From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from nz-out-0102.google.com (nz-out-0102.google.com [64.233.162.202]) by ozlabs.org (Postfix) with ESMTP id 3549067BF0 for ; Fri, 12 May 2006 16:51:37 +1000 (EST) Received: by nz-out-0102.google.com with SMTP id x7so93680nzc for ; Thu, 11 May 2006 23:51:36 -0700 (PDT) Message-ID: <7cb1293c0605112351y658460a0x8b793ea12004dbfc@mail.gmail.com> Date: Thu, 11 May 2006 23:51:36 -0700 From: "Srinivas Murthy" To: linuxppc-dev Subject: 2.6 vs 2.4 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_19224_20163739.1147416696767" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , ------=_Part_19224_20163739.1147416696767 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Hi, Wolfgang Denk has a good listing of issues to consider betn linux 2.4 vs 2.6 for ppc82xx based platforms (http://www.denx.de/wiki/Know/Linux24vs26). Would this recommendation still hold? Are there any patches, developments in this area? Thanks, _Srinivas ------=_Part_19224_20163739.1147416696767 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline
Hi,
 Wolfgang Denk has a good listing of issues to consider betn linu= x 2.4 vs 2.6 for ppc82xx based platforms (http://www.denx.de/wiki/Know/Linux24vs26).
 
 Would this recommendation still hold?
 
 Are there any patches, developments in this area?
 
Thanks,
_Srinivas
 
------=_Part_19224_20163739.1147416696767-- From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 6AB7E679F3 for ; Fri, 12 May 2006 23:57:19 +1000 (EST) Subject: Re: 2.6 vs 2.4 From: Benjamin Herrenschmidt To: Srinivas Murthy In-Reply-To: <7cb1293c0605112351y658460a0x8b793ea12004dbfc@mail.gmail.com> References: <7cb1293c0605112351y658460a0x8b793ea12004dbfc@mail.gmail.com> Content-Type: text/plain Date: Fri, 12 May 2006 23:57:10 +1000 Message-Id: <1147442231.9412.9.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2006-05-11 at 23:51 -0700, Srinivas Murthy wrote: > Hi, > Wolfgang Denk has a good listing of issues to consider betn linux 2.4 > vs 2.6 for ppc82xx based platforms > (http://www.denx.de/wiki/Know/Linux24vs26). > > Would this recommendation still hold? > > Are there any patches, developments in this area? The main open question is: is somebody still maintaining the 8xx kernel port ? Ben. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 11F95679F7 for ; Sat, 13 May 2006 00:02:13 +1000 (EST) Subject: Re: 2.6 vs 2.4 From: Benjamin Herrenschmidt To: Srinivas Murthy In-Reply-To: <1147442231.9412.9.camel@localhost.localdomain> References: <7cb1293c0605112351y658460a0x8b793ea12004dbfc@mail.gmail.com> <1147442231.9412.9.camel@localhost.localdomain> Content-Type: text/plain Date: Sat, 13 May 2006 00:02:02 +1000 Message-Id: <1147442522.9412.12.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2006-05-12 at 23:57 +1000, Benjamin Herrenschmidt wrote: > On Thu, 2006-05-11 at 23:51 -0700, Srinivas Murthy wrote: > > Hi, > > Wolfgang Denk has a good listing of issues to consider betn linux 2.4 > > vs 2.6 for ppc82xx based platforms > > (http://www.denx.de/wiki/Know/Linux24vs26). > > > > Would this recommendation still hold? > > > > Are there any patches, developments in this area? > > The main open question is: is somebody still maintaining the 8xx kernel > port ? Oh , and to give a better reply after reading that web page... I'd say there might be a reason why 2.6 is slower (or appears slower) than 2.4 on some of those embedded platforms. It's definitely faster in a number of areas on 6xx and other desktop CPUs. A lot of embedded folks will then bitch and complain about the slowdown on their 8xx processor, but very few of them if not none popped up actually identifying the actual issues and coming up with solution for them during the 2.6 dev. cycle. Ben. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ug-out-1314.google.com (ug-out-1314.google.com [66.249.92.173]) by ozlabs.org (Postfix) with ESMTP id 88033679FF for ; Sat, 13 May 2006 00:36:45 +1000 (EST) Received: by ug-out-1314.google.com with SMTP id e2so359185ugf for ; Fri, 12 May 2006 07:36:43 -0700 (PDT) Message-ID: <82ecf08e0605120729l43041aebuaef375a568700354@mail.gmail.com> Date: Fri, 12 May 2006 11:29:37 -0300 From: "Thiago Galesi" To: "Srinivas Murthy" Subject: Re: 2.6 vs 2.4 In-Reply-To: <7cb1293c0605112351y658460a0x8b793ea12004dbfc@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed References: <7cb1293c0605112351y658460a0x8b793ea12004dbfc@mail.gmail.com> Cc: linuxppc-dev List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > Hi, > Wolfgang Denk has a good listing of issues to consider betn linux 2.4 vs > 2.6 for ppc82xx based platforms > (http://www.denx.de/wiki/Know/Linux24vs26). > > Would this recommendation still hold? Not much. This article is almost one year old. Even though some things do apply (like bigger footprint, etc), the kernel improved a lot on the months that followed that article. I've participated in a project that used a (somewhat patched) 2.6.10 kernel, with soccessful results. Not the mention the advantages of the 2.6 kernel in general. >The main open question is: is somebody still maintaining the 8xx kernel >port ? LINUX FOR POWERPC EMBEDDED PPC8XX P: Marcelo Tosatti S: Maintained (this has been determined AFAIK in OLS 2005) From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.multimedia-labs.de (mail.multimedia-labs.de [82.149.226.172]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mail.multimedia-labs.de", Issuer "Multimedia Labs CA" (not verified)) by ozlabs.org (Postfix) with ESMTP id A16CA67A3E for ; Sat, 13 May 2006 00:42:51 +1000 (EST) Received: from localhost (localhost [127.0.0.172]) by mail.multimedia-labs.de (Postfix) with ESMTP id 4C1841C80AF for ; Fri, 12 May 2006 16:42:48 +0200 (CEST) Received: from mail.multimedia-labs.de ([127.0.0.172]) by localhost (mail [127.0.0.172]) (amavisd-new, port 10024) with LMTP id 07286-03 for ; Fri, 12 May 2006 16:42:46 +0200 (CEST) Received: from xpc823.intern.randgruppe.info (e176171165.adsl.alicedsl.de [85.176.171.165]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.multimedia-labs.de (Postfix) with ESMTP id CA04F1C8083 for ; Fri, 12 May 2006 16:42:46 +0200 (CEST) Received: from [10.0.0.75] (unknown [10.0.0.75]) by xpc823.intern.randgruppe.info (Postfix) with ESMTP id 613B270A38 for ; Fri, 12 May 2006 16:43:53 +0200 (CEST) Message-ID: <44649F09.2020803@elitedvb.net> Date: Fri, 12 May 2006 16:43:21 +0200 From: Felix Domke MIME-Version: 1.0 To: linuxppc-dev Subject: Re: 2.6 vs 2.4 References: <7cb1293c0605112351y658460a0x8b793ea12004dbfc@mail.gmail.com> <82ecf08e0605120729l43041aebuaef375a568700354@mail.gmail.com> In-Reply-To: <82ecf08e0605120729l43041aebuaef375a568700354@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Thiago Galesi wrote: > Not much. This article is almost one year old. Even though some things > do apply (like bigger footprint, etc), the kernel improved a lot on > the months that followed that article. > I've participated in a project that used a (somewhat patched) 2.6.10 > kernel, with soccessful results. Can you point me to a list of changes which where done? I really like to check if they apply to my performance problems with 2.6 kernels, i.e. if it's worth porting the board specific changes to a newer kernel. Felix From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.multimedia-labs.de (mail.multimedia-labs.de [82.149.226.172]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mail.multimedia-labs.de", Issuer "Multimedia Labs CA" (not verified)) by ozlabs.org (Postfix) with ESMTP id 1C89E67A3F for ; Sat, 13 May 2006 00:55:00 +1000 (EST) Received: from localhost (localhost [127.0.0.172]) by mail.multimedia-labs.de (Postfix) with ESMTP id 5361F1C812E for ; Fri, 12 May 2006 16:22:49 +0200 (CEST) Received: from mail.multimedia-labs.de ([127.0.0.172]) by localhost (mail [127.0.0.172]) (amavisd-new, port 10024) with LMTP id 04386-01-2 for ; Fri, 12 May 2006 16:22:47 +0200 (CEST) Received: from xpc823.intern.randgruppe.info (e176171165.adsl.alicedsl.de [85.176.171.165]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.multimedia-labs.de (Postfix) with ESMTP id AAB5B1C80AF for ; Fri, 12 May 2006 16:22:47 +0200 (CEST) Received: from [10.0.0.75] (unknown [10.0.0.75]) by xpc823.intern.randgruppe.info (Postfix) with ESMTP id 1710270373 for ; Fri, 12 May 2006 16:23:54 +0200 (CEST) Message-ID: <44649A59.5050608@elitedvb.net> Date: Fri, 12 May 2006 16:23:21 +0200 From: Felix Domke MIME-Version: 1.0 To: linuxppc-dev Subject: Re: 2.6 vs 2.4 References: <7cb1293c0605112351y658460a0x8b793ea12004dbfc@mail.gmail.com> <1147442231.9412.9.camel@localhost.localdomain> In-Reply-To: <1147442231.9412.9.camel@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-1 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Benjamin Herrenschmidt wrote: >> Wolfgang Denk has a good listing of issues to consider betn linux 2.4 >>vs 2.6 for ppc82xx based platforms >>(http://www.denx.de/wiki/Know/Linux24vs26). >> Would this recommendation still hold? >> Are there any patches, developments in this area? > The main open question is: is somebody still maintaining the 8xx kernel > port ? The 4xx port has the same problem. When we switched from 2.4 to 2.6, IDE performance ("hdparm -t" to have a single number) was reduced by about 25% (even after trying to finetune the IDE driver - the time between the end of one transfer and the begin of the next transfer was just too long to saturate the harddisk). Because of my lack of knowledge of the block device layer's internals I wasn't able to track that down. My initial plan was to build a trace using the RiscTrace environment, to see any instruction executed between requests, but my company moved away from PPC4xx hardware (unfortunately), so I was never able to complete this. I still believe that other platforms have the same problems. On a 300MHz embedded mips machine, saturating a 100MBit network link via ftp is not easy. Our old 252MHZ PPC machines never performed better than around 5MB/s (but had a non-DMA NIC, which however could be satured in theory with about 70% cpu load, based on the bus bandwidth. Why are the remaining 30% not enough to do IDE DMA and the TCP overhead? Memory performance? But why did we had better numbers with 2.4 then?). On that mips machine, both IDE and network support DMA (agreed, it's a RTL8139, so it requires another memcpy), and memcpy() performance is >100MB/s. Where is the bottleneck? And, much more important: how do measure it? I'm sorry that I can't really much do anything else than complaining, but all my attempts to track down the problems were futile. I'm not sure if testing "ftp performance" (as a completely non-synthetic benchmark - FTP speed is/was a real issue on our platform) is "the right test", but it's one of the things where i personally want linux to become better. Or is this just a misconfiguration? Are there mysterious IO scheduler default parameters which are just suboptimal for our case? regards, Felix From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ug-out-1314.google.com (ug-out-1314.google.com [66.249.92.170]) by ozlabs.org (Postfix) with ESMTP id 45B3367A05 for ; Sat, 13 May 2006 02:24:34 +1000 (EST) Received: by ug-out-1314.google.com with SMTP id e2so375730ugf for ; Fri, 12 May 2006 09:24:33 -0700 (PDT) Message-ID: <82ecf08e0605120924p59ae4c21pb0fbf3e8b7170c07@mail.gmail.com> Date: Fri, 12 May 2006 13:24:33 -0300 From: "Thiago Galesi" To: "Felix Domke" Subject: 2.6 vs 2.4 In-Reply-To: <44649F09.2020803@elitedvb.net> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed References: <7cb1293c0605112351y658460a0x8b793ea12004dbfc@mail.gmail.com> <82ecf08e0605120729l43041aebuaef375a568700354@mail.gmail.com> <44649F09.2020803@elitedvb.net> Cc: linuxppc-dev List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > Can you point me to a list of changes which where done? I really like to > check if they apply to my performance problems with 2.6 kernels, i.e. if > it's worth porting the board specific changes to a newer kernel. > I'm sorry, I was thinking (specifically) of the 8XX port that went from broken to maintained. It would help if you could mention some ofthe problems you are having. >When we switched from 2.4 to 2.6, IDE performance ("hdparm -t" to have a >single number) was reduced by about 25% (even after trying to finetune >the IDE driver >On a 300MHz embedded mips machine, saturating a 100MBit network link via >ftp is not easy. Unfortunatelly my knowlege of IDE is almost 0. Maybe it has something to do with schedulers being used? About network, I had better results with a much slower processor than your reported 5Mb/s (60MHz PPC in 2.6.10) Thiago