From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f70.google.com (mail-it0-f70.google.com [209.85.214.70]) by kanga.kvack.org (Postfix) with ESMTP id D99986B02FC for ; Tue, 28 Nov 2017 06:35:52 -0500 (EST) Received: by mail-it0-f70.google.com with SMTP id k186so281777ith.1 for ; Tue, 28 Nov 2017 03:35:52 -0800 (PST) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id 82sor2725272ite.139.2017.11.28.03.35.51 for (Google Transport Security); Tue, 28 Nov 2017 03:35:52 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20171120154648.6c2f96804c4c1668bd8d572a@linux-foundation.org> References: <20171018104832epcms5p1b2232e2236258de3d03d1344dde9fce0@epcms5p1> <20171120154648.6c2f96804c4c1668bd8d572a@linux-foundation.org> From: Dan Streetman Date: Tue, 28 Nov 2017 06:35:10 -0500 Message-ID: Subject: Re: [PATCH] zswap: Same-filled pages handling Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Srividya Desireddy , "sjenning@redhat.com" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "penberg@kernel.org" , Dinakar Reddy Pathireddy , SHARAN ALLUR , RAJIB BASU , JUHUN KIM , "srividya.desireddy@gmail.com" On Mon, Nov 20, 2017 at 6:46 PM, Andrew Morton wrote: > > On Wed, 18 Oct 2017 10:48:32 +0000 Srividya Desireddy wrote: > > > +/* Enable/disable handling same-value filled pages (enabled by default) */ > > +static bool zswap_same_filled_pages_enabled = true; > > +module_param_named(same_filled_pages_enabled, zswap_same_filled_pages_enabled, > > + bool, 0644); > > Do we actually need this? Being able to disable the new feature shows > a certain lack of confidence ;) I guess we can remove it later as that > confidence grows. No, it's not absolutely needed to have the param to enable/disable the feature, but my concern is around how many pages actually benefit from this, since it adds some overhead to check every page - the usefulness of the feature depends entirely on the system workload. So having a way to disable it is helpful, for use cases that know it won't benefit them. > > Please send a patch to document this parameter in > Documentation/vm/zswap.txt. And if you have time, please check that > the rest of that file is up-to-date? Srividya, can you send a patch to doc this feature please. I'll check the rest of the file is correct. > > Thanks. > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org