From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1AE5D72 for ; Mon, 1 Nov 2021 02:35:03 +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=YVq1DQ33vlTfqQwlUVtldRtum7VTJ4Qf1wo2xOWYsbs=; b=gRMXvXUxYDh5PXfGY5PmoKkYNO XFLFQoynUl1o2KWv51EHkiPEdljCH01lPjc7+M/bKuM+7+9IMZ5jSaJ1MGCpifQEIS4Qcd4dJc1Wa 8dO9Kqrf/Di+5EBltPtFcL+YtbwV3OLvk6Xd+aK2ECFw7/Gdg6aHCwAbztH3lXoJa/BeCs6oUo293 PDjr1JQ8F7sTCQXgKQMS9nw7lOnA4+04vMjmHw0d21F6Bmw25BeerzvqDabqxyqC/dw8tJs3qOPJ5 esyiwcXYwn4sfB97InYFLCCmiTcpnwhbut8Sq53K97IVVQd9qJb66Xm71VeQJPsOdp6iE9VKRW5XR oQBeZ3uw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mhN6c-003SWk-T1; Mon, 01 Nov 2021 02:31:47 +0000 Date: Mon, 1 Nov 2021 02:31:26 +0000 From: Matthew Wilcox To: Pavel Begunkov Cc: Dave Chinner , "Darrick J. Wong" , Christoph Hellwig , Jane Chu , "dan.j.williams@intel.com" , "vishal.l.verma@intel.com" , "dave.jiang@intel.com" , "agk@redhat.com" , "snitzer@redhat.com" , "dm-devel@redhat.com" , "ira.weiny@intel.com" , "vgoyal@redhat.com" , "linux-fsdevel@vger.kernel.org" , "nvdimm@lists.linux.dev" , "linux-kernel@vger.kernel.org" , "linux-xfs@vger.kernel.org" Subject: Re: [dm-devel] [PATCH 0/6] dax poison recovery with RWF_RECOVERY_DATA flag Message-ID: References: <2102a2e6-c543-2557-28a2-8b0bdc470855@oracle.com> <20211028002451.GB2237511@magnolia> <20211028225955.GA449541@dread.disaster.area> <22255117-52de-4b2d-822e-b4bc50bbc52b@gmail.com> <20211029223233.GB449541@dread.disaster.area> <1a76314d-9b62-82a3-2787-96e6b83720fc@gmail.com> Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1a76314d-9b62-82a3-2787-96e6b83720fc@gmail.com> On Sun, Oct 31, 2021 at 01:19:48PM +0000, Pavel Begunkov wrote: > On 10/29/21 23:32, Dave Chinner wrote: > > Yup, you just described RWF_HIPRI! Seriously, Pavel, did you read > > past this? I'll quote what I said again, because I've already > > addressed this argument to point out how silly it is: > > And you almost got to the initial point in your penult paragraph. A > single if for a single flag is not an issue, what is the problem is > when there are dozens of them and the overhead for it is not isolated, > so the kernel has to jump through dozens of those. This argument can be used to reject *ANY* new feature. For example, by using your argument, we should have rejected the addition of IOCB_WAITQ because it penalises the vast majority of IOs which do not use it. But we didn't. Because we see that while it may not be of use to US today, it's a generally useful feature for Linux to support. You say yourself that this feature doesn't slow down your use case, so why are you spending so much time and energy annoying the people who actually want to use it? Seriously. Stop arguing about something you actually don't care about. You're just making Linux less fun to work on.