Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751743AbdHYFG3 (ORCPT ); Fri, 25 Aug 2017 01:06:29 -0400 Received: from mail-pg0-f66.google.com ([74.125.83.66]:34242 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751411AbdHYFG2 (ORCPT ); Fri, 25 Aug 2017 01:06:28 -0400 Date: Fri, 25 Aug 2017 14:06:44 +0900 From: Sergey Senozhatsky To: Minchan Kim Cc: Sergey Senozhatsky , Sergey Senozhatsky , Andrew Morton , linux-kernel@vger.kernel.org, Nick Terrell Subject: Re: [PATCH] zram: add zstd to the supported algorithms list Message-ID: <20170825050644.GB5876@jagdpanzerIV.localdomain> References: <20170824014936.4738-1-sergey.senozhatsky@gmail.com> <20170824043038.GA13922@bgram> <20170824140440.GA5535@tigerII.localdomain> <20170825045036.GA26819@blaptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170825045036.GA26819@blaptop> User-Agent: Mutt/1.8.3 (2017-05-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1210 Lines: 36 On (08/25/17 13:50), Minchan Kim wrote: [..] > Thanks for the testing. > Could you resend the patch with this test result with my acked-by? ok. > Acked-by: Minchan Kim thanks. > Off-topic: > > In all ways, zstd beats deflate. Nick, Right? > > With zstd, I doubt we should show "deflate" to user. Many options just > make user confused. > The inflate have been there for representing high comp ratio but slower > speed. However, zstd is better unconditionally compared to deflate > so how about replacing deflate with zstd? > > Sergey, what do you think about it? hmmm... frankly, I don't think it would confuse anyone. the code is there - compiled - anyway, and the module is visible in /proc/crypto etc. if we will make it unavailable in zram then this can be confusing, probably... if anyone ever pays any attention at all. my guess is that people look what's in /sys/block/zram0/comp_algorithm just once, then they set up a create-zram script/systemd unit file/etc. and forget about it. cryto API is just a wrapper and it calls lib/comp_foo to do the actual work, and that lib/comp_foo *may be* can be implemented as a H/W (not S/W) compressing backend. well, who knows. -ss