Received: by 2002:a05:6a10:9848:0:0:0:0 with SMTP id x8csp239242pxf; Wed, 17 Mar 2021 21:39:14 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyCowpFueAG2G5yjw7hV9zGVv1HujWHL1dkSaKBV3Q5wjEj9xZrvXlFgDpbLfT+ekvDunZt X-Received: by 2002:a17:907:628a:: with SMTP id nd10mr36244344ejc.326.1616042354601; Wed, 17 Mar 2021 21:39:14 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1616042354; cv=none; d=google.com; s=arc-20160816; b=ABcmgyUHPO0Z3J71vefMD4SR68M7sHrMHQIfLn2Hnibch37CCA1Vd0wrWqS/XxsqyT VpOASVqSfppVQCTnTXrmoOfa3aI1ejhhLqCD8A3R8daEiEQUazfSgV167NbS2tcnifNz 7iluDJbqIwlapeI0bKiexqpJAZlKk9CjC+7D10VkH+oNJEFxN1QOfgjwcqqemEuYCGaY J8U5BJPBpBuqGSLwyhJk/mC2VPtDmk6+BBghFMLVKiV1gvRF5u/IMS5Jl5+kUtzRpqpb V1mgX94yGMRBcxxYMrKguOIIoxCy7+gEAmgSPjxoh+lDIRqoLLZPSGf+b77vXQvE/39B 6yPw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:user-agent:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date; bh=gEdxW+jEFqvaAaMJzkECvOotBm8Ww2iTWuDmYuHsnI4=; b=QYqORgG2mabTs/94HLuA17mUWQu2UqvNqa0H56klHZxMA1RAPNFs3wLiYq0NMlEuwI gSTbnJBs/PrgsFj/5124PNrPpwLtnt9mI3VlKXwgpljrrF9kQwK5L+kNO7MZCbS8W2yH wlh4yP4z+dPN+q3s7ORtbGIaV3N4n0iaG4Bb31B5w2qqF+1GXYLzI186T93s9lAgxLMb AEORH699zT77rM9kN+5WZct0WaVTxMzs3q2TOPYDpQJ1yidLDQtmNP4PTXU4BMv0d0jc PI9Li0KsxNZGWp0AfsqZ7Ff2LHNCXQcpZj9t8qzdZ5NNqvDdKmYiEoR8iv/afFL+F3wK 63Ug== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id hd42si743065ejc.727.2021.03.17.21.38.52; Wed, 17 Mar 2021 21:39:14 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229564AbhCREhT (ORCPT + 99 others); Thu, 18 Mar 2021 00:37:19 -0400 Received: from verein.lst.de ([213.95.11.211]:39854 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229454AbhCREg6 (ORCPT ); Thu, 18 Mar 2021 00:36:58 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 91B0768C4E; Thu, 18 Mar 2021 05:36:56 +0100 (CET) Date: Thu, 18 Mar 2021 05:36:56 +0100 From: Christoph Hellwig To: Ira Weiny Cc: Thomas Gleixner , Christoph Hellwig , linux-kernel@vger.kernel.org Subject: Re: kmap_local semantics Message-ID: <20210318043656.GA26988@lst.de> References: <20210312065413.GA29805@lst.de> <20210312153646.GE3014244@iweiny-DESK2.sc.intel.com> <878s6lzxsq.fsf@nanos.tec.linutronix.de> <20210318024418.GX3014244@iweiny-DESK2.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210318024418.GX3014244@iweiny-DESK2.sc.intel.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 17, 2021 at 07:44:20PM -0700, Ira Weiny wrote: > Agreed. I'm Sorry, I did not word the above clearly enough. Let me rephrase > that. > > Christoph, do you anticipate additional need to call kmap and hand the mappings > to other threads? If not then kmap_local is what you should use. If so, I'd > like to know why. No. Just looking into callers that want a mapping and then synchronously wait for I/O.