From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B561EC4332F for ; Fri, 10 Nov 2023 01:09:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345569AbjKJBJC (ORCPT ); Thu, 9 Nov 2023 20:09:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345556AbjKJBJA (ORCPT ); Thu, 9 Nov 2023 20:09:00 -0500 Received: from invmail4.hynix.com (exvmail4.hynix.com [166.125.252.92]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6978CBC for ; Thu, 9 Nov 2023 17:08:58 -0800 (PST) X-AuditID: a67dfc5b-d85ff70000001748-66-654d82a977b2 Date: Fri, 10 Nov 2023 10:08:52 +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: <20231110010852.GB72073@system.software.com> References: <20231109045908.54996-1-byungchul@sk.com> <64cb078b-d2e7-417f-8125-b38d423163ce@intel.com> 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+NgFtrAIsWRmVeSWpSXmKPExsXC9ZZnke7KJt9Ug0MXFSzmrF/DZvF5wz82 i08vHzBavNjQzmjxdf0vZounn/pYLC7vmsNmcW/Nf1aL87vWslrsWLqPyeLSgQVMFtd3PWS0 ON57gMli86apzBa/fwDVzZliZXFy1mQWB0GP7619LB4LNpV6bF6h5bF4z0smj02rOtk8Nn2a xO7x7tw5do8TM36zeOx8aOkx72Sgx/t9V9k8tv6y8/i8Sc7j3fy3bAF8UVw2Kak5mWWpRfp2 CVwZyz7sZivo4Ki49PwJcwPjKrYuRk4OCQETiZmNp1lh7EOzvrCA2CwCqhLrXyxgArHZBNQl btz4yQxiiwDZp1YuZ+9i5OJgFmhilri2fjNYs7CAu8SuU3fAingFLCTObZrMCGILCWRIHH89 hx0iLihxcuYTsAXMAloSN/69BFrAAWRLSyz/xwES5hSwldjf8AzsNlEBZYkD244zgeySENjE LrH4108WiEMlJQ6uuMEygVFgFpKxs5CMnYUwdgEj8ypGocy8stzEzBwTvYzKvMwKveT83E2M wHhcVvsnegfjpwvBhxgFOBiVeHgvXPdJFWJNLCuuzD3EKMHBrCTCe8EEKMSbklhZlVqUH19U mpNafIhRmoNFSZzX6Ft5ipBAemJJanZqakFqEUyWiYNTqoGxqPrTD0XpH802wbm7jVefnB3c vsJjgmDbvqk7Lzw9mzN3c2Wo4Pz/71gkcr1MUkV+X3BZ+DDv2+uqCd9ePMuv2T+ftY5P4e3L ojsL8/zFJzDpF2p4XT0fHnvpz8UX+zcErZ2e0/LsraRGjWqGBs8c9pvyN21+Gto53Jv/puni ppOGVw9bfZDsVmIpzkg01GIuKk4EALWTFe3DAgAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprOIsWRmVeSWpSXmKPExsXC5WfdrLuyyTfVYOccAYs569ewWXze8I/N 4tPLB4wWLza0M1p8Xf+L2eLppz4Wi8NzT7JaXN41h83i3pr/rBbnd61ltdixdB+TxaUDC5gs ru96yGhxvPcAk8XmTVOZLX7/AKqbM8XK4uSsySwOQh7fW/tYPBZsKvXYvELLY/Gel0wem1Z1 snls+jSJ3ePduXPsHidm/Gbx2PnQ0mPeyUCP9/uusnksfvGByWPrLzuPz5vkPN7Nf8sWwB/F ZZOSmpNZllqkb5fAlbHsw262gg6OikvPnzA3MK5i62Lk5JAQMJE4NOsLC4jNIqAqsf7FAiYQ m01AXeLGjZ/MILYIkH1q5XL2LkYuDmaBJmaJa+s3s4IkhAXcJXadugNWxCtgIXFu02RGEFtI IEPi+Os57BBxQYmTM5+ALWAW0JK48e8l0AIOIFtaYvk/DpAwp4CtxP6GZ2D3iAooSxzYdpxp AiPvLCTds5B0z0LoXsDIvIpRJDOvLDcxM8dUrzg7ozIvs0IvOT93EyMwupbV/pm4g/HLZfdD jAIcjEo8vBeu+6QKsSaWFVfmHmKU4GBWEuG9YAIU4k1JrKxKLcqPLyrNSS0+xCjNwaIkzusV npogJJCeWJKanZpakFoEk2Xi4JRqYLzgaTtJ99Yq28M+v9ZX9S917HCpYU+7MLsv/LtuS9dm p4LvV1/WTZ1unpWYtFF3zc8XcQyTymK2CDle/3z/bJev6ImDzet+OR/+X2f/YEXN8bBntTbb aioZolbo+yu+W/xdp/1pSPLpKw0B5+41rtP28lX+cDt798te1uUHfieyZqZ8eF4yM0KJpTgj 0VCLuag4EQBQQNp5qgIAAA== X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. > > I'd really suggest not sending any more of these out until those issues > are rectified. I know I definitely won't be reviewing them in this state. Make sense. Lemme think it more and improve it. Byungchul