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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id E747BC433FE for ; Fri, 4 Nov 2022 03:18:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3A8716B0071; Thu, 3 Nov 2022 23:18:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3304B6B0073; Thu, 3 Nov 2022 23:18:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1D1876B0074; Thu, 3 Nov 2022 23:18:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 097286B0071 for ; Thu, 3 Nov 2022 23:18:50 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id CE20C120543 for ; Fri, 4 Nov 2022 03:18:49 +0000 (UTC) X-FDA: 80094302778.22.DC0FDB6 Received: from mail-pj1-f46.google.com (mail-pj1-f46.google.com [209.85.216.46]) by imf23.hostedemail.com (Postfix) with ESMTP id 68E3F140003 for ; Fri, 4 Nov 2022 03:18:49 +0000 (UTC) Received: by mail-pj1-f46.google.com with SMTP id z5-20020a17090a8b8500b00210a3a2364fso6941648pjn.0 for ; Thu, 03 Nov 2022 20:18:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=dWJcYf1IEOyHa62fvZcRIIgfl8vj4Lo0xXBk4TWvE4o=; b=VAQ4tQAGDSL6HKHNbaB3NF54C7Fen8bOFiCbi4PtSBCoGKZWm4V6H4yctKFjJP/s1d gfVWsWEnhSSlFtEME+lXGCwrHPPE1AWyHJADTSUX3M6zkg9Om288/Yomi1m/3ojgrqzj YwfNbB4ArMv34TkvtfXd38RZZrhSUAVNVyRHc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=dWJcYf1IEOyHa62fvZcRIIgfl8vj4Lo0xXBk4TWvE4o=; b=cDJjnpayhjXgGhRy69VkvYJwee8zjdAm7cvzTNnWsuwkojS4UJ+i0e+OI7gbfF3zVn HWvlBZCHWfg7RxS81YdyINuy+5ABrnFOem3E3rFC+UOrNaS3j8yL4LIIjshfik6y7hQ+ Fa+7Vtri6R8p9agRd8mz0jtoLt2mlctTtSrXnS0t39bkimCrnO3Xpol4h0QxCASGawZm RpOSo6N6bb0pL6AXEJOBvaIExy56HI0p4Vujg8TUvU0ftOmiw8885Ey9RkIbbitDytqJ BUQzBOwDcfWdug4dQxyGQ6oTJsaDjB+S+a8tImBorK/DVkRYcemf1AkA4g1vXiGul8UH Xsxw== X-Gm-Message-State: ACrzQf14FpdlDGfgo576X4frww+IWAJ6u/ibAKqKw7K4D+31NEQaNALv kU+ntq9Wj2ELK3LkuqxL1yDnow== X-Google-Smtp-Source: AMsMyM6YDoe38XGmkuz7YEBbI47fSd/4+C8NqQ48pKnobyDDqnFPlIak2tfZkBrAKUX6W6O/HeBI6w== X-Received: by 2002:a17:902:a502:b0:186:aed2:f69d with SMTP id s2-20020a170902a50200b00186aed2f69dmr33699590plq.46.1667531928235; Thu, 03 Nov 2022 20:18:48 -0700 (PDT) Received: from google.com ([240f:75:7537:3187:f2f6:8f5:87c8:3aeb]) by smtp.gmail.com with ESMTPSA id y8-20020a1709027c8800b001785a72d285sm1437938pll.48.2022.11.03.20.18.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Nov 2022 20:18:47 -0700 (PDT) Date: Fri, 4 Nov 2022 12:18:43 +0900 From: Sergey Senozhatsky To: Minchan Kim Cc: Sergey Senozhatsky , Andrew Morton , Nitin Gupta , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCHv4 2/9] zram: Add recompression algorithm sysfs knob Message-ID: References: <20221018045533.2396670-1-senozhatsky@chromium.org> <20221018045533.2396670-3-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1667531929; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=dWJcYf1IEOyHa62fvZcRIIgfl8vj4Lo0xXBk4TWvE4o=; b=0CK/PNsW604AB1a03wbaZ4L8w6FU2ZjRBsA8WZ3ChkzFZ9LJW3/KuIIovcMg+YxLeqAyLf XPYhmHiXCtEmQpVdPuwOHygcjRLC95kgTZoG7bKtI5xvCFzTOWFcSk/BjhLRQqvu/jMh7G 5ZGMffttlCXeYL4IdA3RIvuLQHaqL6c= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=VAQ4tQAG; spf=pass (imf23.hostedemail.com: domain of senozhatsky@chromium.org designates 209.85.216.46 as permitted sender) smtp.mailfrom=senozhatsky@chromium.org; dmarc=pass (policy=none) header.from=chromium.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1667531929; a=rsa-sha256; cv=none; b=7uCVQQDTSEjAUW4VeM1tnD/0tyWtzlT8+h3xcXyZhsCHCecV+i6hFVxRuehviURNhoJld1 zVc9QTcTYhiGfIBNFgXO9wD71HLImSXRANypzuohtadlB3SouG2UBezdE2wQUfOXSIgCbz k9rCc0VISxOAYFJiBrj0wcoKVrujeVc= X-Stat-Signature: pascznadf6ozwcgp1q1z4xr7s4tu7t9o X-Rspamd-Queue-Id: 68E3F140003 X-Rspamd-Server: rspam06 X-Rspam-User: Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=VAQ4tQAG; spf=pass (imf23.hostedemail.com: domain of senozhatsky@chromium.org designates 209.85.216.46 as permitted sender) smtp.mailfrom=senozhatsky@chromium.org; dmarc=pass (policy=none) header.from=chromium.org X-HE-Tag: 1667531929-237224 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000084, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On (22/11/03 09:34), Minchan Kim wrote: > > > My point is that we don't need to implement it atm but makes the > > > interface to open the possibility for future extension. > > > > > > What do you think? > > > > So, as far as I understand, we don't have reason to add remove_recomp_algo > > right now. And existing recomp_algo does not enforce any particular format, > > it can be extended. Right now we accept "$name" but can do something like > > "$name:$priority". The only thing that we probably need to do is rename > > recomp_algo to either add_recomp_algo or register_recomp_algo? > > Yeah, I like the name and priority format. > > Only question is how we could support algorithm selection change > under considering multiple secondary algorithms. So what I was thinking about, and I'm still in the mental model that re-compression is a user-space event, just like writeback, extension of recompress sysfs knob with "algo_index" (or something similar) which will mirror algorithm priority. Example: Configure 2 alternative algos, with priority 1 and 2 echo "name=lz4 priority=1" > recomp_algo echo "name=lz5 priority=2" > recomp_algo Recompress pages using algo 1 and algo 2 echo "type=huge threshold=3000 algo_idx=1" > recompress echo "type=idle threshold=2000 algo_idx=2" > recompress Maybe we can even pass algo name instead of idx.