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=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 1471BC43457 for ; Mon, 12 Oct 2020 16:20:34 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A49862080A for ; Mon, 12 Oct 2020 16:20:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="tGTDtcIH"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="V7DSrccL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A49862080A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ox1DB/0qnk84gemsyx0+t3N4Nlv2ygwsiWc6P1V5ef0=; b=tGTDtcIHgDywM+pftkRohipvg 4R1Mx9fWDHY4T2BjD5garZiHP0aouRBdAhir2U3jEIxpFht124L7bLuyFILcRN6xPrDxg5OwVADub mv6vRl1rRCgEOsGOhx7DGWG5Bhs0r8z7dpWQn2KYV6VPVFsaqblmPpyRawGp4RzoYhbzEJkrcGDCO +ASnkFjb4pMDFPZ6r3j4r6QmgrMm/qW37TR1F5W+0Vo5LDoV1Wp+r1fpEkvsFouQX9gzZll/5mwGQ /8dolFMiJB2Kq3R5iRbJEQBWgz1N3Q2eD77Fm7Kd+NlFBXuQzQ3FYpCMZcFvQ54Wr4yk8eVVI2OLp 6/QxXd3+g==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kS0YJ-0000ly-1p; Mon, 12 Oct 2020 16:19:59 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kS0YA-0000hI-Kq; Mon, 12 Oct 2020 16:19:51 +0000 Received: from sol.localdomain (172-10-235-113.lightspeed.sntcca.sbcglobal.net [172.10.235.113]) (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 22B302080A; Mon, 12 Oct 2020 16:19:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602519589; bh=FXrMfe87r7In01hy1fZxNUDLVXbtP/5TJ3+XTzWq1o4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=V7DSrccLr5b4UIwMLihtwG0wHPpEpEeCdL4DEsryZDNbDbBe/031RRLLs/mkasjte GkozOXCGlriE75ewyNE/y/+1/YN0mvEXF3Fx+zkSk5bqABC19TCsH57zxXZt4yoDfc Gd/Q7Kn6Oc4wJMc886CZx9bFLur2svNEjPDcQyvk= Date: Mon, 12 Oct 2020 09:19:46 -0700 From: Eric Biggers To: Ira Weiny Subject: Re: [PATCH RFC PKS/PMEM 22/58] fs/f2fs: Utilize new kmap_thread() Message-ID: <20201012161946.GA858@sol.localdomain> References: <20201009195033.3208459-1-ira.weiny@intel.com> <20201009195033.3208459-23-ira.weiny@intel.com> <20201009213434.GA839@sol.localdomain> <20201010003954.GW20115@casper.infradead.org> <20201010013036.GD1122@sol.localdomain> <20201012065635.GB2046448@iweiny-DESK2.sc.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201012065635.GB2046448@iweiny-DESK2.sc.intel.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201012_121950_824029_FCC2A104 X-CRM114-Status: GOOD ( 15.78 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-aio@kvack.org, linux-efi@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, Peter Zijlstra , linux-mmc@vger.kernel.org, Dave Hansen , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, target-devel@vger.kernel.org, linux-mtd@lists.infradead.org, amd-gfx@lists.freedesktop.org, linux-kselftest@vger.kernel.org, Thomas Gleixner , drbd-dev@lists.linbit.com, devel@driverdev.osuosl.org, linux-cifs@vger.kernel.org, linux-nilfs@vger.kernel.org, linux-scsi@vger.kernel.org, linux-nvdimm@lists.01.org, linux-rdma@vger.kernel.org, x86@kernel.org, Matthew Wilcox , linux-afs@lists.infradead.org, cluster-devel@redhat.com, Ingo Molnar , intel-wired-lan@lists.osuosl.org, kexec@lists.infradead.org, xen-devel@lists.xenproject.org, linux-ext4@vger.kernel.org, bpf@vger.kernel.org, Dan Williams , Fenghua Yu , intel-gfx@lists.freedesktop.org, ecryptfs@vger.kernel.org, linux-um@lists.infradead.org, reiserfs-devel@vger.kernel.org, linux-block@vger.kernel.org, linux-bcache@vger.kernel.org, Borislav Petkov , Andy Lutomirski , Jaegeuk Kim , ceph-devel@vger.kernel.org, io-uring@vger.kernel.org, linux-cachefs@redhat.com, linux-nfs@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net, netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, Andrew Morton , linux-erofs@lists.ozlabs.org, linux-btrfs@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On Sun, Oct 11, 2020 at 11:56:35PM -0700, Ira Weiny wrote: > > > > And I still don't really understand. After this patchset, there is still code > > nearly identical to the above (doing a temporary mapping just for a memcpy) that > > would still be using kmap_atomic(). > > I don't understand. You mean there would be other call sites calling: > > kmap_atomic() > memcpy() > kunmap_atomic() Yes, there are tons of places that do this. Try 'git grep -A6 kmap_atomic' and look for memcpy(). Hence why I'm asking what will be the "recommended" way to do this... kunmap_thread() or kmap_atomic()? > And since I don't know the call site details if there are kmap_thread() calls > which are better off as kmap_atomic() calls I think it is worth converting > them. But I made the assumption that kmap users would already be calling > kmap_atomic() if they could (because it is more efficient). Not necessarily. In cases where either one is correct, people might not have put much thought into which of kmap() and kmap_atomic() they are using. - Eric ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/