-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jan 2026 09:06:31 -0800 Message-ID: Date: Sat, 3 Jan 2026 09:06:30 -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 v2 0/3] skip redundant TLB sync IPIs To: Lance Yang , "David Hildenbrand (Red Hat)" Cc: will@kernel.org, aneesh.kumar@kernel.org, npiggin@gmail.com, peterz@infradead.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, arnd@arndb.de, lorenzo.stoakes@oracle.com, ziy@nvidia.com, baolin.wang@linux.alibaba.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, ioworker0@gmail.com, shy828301@gmail.com, riel@surriel.com, jannh@google.com, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org References: <20251229145245.85452-1-lance.yang@linux.dev> <1b27a3fa-359a-43d0-bdeb-c31341749367@kernel.org> 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 1/3/26 00:39, Lance Yang wrote: ... > Maybe we could do that as a follow-up. I'd like to keep things simple > for now, so we just add a bool property to skip redundant TLB sync IPIs > on systems without INVLPGB support. It's not just INVLPGB support. Take a look at hyperv_flush_tlb_multi(), for instance. It can eventually land back in native_flush_tlb_multi(), but would also "fail" the pv_ops check in all cases. It's not that Hyper-V performance is super important, it just that the semantics of the chosen approach here are rather complicated. > Then we could add the mm->context (or something similar) tracking later > to handle things more precisely. > > Anyway, I'm open to going straight to the mm->context approach as well > and happy to do that instead :D I'd really like to see what an mm->context approach looks like before we go forward with what is being proposed here. Is there some kind of hurry to get this done immediately?