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 E88FF20328; Fri, 7 Jun 2024 18:16:23 +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=1717784184; cv=none; b=aMF9uuevRYRAyxMZXJV5P3D/qF9fapoh+dl3D51yu/yUzB9+be7oDAXPBGJEGdpBJHlvVJzHz9S/iZQp9acjyharyz9/KP4gHF74pY8pU02ykvpPFgrHohDKtjzkFunglh/ezBLP+IvYZWb4lUGnftVyVxsvoosjwAF0cD5uVCk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717784184; c=relaxed/simple; bh=JXZUAF1M4vQTr6VpW3B38YSyXXvILfMnD0BrpTGqeGs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BeOlQZlfb+sUAliJ5N8GyGlq9w/vn4mRbFzJJVqPnCyz1/yOGMLk8ONiRngQNnZaATet8u6FVxvDJJ2ENlbY7k8nElL4SaHinECbZd47m2GFDLaQMGAQhJcJgxHj8qA2vhDb+wyF+Ydck4Y9Ccg/5SGBW3A1NVlTax3BRzN9QLw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LvOkCDMo; 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="LvOkCDMo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8059AC2BBFC; Fri, 7 Jun 2024 18:16:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1717784183; bh=JXZUAF1M4vQTr6VpW3B38YSyXXvILfMnD0BrpTGqeGs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LvOkCDMoMpKx862D90b+AnbUfo7K3a1eCgDByvp9Bu8OfR24sCsy9bteluiU1FTMQ Ww1USi9P2Zu9deWwHAwgNqbofkW7P2/uLbGwrjIdv7pR2PWd5exFTljJKkI8dHYoV8 xfdNNxlAHQIFzW+aghpJUzSLLCxiUgn8dL3YfVRdRRGUIqiNA4oEmA7xd5fAgULAXx /0y7gm7xffOzDtO2aB+ihn8oIjdAEiJkfMplDZbZbvfYSvRWlmgcfg2uGqjcayiKt7 +8ppsqd4ZZIW477OFkyTW1DxDAdZQEiHHuoyVI/ZLLqERSXnYLP65gc1o9XqdfvwNT z+kGSiM9tJHJA== Date: Fri, 7 Jun 2024 11:16:22 -0700 From: "Darrick J. Wong" To: Christoph Hellwig Cc: zlang@redhat.com, fstests@vger.kernel.org, linux-xfs@vger.kernel.org, guan@eryu.me Subject: Re: [PATCHSET 3/3] xfsprogs: scale shards on ssds Message-ID: <20240607181622.GN53013@frogsfrogsfrogs> References: <171744525781.1532193.10780995744079593607.stgit@frogsfrogsfrogs> <20240605005636.GI52987@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 Thu, Jun 06, 2024 at 10:06:42PM -0700, Christoph Hellwig wrote: > On Tue, Jun 04, 2024 at 05:56:36PM -0700, Darrick J. Wong wrote: > > Not much other than the AG[IF] and log grant heads becoming less hot. > > That pushes the bottlenecks to the storage device, which indeed is about > > 8 per device. More if you can raid0 them. > > > > *Fortunately* for metadata workloads the logging code is decent about > > deduplicating repeated updates, so unless you're doing something truly > > nasty like synchronous direct writes to a directory tree with parent > > pointers that is being modified heavily, it takes some effort to > > overload the ssd. > > > > (Or a crappy ssd, I guess. Maybe I'll pull out the 860 QVO and see how > > it does.) > > Ok. I'm also a little worried about creating lots of AGs for tiny > file systems. Then again I've not actually been able to find the code > yet which I should probably look at first. It shouldn't create fewer AGs than what the default algorithm would have calculated, and it won't create AGs smaller than 4GB. --D