From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 16E1835C1AD for ; Tue, 3 Feb 2026 05:17:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770095863; cv=none; b=fTOSUjGC3Fz2sllC14qVmdSDGFvr+aDaUvxGhImUmVNGBVBJLgq2F94yV/4g7KUAcyTyDn811FuhjCggi7f6WOZWnHdMc36PJqfGV7QdfXL6b6oAJ4GZ1ZlN5GQ+d0wXR4mRpNYnO3v+wPrz9MrI6+IbPl6F4CdgIvIVbcgAE+g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770095863; c=relaxed/simple; bh=DyYrPDsD8L2OWl/cA3lK4PLa+B0eTiKtVjv3MFdkUv4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XM/QYCeX/75526Y6seCP9Ie7gdvfzattE8SWS6UQpzAG0xlw//yDppg1LS61CIh/XP/5p6/JLcZoHy8B5R3dcBX7jKf53R4bDpIlCBULKp1RS7WvCNE6yo4jykad/ifIombLunqAxsgUVz9vLzZi0wQASvDFEb9Yf0bgCd/lCik= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=mCKDnNuI; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="mCKDnNuI" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=pYFzqoC20lLFGw0vJqhKGVBPHluXrteT63y94PqfWwI=; b=mCKDnNuIDsGtl3guYvvKcsVNZR rQSxn//zOWhPQ0DxVowiHGzWrmHhAf9K0EQ6R/P+VmNgjlGdu5LCW4bwbcNOXCp2SnOh7svLUOGOH PyWuak7+KZLqMN6vxWtg7jJm1NLlPX0uhU/onD4Qk5yvBRjfM97AisTO+KyTfQvuLFl0T66/Olkek bTBCi6uC/PvjOLjF+yM446K7qLmHjYTjMQahCoxF0jZ/FiGXC9ulE6ROo6IubF/E40/TXl/yrKnQE LB1aWk3M4b5xZy/Wr07zO9DXgdBuRbnw4kyRgCngmkd6+hnn6Nvdd8AdV/RaR6+wAwP1kBIF7JRQn 5a+YZ4gQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vn8n5-000000065Vm-115w; Tue, 03 Feb 2026 05:17:31 +0000 Date: Mon, 2 Feb 2026 21:17:31 -0800 From: Christoph Hellwig To: "Darrick J. Wong" Cc: Lukas Herbolt , Christoph Hellwig , linux-xfs@vger.kernel.org, cem@kernel.org Subject: Re: [PATCH] xfs: Use xarray to track SB UUIDs instead of plain array. Message-ID: 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: <20260202185013.GH7712@frogsfrogsfrogs> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html 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.