From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751662AbaANN4t (ORCPT ); Tue, 14 Jan 2014 08:56:49 -0500 Received: from mail-ee0-f49.google.com ([74.125.83.49]:57546 "EHLO mail-ee0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751588AbaANN4r (ORCPT ); Tue, 14 Jan 2014 08:56:47 -0500 Date: Tue, 14 Jan 2014 16:53:55 +0300 From: Sergey Senozhatsky To: Jerome Marchand Cc: Minchan Kim , Nitin Gupta , linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] zram: rework reported to end-user zram statistics Message-ID: <20140114135355.GC2226@swordfish.minsk.epam.com> References: <1389692260-4421-1-git-send-email-sergey.senozhatsky@gmail.com> <1389692260-4421-4-git-send-email-sergey.senozhatsky@gmail.com> <52D513BD.7000800@redhat.com> <20140114111012.GC2180@swordfish.minsk.epam.com> <52D53F11.3090005@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52D53F11.3090005@redhat.com> User-Agent: Mutt/1.5.22 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (01/14/14 14:43), Jerome Marchand wrote: [..] > >> > >> That's weird: good/bad_compress are accounted, but it seems to me that > >> they are to never used in any way. If so, there is indeed no reason to > >> keep them. > >> > >> > >>> Account each sub-request > >>> compression size so we can calculate real device compression ratio. > >> > >> Your patch doesn't change the way pages_stored and compr[essed]_size > >> are accounted. What does your patch change that allow us to calculate > >> the "real" compression ratio? > >> > >>> > >>> 4) reported zram stats: > >>> - num_writes -- number of writes > >>> - num_reads -- number of reads > >>> - pages_stored -- number of pages currently stored > >>> - compressed_size -- compressed size of pages stored > >> > >> Wouldn't it be more practical to report the original and compressed > >> data sizes using the same units as it is currently done? > >> > > > > hm, do we really need pages_stored stats? what kind of unseful information it > > shows to end user?.. perhaps, it's better to replace it with accounted passed > > bvec->bv_len (as uncompressed_size). > > > > That's really going to complicates things. We would need to keep track > of which sectors of a particular page has been written to. It's much > easier to keep current page granularity and consider any partial I/O > as an whole page I/O. > fair enough. thank you. 2/3 and 3/3 were changed according to your comments: - 2/3 drop READA check - 3/3 update commit message. ready to re-publish. may I add your ACK to all 3 patches or just to 1/3? -ss > > > >> Jerome > >> > >>> - pages_zero -- number of zero filled pages > >>> - failed_read -- number of failed reads > >>> - failed_writes -- can happen when memory is too low > >>> - invalid_io -- non-page-aligned I/O requests > >>> - notify_free -- number of swap slot free notifications > >>> - memory_used -- zs pool zs_get_total_size_bytes() > >>> > >>> Signed-off-by: Sergey Senozhatsky > >