From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6CC3EC433EF for ; Fri, 5 Nov 2021 10:11:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B65E6127B for ; Fri, 5 Nov 2021 10:11:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233024AbhKEKOQ (ORCPT ); Fri, 5 Nov 2021 06:14:16 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:51784 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232907AbhKEKOP (ORCPT ); Fri, 5 Nov 2021 06:14:15 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 64C681FD48; Fri, 5 Nov 2021 10:11:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1636107095; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4ejDMGvgIuDocz2b0aa98zlaQD86AN/VRlLMkw+8Vec=; b=JR8Vz4hLNEh4CPaZ3xdW9l99gjCqQCx01yrLKQCHmfNxqr+3swjJuOrsHCsMKGiAHASK5n g0O8IS45WEHHGy2R/xhAbmQpZ1bsM9ESdLIuHPUCn0K0o0awp+Y63GiVYhfwP6nlQ0YpAk ngQzrYBgROglOwVxNpAWA8jCe//J58Q= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 3401513FBA; Fri, 5 Nov 2021 10:11:35 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id EtY2ClcDhWEafAAAMHmgww (envelope-from ); Fri, 05 Nov 2021 10:11:35 +0000 Subject: Re: [PATCH v4 4/4] btrfs: increase metadata alloc size to 5GB for volumes > 50GB To: Stefan Roesch , linux-btrfs@vger.kernel.org, kernel-team@fb.com References: <20211029183950.3613491-1-shr@fb.com> <20211029183950.3613491-5-shr@fb.com> From: Nikolay Borisov Message-ID: <443789f1-1b62-80e6-a88d-73e1fd11233b@suse.com> Date: Fri, 5 Nov 2021 12:11:34 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <20211029183950.3613491-5-shr@fb.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 29.10.21 г. 21:39, Stefan Roesch wrote: > This increases the metadata default allocation size from 1GB to 5GB for > volumes with a size greater than 50GB. Imo such a change would warrant more data about why it's ok. Clearly there is some internal facebook workload which benefits from this, however this doesn't automatically mean it will be beneficial for the wider user base. Also your cover letter doesn't contain any more specifics about the particular workload. Isn't 5g a bit too steep, perhaps 2 is larger and yet more conservative? > > Signed-off-by: Stefan Roesch > --- > fs/btrfs/space-info.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c > index 7370c152ce8a..44507262c515 100644 > --- a/fs/btrfs/space-info.c > +++ b/fs/btrfs/space-info.c > @@ -195,7 +195,7 @@ static u64 compute_chunk_size_regular(struct btrfs_fs_info *info, u64 flags) > > /* Handle BTRFS_BLOCK_GROUP_METADATA */ > if (info->fs_devices->total_rw_bytes > 50ULL * SZ_1G) > - return SZ_1G; > + return 5ULL * SZ_1G; > > return SZ_256M; > } >