From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.marcansoft.com (marcansoft.com [212.63.210.85]) (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 402615C090 for ; Tue, 28 Nov 2023 15:02:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=marcan.st Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=marcan.st Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=marcan.st header.i=@marcan.st header.b="ogqIkfiD" Received: from [127.0.0.1] (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: marcan@marcan.st) by mail.marcansoft.com (Postfix) with ESMTPSA id 0671645F18; Tue, 28 Nov 2023 15:01:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=marcan.st; s=default; t=1701183720; bh=75+rL0teZ8g+m52S+qdkHz3Z4j+DntaIdyqECmrs7X0=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=ogqIkfiDct8lrw6p316x++V3cm5AyJHo/AJt2iSA2chDU2lC/fL9butVRBm4zPpGp eKeDcLk5I/8ghILKF0EBGCPzXEulht6wJ8DkupOsKg+SbDVIAs0q+dEuoeoOWxjtkR +Xud+2vwREeAGkfnFl8fceInM83bArIO7xbGSQtiQPIdXvdg1iXi5jbVFM/hfqVyNx rLxpHFcK4CSPAEUks5o2D8Qy0UgaMBWGftMvoA/wN3mxdkCqsNHy7N6PkndNlHg4ud msgWODB0/2uSHJrs1wxResix0aDHzBngBJpfxbe01aT35ZHCIx77NNN7Ur60aptE5C tg+vCUy7M9d3Q== Message-ID: Date: Wed, 29 Nov 2023 00:01:53 +0900 Precedence: bulk X-Mailing-List: asahi@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 0/1] Enforce 4k sectorize by default for mkfs Content-Language: en-US To: Josef Bacik , Neal Gompa Cc: Linux BTRFS Development , Anand Jain , Qu Wenruo , Qu Wenruo , David Sterba , Sven Peter , Davide Cavalca , Jens Axboe , Asahi Lina , Asahi Linux References: <20231116160235.2708131-1-neal@gompa.dev> <20231127160705.GC2366036@perftesting> From: Hector Martin In-Reply-To: <20231127160705.GC2366036@perftesting> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2023/11/28 1:07, Josef Bacik wrote: > On Thu, Nov 16, 2023 at 11:02:23AM -0500, Neal Gompa wrote: >> The Fedora Asahi SIG[0] is working on bringing up support for >> Apple Silicon Macintosh computers through the Fedora Asahi Remix[1]. >> >> Apple Silicon Macs are unusual in that they currently require 16k >> page sizes, which means that the current default for mkfs.btrfs(8) >> makes a filesystem that is unreadable on x86 PCs and most other ARM >> PCs. >> >> This is now even more of a problem within Apple Silicon Macs as it is now >> possible to nest 4K Fedora Linux VMs on 16K Fedora Asahi Remix machines to >> enable performant x86 emulation[2] and the host storage needs to be compatible >> for both environments. >> >> Thus, I'd like to see us finally make the switchover to 4k sectorsize >> for new filesystems by default, regardless of page size. >> >> The initial test run by Hector Martin[3] at request of Qu Wenruo >> looked promising[4], and we've been running with this behavior on >> Fedora Linux since Fedora Linux 36 (at around 6.2) with no issues. >> > > This is a good change and well documented. This isn't being ignored, it's just > a policy change that we have to be conservative about considering. We only in > the last 3 months have added a Apple Silicon machine to our testing > infrastructure (running Fedora Asahi fwiw) to make sure we're getting consistent > subpage-blocksize testing. Generally speaking it's been fine, we've fixed a few > things and haven't broken anything, but it's still comes with some risks when > compared to the default of using the pagesize. > > We will continue to discuss this amongst ourselves and figure out what we think > would be a reasonable timeframe to make this switch and let you know what we're > thinking ASAP. Thanks, Reminder that the Raspberry Pi 5 is also shipping with 16K pages by default now. The clock is ticking for an ever-growing stream of people upset that they can't mount/data-rescue/etc their rPi5 NAS disks from an x86 machine ;) - Hector