From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from invmail4.hynix.com (exvmail4.hynix.com [166.125.252.92]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 34122440D for ; Mon, 15 Jan 2024 07:58:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sk.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sk.com X-AuditID: a67dfc5b-d6dff70000001748-6c-65a4e5960a1f Date: Mon, 15 Jan 2024 16:58:09 +0900 From: Byungchul Park To: Dave Hansen Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel_team@skhynix.com, akpm@linux-foundation.org, ying.huang@intel.com, namit@vmware.com, xhao@linux.alibaba.com, mgorman@techsingularity.net, hughd@google.com, willy@infradead.org, david@redhat.com, peterz@infradead.org, luto@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com Subject: Re: [v4 0/3] Reduce TLB flushes under some specific conditions Message-ID: <20240115075809.GB56305@system.software.com> References: <20231109045908.54996-1-byungchul@sk.com> <64cb078b-d2e7-417f-8125-b38d423163ce@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <64cb078b-d2e7-417f-8125-b38d423163ce@intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrPIsWRmVeSWpSXmKPExsXC9ZZnke60p0tSDdr+WlrMWb+GzeLzhn9s Fp9ePmC0eLGhndHi6/pfzBZPP/WxWFzeNYfN4t6a/6wW53etZbXYsXQfk8WlAwuYLK7vesho cbz3AJPF5k1TmS1+/wCqmzPFyuLkrMksDoIe31v7WDwWbCr12LxCy2PxnpdMHptWdbJ5bPo0 id3j3blz7B4nZvxm8dj50NJj3slAj/f7rrJ5bP1l5/F5k5zHu/lv2QL4orhsUlJzMstSi/Tt Ergy9v+uLWhlr5i15SFjA+MR1i5GTg4JAROJuccvMMLY/0+2s4HYLAKqEgf+XGECsdkE1CVu 3PjJDGKLANmnVi5n72Lk4mAWaGKWuLZ+M9ggYQF3iV2n7oAV8QpYSFydsRusWUggQ+L46zns EHFBiZMzn7CA2MwCWhI3/r0EquEAsqUllv/jAAlzCthK7G94BnaDqICyxIFtx5lAdkkIrGOX mPLqITPEoZISB1fcYJnAKDALydhZSMbOQhi7gJF5FaNQZl5ZbmJmjoleRmVeZoVecn7uJkZg NC6r/RO9g/HTheBDjAIcjEo8vD/+Lk4VYk0sK67MPcQowcGsJMJbfWdJqhBvSmJlVWpRfnxR aU5q8SFGaQ4WJXFeo2/lKUIC6YklqdmpqQWpRTBZJg5OqQZGeUUOD7bL169ZqfoIm9U3+qSK 6Oyb9iOsRDpdame0Y9ReF0a2W6/ke+LMLRVfNn7r9ps1mSOSaU++cKC/bl5i1O4ZrkffvwnN rpnOGrwpgl+wIfXJ3MtF9/e/Zt/Qdd487aOIUFrFlwcnTtqZxJ2ZPy95peS8H2c+HK5n+v59 55YfdpPDlospsRRnJBpqMRcVJwIA74qV9MICAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprGIsWRmVeSWpSXmKPExsXC5WfdrDvt6ZJUgxvbdSzmrF/DZvF5wz82 i08vHzBavNjQzmjxdf0vZounn/pYLA7PPclqcXnXHDaLe2v+s1qc37WW1WLH0n1MFpcOLGCy uL7rIaPF8d4DTBabN01ltvj9A6huzhQri5OzJrM4CHl8b+1j8ViwqdRj8wotj8V7XjJ5bFrV yeax6dMkdo93586xe5yY8ZvFY+dDS495JwM93u+7yuax+MUHJo+tv+w8Pm+S83g3/y1bAH8U l01Kak5mWWqRvl0CV8b+37UFrewVs7Y8ZGxgPMLaxcjJISFgIvH/ZDsbiM0ioCpx4M8VJhCb TUBd4saNn8wgtgiQfWrlcvYuRi4OZoEmZolr6zeDNQsLuEvsOnUHrIhXwELi6ozdYM1CAhkS x1/PYYeIC0qcnPmEBcRmFtCSuPHvJVANB5AtLbH8HwdImFPAVmJ/wzOwG0QFlCUObDvONIGR dxaS7llIumchdC9gZF7FKJKZV5abmJljqlecnVGZl1mhl5yfu4kRGFvLav9M3MH45bL7IUYB DkYlHt4ffxenCrEmlhVX5h5ilOBgVhLhrb6zJFWINyWxsiq1KD++qDQntfgQozQHi5I4r1d4 aoKQQHpiSWp2ampBahFMlomDU6qB0XBH0AqTgptvGY8pH5AIcS8svSnsdeVYv4q8t7q494OV LcHPk+TnnXhRqswXef5Lx33Fy1dsNaOVmkWbd6ixXNxae0xzwhWemXzqLHk3vsQtL668kVon luWY6vJJYabsrAkKkqdXLNmzXys15v0J64Ps24srfG32p/DPLd3z4lTyurSQT8nxSizFGYmG WsxFxYkAiMxD0akCAAA= X-CFilter-Loop: Reflected On Thu, Nov 09, 2023 at 06:26:08AM -0800, Dave Hansen wrote: > On 11/8/23 20:59, Byungchul Park wrote: > > Can you believe it? I saw the number of TLB full flush reduced about > > 80% and iTLB miss reduced about 50%, and the time wise performance > > always shows at least 1% stable improvement with the workload I tested > > with, XSBench. However, I believe that it would help more with other > > ones or any real ones. It'd be appreciated to let me know if I'm missing > > something. > > I see that you've moved a substantial amount of code out of arch/x86. > That's great. > > But there doesn't appear to be any improvement in the justification or > performance data. The page flag is also here, which is horribly frowned > upon. It's an absolute no-go with this level of justification. Okay. I won't use an additional page flag anymore from migrc v5. Thanks. Byungchul