From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8214836C0A6 for ; Tue, 3 Feb 2026 07:23:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770103391; cv=none; b=FrYvA3wub+cQ45AO9sF0UupiNKXNlKW5+aK2me8PKPl3sF0qw/EgIe+oIIKM07KzUQEVIpGhel+2GqCqR98z+umAWGUHdneiyKQdUSCkjYnfBwlxJdfBOlnjEYDQ2DqzeS2gyQsoFNUGmvNadFs0rgfdDxdoKW4xian6S+TQs7E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770103391; c=relaxed/simple; bh=tUWU2sVrEhBhYlltIsXA97vRDKXK1l2wD3LkE0IUOxc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eWo5345JxVG0DWakIi9jhk8fuBQm4npnaeCm2CFyDLwDAwwAvH+d53SENSyBvQ6hw9nZ7yYQcTPPvuXAD7EbMRPyNDWFudVGmJHXvxqsaOtcfy0CYf+B0LHU+c9gihClR6JK5uDtofYlxDK37+3KuZWGgyYUlIn4ZDSGKC9oLyk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LOzDZ3Kh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LOzDZ3Kh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 07F02C116D0; Tue, 3 Feb 2026 07:23:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770103391; bh=tUWU2sVrEhBhYlltIsXA97vRDKXK1l2wD3LkE0IUOxc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LOzDZ3KhJ0RUad74TMVfIV6anfJwfEeee2pUU6ftR3HnAHt8JAV25TfPXcXsBldad LE+uHRlc0Gyv6w7PUJTRC2CXVrhhVKf4wA/VRWZT+R7792ltazYR/sN7QWqtukHK+B Yqpacln2CFVGAMvKcWtiXo6mi3eDgss/3sm83orQxLI3Bs1zzn2hEOvFF12uuCMY8/ iAZzZ7e8Unb+bCzNsvPczw7IMP/EKa6m4Li71hPtVQ4xMPB+7K88YviiGS2RlMeJ1e WXGPnCsr8uAYXAS2wKkj5GvY4Qh8BAVOMXX8n58OJg+wOQ1AXZx//R8QMCc9A1jL9a rCwYObVful//A== Date: Mon, 2 Feb 2026 23:23:10 -0800 From: "Darrick J. Wong" To: Christoph Hellwig Cc: Lukas Herbolt , linux-xfs@vger.kernel.org, cem@kernel.org Subject: Re: [PATCH] xfs: Use xarray to track SB UUIDs instead of plain array. Message-ID: <20260203072310.GC1535390@frogsfrogsfrogs> References: <20260130154206.1368034-2-lukas@herbolt.com> <20260130154206.1368034-4-lukas@herbolt.com> <20260130165534.GG7712@frogsfrogsfrogs> <698e4433ee0b01978deed124792c7e57@herbolt.com> <20260202185013.GH7712@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Feb 02, 2026 at 09:17:31PM -0800, Christoph Hellwig wrote: > On Mon, Feb 02, 2026 at 10:50:13AM -0800, Darrick J. Wong wrote: > > > I do not have strong preference here. > > > > Since the original message said "krealloc prints out warning if > > allocation is bigger than 2x PAGE_SIZE", I figured that meant you were > > trying to mount more than (2 * 4096) / 16 == 512 different xfs > > filesystems on the same host. > > I don't remember any such message. But array or xarray iterations > should still scale well enough for a single mount time operation into > the 10.000nds of entries. > > > I don't have a particular problem with the array search and large memory > > allocation since I never mount that many filesystems, but you would > > appear to be the first user to complain about a scaling limit there... > > I was really just concerned about a single large allocation. But yeah, > it's not that large... That beind said I think the xarray version will > also look nicer than the original one. It's better than the raw kvalloc'd blob we have now :) --D