From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Bryn M. Reeves" Subject: Re: [PATCH] dm-statistics: report precise timestamps and histogram Date: Wed, 19 Aug 2015 09:43:55 +0100 Message-ID: <20150819084354.GA7891@bmr.fab.redhat.com> References: Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Mikulas Patocka Cc: Mike Snitzer , Bryn Reeves , dm-devel@redhat.com, "Alasdair G. Kergon" List-Id: dm-devel.ids On Tue, Aug 18, 2015 at 04:26:16PM -0400, Mikulas Patocka wrote: > If the user selected precise timestamps or histogram, report it in the > output of the @stats_list message. > > If the user didn't select these options, no extra tokens are reported, > thus it is backward compatible with old software that doesn't know about > precise timestamps and histogram. It's not strictly backwards compatible in that someone mixing old and new code could have a situation where "old" dm-stats parsing code could see entries in list output created using "new" features. This would only affect users not implementing program_id filtering (or using it in broken ways) though so it's probably insignificant enough to be ignored. Regards, Bryn.