From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f173.google.com (mail-pd0-f173.google.com [209.85.192.173]) by kanga.kvack.org (Postfix) with ESMTP id 537E46B0032 for ; Mon, 22 Dec 2014 21:39:07 -0500 (EST) Received: by mail-pd0-f173.google.com with SMTP id ft15so6938153pdb.32 for ; Mon, 22 Dec 2014 18:39:07 -0800 (PST) Received: from lgeamrelo01.lge.com (lgeamrelo01.lge.com. [156.147.1.125]) by mx.google.com with ESMTP id oy3si6824959pdb.34.2014.12.22.18.39.04 for ; Mon, 22 Dec 2014 18:39:05 -0800 (PST) Date: Tue, 23 Dec 2014 11:40:45 +0900 From: Minchan Kim Subject: Re: [PATCH v2] mm/zsmalloc: add statistics support Message-ID: <20141223024045.GA30174@bbox> References: <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> <20141220022557.GA19822@blaptop> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Ganesh Mahendran Cc: Andrew Morton , Nitin Gupta , Linux-MM , linux-kernel , Seth Jennings , Dan Streetman Hi Ganesh, On Tue, Dec 23, 2014 at 10:26:12AM +0800, Ganesh Mahendran wrote: > Hello Minchan > > 2014-12-20 10:25 GMT+08:00 Minchan Kim : > > 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). > > Yes. I got it. > > > > > 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. > > BTW, If we add a new argument in zs_create_pool(). It seems we also need to > add argument in zs_zpool_create(). So, zpool/zswap/zbud will be > modified to support > the new API. > Is that acceptable? I think it's doable. The zpool_create_pool has already zswap_zpool_type. Ccing maintainers for double check. Many thanks. > > Thanks. > > > > > Thanks. > > > >> > >> 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 -- 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