From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751556AbaANODa (ORCPT ); Tue, 14 Jan 2014 09:03:30 -0500 Received: from mx1.redhat.com ([209.132.183.28]:22807 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751451AbaANODZ (ORCPT ); Tue, 14 Jan 2014 09:03:25 -0500 Message-ID: <52D54375.8070706@redhat.com> Date: Tue, 14 Jan 2014 15:02:29 +0100 From: Jerome Marchand User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Sergey Senozhatsky CC: Minchan Kim , Nitin Gupta , linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] zram: rework reported to end-user zram statistics 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> <20140114135355.GC2226@swordfish.minsk.epam.com> In-Reply-To: <20140114135355.GC2226@swordfish.minsk.epam.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/14/2014 02:53 PM, Sergey Senozhatsky wrote: > 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? The READA thing was my only concern for 2/3, so yes for this one. Concerning the third patch, I'd like to see what other people think about which stats we want to report. > > -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 >> >>