From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:48755 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750732AbeDSHMj (ORCPT ); Thu, 19 Apr 2018 03:12:39 -0400 Subject: Re: nvme+btrfs+compression sensibility and benchmark To: Chris Murphy , Btrfs BTRFS References: <271cf4a5-92d6-04eb-5f7a-471c2997ca48@swiftspirit.co.za> From: Nikolay Borisov Message-ID: <8afc6157-29cf-00f1-460d-318ad655e3ad@suse.com> Date: Thu, 19 Apr 2018 10:12:36 +0300 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 18.04.2018 22:24, Chris Murphy wrote: > On Wed, Apr 18, 2018 at 10:38 AM, Austin S. Hemmelgarn > wrote: > >> For reference, the zstd compression in BTRFS uses level 3 by default (as >> does zlib compression IIRC), though I'm not sure about lzop (I think it >> uses the lowest compression setting). >> > > > The user space tool, zstd, does default to 3, according to its man page. > > -# # compression level [1-19] (default: 3) > > > However, the kernel is claiming it's level 0, which doesn't exist in the > man page. So I have no idea what we're using. This is what I get with mount > option compress=zstd > Currently the kernel-mode zstd compression doesn't really support any levels (compress_level is not set, even if it's passed, and even then zstd_set_level is also unimplemented). So this number doesn't really make any difference. > [ 4.097858] BTRFS info (device nvme0n1p9): use zstd compression, level 0 > > > > -- > Chris Murphy > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >