From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f51.google.com (mail-pa0-f51.google.com [209.85.220.51]) by kanga.kvack.org (Postfix) with ESMTP id 50A9A82997 for ; Fri, 22 May 2015 09:14:58 -0400 (EDT) Received: by paza2 with SMTP id a2so10300893paz.3 for ; Fri, 22 May 2015 06:14:58 -0700 (PDT) Received: from mail-pd0-x22e.google.com (mail-pd0-x22e.google.com. [2607:f8b0:400e:c02::22e]) by mx.google.com with ESMTPS id gq8si3417389pbc.83.2015.05.22.06.14.57 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 22 May 2015 06:14:57 -0700 (PDT) Received: by pdbnk13 with SMTP id nk13so19464999pdb.1 for ; Fri, 22 May 2015 06:14:57 -0700 (PDT) Date: Fri, 22 May 2015 22:14:47 +0900 From: Minchan Kim Subject: Re: [PATCH] zram: check compressor name before setting it Message-ID: <20150522131447.GA14922@blaptop> References: <1432283515-2005-1-git-send-email-m.jabrzyk@samsung.com> <20150522085523.GA709@swordfish> <555EF30C.60108@samsung.com> <20150522124411.GA3793@swordfish> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150522124411.GA3793@swordfish> Sender: owner-linux-mm@kvack.org List-ID: To: Sergey Senozhatsky Cc: Marcin Jabrzyk , ngupta@vflare.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kyungmin.park@samsung.com Hello Sergey, On Fri, May 22, 2015 at 09:44:11PM +0900, Sergey Senozhatsky wrote: > On (05/22/15 11:12), Marcin Jabrzyk wrote: > > > > > >no. > > > > > >zram already complains about failed comp backend creation. > > >it's in dmesg (or syslog, etc.): > > > > > > "zram: Cannot initialise %s compressing backend" > > > > > OK, now I see that. Sorry for the noise. > > > > >second, there is not much value in exposing zcomp internals, > > >especially when the result is just another line in dmesg output. > > > > From the other hand, the only valid values that can be written are > > in 'comp_algorithm'. > > So when writing other one, returning -EINVAL seems to be reasonable. > > The user would get immediately information that he can't do that, > > now the information can be very deferred in time. > > it's not. > the error message appears in syslog right before we return -EINVAL > back to user. Although Marcin's description is rather misleading, I like the patch. Every admin doesn't watch dmesg output. Even people could change loglevel simply so KERN_INFO would be void in that case. Instant error propagation is more strighforward for user point of view rather than delaying with depending on another event. Thanks. > > -ss > > > I'm not for exposing more internals, but getting -EINVAL would be nice I -- Kind regards, Minchan Kim -- 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