Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752764AbaLTC0I (ORCPT ); Fri, 19 Dec 2014 21:26:08 -0500 Received: from mail-pa0-f45.google.com ([209.85.220.45]:65453 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752098AbaLTC0H (ORCPT ); Fri, 19 Dec 2014 21:26:07 -0500 Date: Sat, 20 Dec 2014 11:25:57 +0900 From: Minchan Kim To: Ganesh Mahendran Cc: Andrew Morton , Nitin Gupta , Linux-MM , linux-kernel Subject: Re: [PATCH v2] mm/zsmalloc: add statistics support Message-ID: <20141220022557.GA19822@blaptop> References: <1418993719-14291-1-git-send-email-opensource.ganesh@gmail.com> <20141219143244.1e5fabad8b6733204486f5bc@linux-foundation.org> <20141219233937.GA11975@blaptop> <20141219154548.3aa4cc02b3322f926aa4c1d6@linux-foundation.org> <20141219235852.GB11975@blaptop> <20141219160648.5cea8a6b0c764caa6100a585@linux-foundation.org> <20141220001043.GC11975@blaptop> <20141219161756.bcf7421acb4bc7a286c1afa3@linux-foundation.org> <20141220002303.GD11975@blaptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey Ganesh, On Sat, Dec 20, 2014 at 09:43:34AM +0800, Ganesh Mahendran wrote: > 2014-12-20 8:23 GMT+08:00 Minchan Kim : > > On Fri, Dec 19, 2014 at 04:17:56PM -0800, Andrew Morton wrote: > >> On Sat, 20 Dec 2014 09:10:43 +0900 Minchan Kim wrote: > >> > >> > > It involves rehashing a lengthy argument with Greg. > >> > > >> > Okay. Then, Ganesh, > >> > please add warn message about duplicaed name possibility althoug > >> > it's unlikely as it is. > >> > >> Oh, getting EEXIST is easy with this patch. Just create and destroy a > >> pool 2^32 times and the counter wraps ;) It's hardly a serious issue > >> for a debugging patch. > > > > I meant that I wanted to change from index to name passed from caller like this > > > > zram: > > zs_create_pool(GFP_NOIO | __GFP_HIGHMEM, zram->disk->first_minor); > > > > So, duplication should be rare. :) > > We still can not know whether the name is duplicated if we do not > change the debugfs API. > The API does not return the errno to us. > > How about just zsmalloc decides the name of the pool-id, like pool-x. > When the pool-id reaches > 0xffff.ffff, we print warn message about duplicated name, and stop > creating the debugfs entry > for the user. The idea is from the developer point of view to implement thing easy but my point is we should take care of user(ie, admin) rather than developer(ie, we). For user, /sys/kernel/debug/zsmalloc/zram0 would be more straightforward and even it doesn't need zram to export /sys/block/zram0/pool-id. Thanks. > > Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/