From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qa0-f53.google.com (mail-qa0-f53.google.com [209.85.216.53]) by kanga.kvack.org (Postfix) with ESMTP id 021046B0032 for ; Mon, 12 Jan 2015 15:07:16 -0500 (EST) Received: by mail-qa0-f53.google.com with SMTP id n4so9272463qaq.12 for ; Mon, 12 Jan 2015 12:07:15 -0800 (PST) Received: from smtp.variantweb.net (smtp.variantweb.net. [104.131.104.118]) by mx.google.com with ESMTPS id hj6si23874226qcb.49.2015.01.12.12.07.14 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 12 Jan 2015 12:07:14 -0800 (PST) Date: Mon, 12 Jan 2015 14:07:11 -0600 From: Seth Jennings Subject: Re: [PATCH v2] mm/zsmalloc: add statistics support Message-ID: <20150112200711.GA17340@cerebellum.variantweb.net> References: <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> <20141223024045.GA30174@bbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141223024045.GA30174@bbox> Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Ganesh Mahendran , Andrew Morton , Nitin Gupta , Linux-MM , linux-kernel , Dan Streetman On Tue, Dec 23, 2014 at 11:40:45AM +0900, Minchan Kim wrote: > 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. Late response, but fine by me. Seth > > 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 -- 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