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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 8DE87C2D0E4 for ; Sun, 15 Nov 2020 18:58:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1A33C2225B for ; Sun, 15 Nov 2020 18:58:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="xy4LEmo+"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Qd+mE+Op" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A33C2225B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 43EA86B0036; Sun, 15 Nov 2020 13:58:56 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3EF136B005D; Sun, 15 Nov 2020 13:58:56 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 304E76B0068; Sun, 15 Nov 2020 13:58:56 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0243.hostedemail.com [216.40.44.243]) by kanga.kvack.org (Postfix) with ESMTP id 003006B0036 for ; Sun, 15 Nov 2020 13:58:55 -0500 (EST) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 95F03181AEF1E for ; Sun, 15 Nov 2020 18:58:55 +0000 (UTC) X-FDA: 77487564630.29.actor65_0c08f1927322 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin29.hostedemail.com (Postfix) with ESMTP id 7D74118086CAC for ; Sun, 15 Nov 2020 18:58:55 +0000 (UTC) X-HE-Tag: actor65_0c08f1927322 X-Filterd-Recvd-Size: 3157 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf05.hostedemail.com (Postfix) with ESMTP for ; Sun, 15 Nov 2020 18:58:54 +0000 (UTC) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1605466732; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=lM+Tn3Xn9woEdnNA0HLgCq49xITc6UQA2eZ6y/GPCoI=; b=xy4LEmo+jlz0Jq+PPQQnClThn2BQPP2VK/gIjQk5I2KRckjCj7Drnsna9lksUk/ITpwuTz sVtPgVlXN/2E2E21zA1k079EKJvTIkc7ENv9Jftd7gQE3ubTJ+lhaEDKmxMaSAqzp0Qeap v+5xHxFsmZoQ2Q87P28QIuKhRzXpFQXzNYo3nNUHhM6WSWz53AGt9Lsfov+OPHZsGOadaf k3qd+kTh6nngia5Ch9pnnaw/EQOevyqIT94eHQHLhmzS7VS3uXOdO+MtcdYkJjDzK6r80k kNKu19wadW/FwBvJKeK2w/r0iIoagaFIN0IbDi6oaV3zya4QGqNDLRPDOUbzEw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1605466732; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=lM+Tn3Xn9woEdnNA0HLgCq49xITc6UQA2eZ6y/GPCoI=; b=Qd+mE+OpsEvFKxHyQ2CT5n9hPmnIwB1brU84Jw4XCXyD0Jok+oJLKNA01C+Xh8tdkbW36v QVxMvbDeCbijnIDw== To: ira.weiny@intel.com, Ingo Molnar , Borislav Petkov , Andy Lutomirski , Peter Zijlstra , Dave Hansen Cc: Ira Weiny , x86@kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , Fenghua Yu , linux-doc@vger.kernel.org, linux-nvdimm@lists.01.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Dan Williams , Greg KH Subject: Re: [PATCH V3 05/10] x86/entry: Pass irqentry_state_t by reference In-Reply-To: <20201106232908.364581-6-ira.weiny@intel.com> References: <20201106232908.364581-1-ira.weiny@intel.com> <20201106232908.364581-6-ira.weiny@intel.com> Date: Sun, 15 Nov 2020 19:58:52 +0100 Message-ID: <87mtzi8n0z.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain 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: Ira, On Fri, Nov 06 2020 at 15:29, ira weiny wrote: Subject prefix wants to 'entry:'. This changes generic code and the x86 part is just required to fix the generic code change. > Currently struct irqentry_state_t only contains a single bool value > which makes passing it by value is reasonable. However, future patches > propose to add information to this struct, for example the PKRS > register/thread state. > > Adding information to irqentry_state_t makes passing by value less > efficient. Therefore, change the entry/exit calls to pass irq_state by > reference. The PKRS muck needs to add an u32 to that struct. So how is that a problem? The resulting struct still fits into 64bit which is by far more efficiently passed by value than by reference. So which problem are you solving here? Thanks tglx