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 X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B01DC54FC9 for ; Tue, 21 Apr 2020 13:11:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CA899206F4 for ; Tue, 21 Apr 2020 13:11:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Rv/hUG5V" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CA899206F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 61CDF8E0007; Tue, 21 Apr 2020 09:11:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5CD0A8E0003; Tue, 21 Apr 2020 09:11:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4947F8E0007; Tue, 21 Apr 2020 09:11:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0228.hostedemail.com [216.40.44.228]) by kanga.kvack.org (Postfix) with ESMTP id 2F4378E0003 for ; Tue, 21 Apr 2020 09:11:06 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id D8588180AD806 for ; Tue, 21 Apr 2020 13:11:05 +0000 (UTC) X-FDA: 76731897690.19.shop73_60d61b7d45052 X-HE-Tag: shop73_60d61b7d45052 X-Filterd-Recvd-Size: 2742 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf47.hostedemail.com (Postfix) with ESMTP for ; Tue, 21 Apr 2020 13:11:05 +0000 (UTC) Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0DAD82068F; Tue, 21 Apr 2020 13:11:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587474664; bh=iZtYZnqW7KYibljByYmwIr2bMYYIuK/p/5URYQoVr0w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Rv/hUG5VOtnvREDmZaNjRFORwuUAApvR0qIRVH5O2zXq6hmMXb3NGi3Waxk5hXP71 P+vMqDEidsfu6Chlk4n/QbuYXEmZklwWMcEW/XAIW5gG3dT4MwqbwDH5ztAIa1h0tr bP0bqgdh7oDQJG9deT5fyxWTg2Cmst5sgFMwPKRM= Date: Tue, 21 Apr 2020 14:10:58 +0100 From: Will Deacon To: Michal Hocko Cc: Vlastimil Babka , Prathu Baronia , catalin.marinas@arm.com, alexander.duyck@gmail.com, chintan.pandya@oneplus.com, akpm@linux-foundation.org, linux-mm@kvack.org, gregkh@linuxfoundation.com, gthelen@google.com, jack@suse.cz, ken.lin@oneplus.com, gasine.xu@oneplus.com, ying.huang@intel.com, mark.rutland@arm.com Subject: Re: [PATCH v2] mm: Optimized hugepage zeroing & copying from user Message-ID: <20200421131058.GB17875@willie-the-truck> References: <20200414153829.GA15230@oneplus.com> <87r1wpzavo.fsf@yhuang-dev.intel.com> <20200419155856.dtwxomdkyujljdfi@oneplus.com> <87k12bt3ff.fsf@yhuang-dev.intel.com> <20200421093621.3fuptvf2qbyfzwfz@oneplus.com> <20200421100932.GC17256@willie-the-truck> <20200421130040.GH27314@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200421130040.GH27314@dhcp22.suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Apr 21, 2020 at 03:00:40PM +0200, Michal Hocko wrote: > On Tue 21-04-20 14:47:13, Vlastimil Babka wrote: > [...] > > In that case the generic implementation should be just reverted to be simple and > > not assume any (micro)architectural details. If any architecture wants an > > optimized version they could add it opt-in, and justifify it by using real > > workloads, not microbenchmarks. > > Exactly! And I have requested that already with no response. So can we > simply go and make the current implementation x86 specific and > reintroduce the previous one as a default? Works for me as well, I just didn't want a special arm64 implementation based on one specific micro-architecture. Will