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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 261B6C433DF for ; Thu, 13 Aug 2020 21:36:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B554720768 for ; Thu, 13 Aug 2020 21:36:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="OomA2hoQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B554720768 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 191E38D0002; Thu, 13 Aug 2020 17:36:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 141B26B0027; Thu, 13 Aug 2020 17:36:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0578B8D0002; Thu, 13 Aug 2020 17:36:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0093.hostedemail.com [216.40.44.93]) by kanga.kvack.org (Postfix) with ESMTP id E69286B0024 for ; Thu, 13 Aug 2020 17:36:57 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id A44F58248068 for ; Thu, 13 Aug 2020 21:36:57 +0000 (UTC) X-FDA: 77146855674.08.join84_5b0e33626ff7 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin08.hostedemail.com (Postfix) with ESMTP id 6B5CB1819E76C for ; Thu, 13 Aug 2020 21:36:57 +0000 (UTC) X-HE-Tag: join84_5b0e33626ff7 X-Filterd-Recvd-Size: 2382 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf02.hostedemail.com (Postfix) with ESMTP for ; Thu, 13 Aug 2020 21:36:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=7fWn8gbH7OngjDkU5Iy7SVxH91T/zZwGUSoY4uuguys=; b=OomA2hoQQO9phLuXJbJnHe05xH tIirJEhABC3QLAcqVr2RgdhQBLiJIUfNV60MMDKGQk0Swsz8z8kNYhxZmi/h4Sg6sKCujvt+MMc9D MyUwTljpMHpiQEk608pe3kUC2tLzVLPdy4msK1Kv1NhYdJs4us2AT4wKwHGweqXvrpy6QGYRtBDFM uFQbm/lKPb1kSU9s3twSWqSalI4yzDRlKvxWwLx1VZVcBZDyzl0VcNiICrxSoGUaPXkvDo0ozvv2a ARiIgvHOF1O9Ds1sZA0XYWAgE0WbKc4fcroqQawCXql8mrWqPxSIO+GMIbUqv1Zyz1NSPQeeCayLH CeE8Kgkw==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k6Ktj-0004OK-Oh; Thu, 13 Aug 2020 21:36:31 +0000 Date: Thu, 13 Aug 2020 22:36:31 +0100 From: Matthew Wilcox To: Mike Rapoport Cc: Jessica Clarke , John Paul Adrian Glaubitz , Tony Luck , linux-ia64@vger.kernel.org, Anatoly Pugachev , Sergei Trofimovich , linux-mm@kvack.org, Frank Scheiner , Mike Rapoport Subject: Re: [PATCH v5] arch/ia64: Restore arch-specific pgd_offset_k implementation Message-ID: <20200813213631.GQ17456@casper.infradead.org> References: <20200813205521.5405-1-rppt@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200813205521.5405-1-rppt@kernel.org> X-Rspamd-Queue-Id: 6B5CB1819E76C X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 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 Thu, Aug 13, 2020 at 11:55:21PM +0300, Mike Rapoport wrote: > +/* > + * In the kernel's mapped region we know everything is in region number 5, so > + * as an optimisation its PGD already points to the area for that region. Is it actually an optimisation? Are there any benchmarks where this makes any difference whatsoever? Or should the comment be closer to /* ia64 is gratuitously different. Cope with it. */ I might suggest that pgd be changed to be the same as every other pgd in the system, and every other architecture.