From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from invmail4.hynix.com (exvmail4.skhynix.com [166.125.252.92]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7A6141D5CDD for ; Thu, 20 Feb 2025 23:23:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=166.125.252.92 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740093822; cv=none; b=TPqiejyc6TJ7suCVNjJlvH+AVpUIzWtjQcv2pp2bD5nZkxCgAbZq0lCm20mwnyUYKc+nhjD6togqRZBQLrwgqbeddgElA55OrOnfJJuWcsz6MVMBZ4pwBEV0FVSq/Gx40zVOqVtlwld6uPXj/Jtc8Uqp4lrQCu+tyqMLd+OMNCA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740093822; c=relaxed/simple; bh=Hr+P/lUTONRuYGjGw07pt5nCppUo+OK5T7GMh7oyyKk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GLaVXwDX1f+DzOE5Km5+oouf7jOXxtifvvJPTTSs6ik2zTo7RG0xivCauYHCkKZV4juBw0SCvg8kxrdFyrgvsv5fJG9px7lqQgU/jd643CPSRxerwMRWCeDQjV3sOT/vvfyFLCTEx2x1DMWu2PivXHk2XlAZrd0WfC++AdPhjK0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sk.com; spf=pass smtp.mailfrom=sk.com; arc=none smtp.client-ip=166.125.252.92 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-3e1ff7000001d7ae-17-67b7b976c54b Date: Fri, 21 Feb 2025 08:23:29 +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, vernhao@tencent.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, rjgolo@gmail.com Subject: Re: [RFC PATCH v12 00/26] LUF(Lazy Unmap Flush) reducing tlb numbers over 90% Message-ID: <20250220232329.GA39373@system.software.com> References: <20250220052027.58847-1-byungchul@sk.com> <8accbd91-ca59-43f8-b190-7e1ac3df5e11@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: <8accbd91-ca59-43f8-b190-7e1ac3df5e11@intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrAIsWRmVeSWpSXmKPExsXC9ZZnkW7Zzu3pBguPKlrMWb+GzeLzhn9s Fp9ePmC0eLGhndHi6/pfzBZPP/WxWFzeNYfN4t6a/6wW53etZbXYsXQfk8WlAwuYLI73HmCy mH/vM5vF5k1TmS2OT5nKaPH7B1DxyVmTWRwEPb639rF47Jx1l91jwaZSj80rtDwW73nJ5LFp VSebx6ZPk9g93p07x+5xYsZvFo95JwM93u+7yuax9ZedR+PUa2wenzfJBfBFcdmkpOZklqUW 6dslcGVMfrWCveARd8W2lj+sDYwLOLsYOTkkBEwkWnbfY+5i5ACzn/Skg4RZBFQllj7pZQax 2QTUJW7c+AlmiwDZp1YuZ+9i5OJgFvjPJHH/YStYQlggQuLJoRNMIDavgIXE74lLGUFsIYEM iWkbHrNAxAUlTs58AmYzC2hJ3Pj3kglkL7OAtMTyfxwgYU4BW4k77Z/BxogKKEsc2HacCeLM bewSyz9wQdiSEgdX3GCZwCgwC8nUWUimzkKYuoCReRWjUGZeWW5iZo6JXkZlXmaFXnJ+7iZG YDwuq/0TvYPx04XgQ4wCHIxKPLwJptvThVgTy4orcw8xSnAwK4nwttVvSRfiTUmsrEotyo8v Ks1JLT7EKM3BoiTOa/StPEVIID2xJDU7NbUgtQgmy8TBKdXAmG0Rxv+pv9xomd0fK64bSX6b b7x+2NLLXPXJLF+nQ0L9/PNVfQn8L98IVLpa22lVMKRvbnuQVxkntLTldaY0r1CJ9qYtKXG9 ZlMe/TT+35n5rNSo6svkwG5/c9bC+3Ne3OyvlP0Zdn+57Alz3u21fj+Lj0idSE+M1P+20PKL efT+OyViCsuUWIozEg21mIuKEwFFwUxXwwIAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprBIsWRmVeSWpSXmKPExsXC5WfdrFu2c3u6wYfn4hZz1q9hs/i84R+b xaeXDxgtXmxoZ7T4uv4Xs8XTT30sFofnnmS1uLxrDpvFvTX/WS3O71rLarFj6T4mi0sHFjBZ HO89wGQx/95nNovNm6YyWxyfMpXR4vcPoOKTsyazOAh5fG/tY/HYOesuu8eCTaUem1doeSze 85LJY9OqTjaPTZ8msXu8O3eO3ePEjN8sHvNOBnq833eVzWPxiw9MHlt/2Xk0Tr3G5vF5k1wA fxSXTUpqTmZZapG+XQJXxuRXK9gLHnFXbGv5w9rAuICzi5GDQ0LAROJJT3oXIycHi4CqxNIn vcwgNpuAusSNGz/BbBEg+9TK5exdjFwczAL/mSTuP2wFSwgLREg8OXSCCcTmFbCQ+D1xKSOI LSSQITFtw2MWiLigxMmZT8BsZgEtiRv/XjKB7GUWkJZY/o8DJMwpYCtxp/0z2BhRAWWJA9uO M01g5J2FpHsWku5ZCN0LGJlXMYpk5pXlJmbmmOoVZ2dU5mVW6CXn525iBMbXsto/E3cwfrns fohRgINRiYc3wXR7uhBrYllxZe4hRgkOZiUR3rb6LelCvCmJlVWpRfnxRaU5qcWHGKU5WJTE eb3CUxOEBNITS1KzU1MLUotgskwcnFINjNKbX24SE1x3fcu1I8/nshUfv2nX8FZ5gdUb6Q28 d8oU9qc35zpu8H3X22R27c2MBUXy5Q199bfWhwp0pUr/698z8Upor9T7z5LJX/ecmcGzaYPy 7FN/rBlOzd/gZZ+zNZphWb37jerETsGfX6Ywi6zT8Co3n3th6sq33LEpPqsnXzaeWzhVx1+J pTgj0VCLuag4EQDIkqvyqwIAAA== X-CFilter-Loop: Reflected On Thu, Feb 20, 2025 at 07:15:44AM -0800, Dave Hansen wrote: > On 2/19/25 21:20, Byungchul Park wrote: > > I'm posting the latest version so that anyone can try luf mechanism if > > wanted by any chance. However, I tagged RFC again because there are > > still issues that should be resolved to merge to mainline: > > I don't see anything fundamentally different here from the last 11 > versions. I think the entire approach is dangerous and basically makes > things impossible to debug. It's not clear that some of the failure > scenarios that I've brought up in the past have actually been fixed. Respect your opinion. > What I've said here still stands: > > > https://lore.kernel.org/all/fab1dd64-c652-4160-93b4-7b483a8874da@intel.com/ > > > I think tglx would call all of this "tinkering". The approach to this > > series is to "fix" narrow, specific cases that reviewers point out, make > > it compile, then send it out again, hoping someone will apply it. > > > > So, for me, until the approach to this series changes: NAK, for x86. > > Andrew, please don't take this series. Or, if you do, please drop the > > patch enabling it on x86. > > I think I'd also like to stop being cc'd on this. If LUF is merged into I will un-cc you from the next spin. Byungchul > mainline and proven to work on arm64 or riscv for a year, I'd be happy > to take another look at enabling it on x86. I think that's just about > the only thing that would make me reconsider.