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X-CSE-ConnectionGUID: dd5BhvQUSgWPm0clVKAAIg== X-CSE-MsgGUID: rOzCVmihQFau4FoTjZsh6A== X-IronPort-AV: E=McAfee;i="6800,10657,11465"; a="52370452" X-IronPort-AV: E=Sophos;i="6.16,241,1744095600"; d="scan'208";a="52370452" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by orvoesa110.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jun 2025 08:06:19 -0700 X-CSE-ConnectionGUID: SZj33IYFShmgbOY5t1rRhQ== X-CSE-MsgGUID: F5pdNtJpSnOLhlT3EwPXCg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,241,1744095600"; d="scan'208";a="148405313" Received: from msatwood-mobl.amr.corp.intel.com (HELO [10.125.108.25]) ([10.125.108.25]) by fmviesa007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jun 2025 08:06:14 -0700 Message-ID: <5d3e4538-9757-4d6e-bed1-900c9859d860@intel.com> Date: Mon, 16 Jun 2025 08:06:12 -0700 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 v4 00/13] x86/mm: Add multi-page clearing To: Ankur Arora , linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org Cc: akpm@linux-foundation.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, mjguzik@gmail.com, luto@kernel.org, peterz@infradead.org, acme@kernel.org, namhyung@kernel.org, tglx@linutronix.de, willy@infradead.org, jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com References: <20250616052223.723982-1-ankur.a.arora@oracle.com> 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 6/15/25 22:22, Ankur Arora wrote: > This series adds multi-page clearing for hugepages, improving on the > current page-at-a-time approach in two ways: > > - amortizes the per-page setup cost over a larger extent > - when using string instructions, exposes the real region size to the > processor. A processor could use that as a hint to optimize based > on the full extent size. AMD Zen uarchs, as an example, elide > allocation of cachelines for regions larger than L3-size. Have you happened to do any testing outside of 'perf bench'?