From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 26 Jun 2013 21:03:43 +0200 (CEST) Received: from multi.imgtec.com ([194.200.65.239]:56359 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S6827473Ab3FZTDmpYTka (ORCPT ); Wed, 26 Jun 2013 21:03:42 +0200 Message-ID: <51CB3B04.1070903@imgtec.com> Date: Wed, 26 Jun 2013 12:03:32 -0700 From: Leonid Yegoshin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Ralf Baechle CC: "Steven J. Hill" , "linux-mips@linux-mips.org" , Florian Fainelli Subject: Re: [PATCH v2] Revert "MIPS: make CAC_ADDR and UNCAC_ADDR account for PHYS_OFFSET" References: <1371742590-10138-1-git-send-email-Steven.Hill@imgtec.com> <20130626145234.GB7171@linux-mips.org> <20130626162302.GE7171@linux-mips.org> <20130626175015.GH7171@linux-mips.org> In-Reply-To: <20130626175015.GH7171@linux-mips.org> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.65.146] X-SEF-Processed: 7_3_0_01192__2013_06_26_20_03_36 Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 37149 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: Leonid.Yegoshin@imgtec.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips Ralf, On 06/26/2013 10:50 AM, Ralf Baechle wrote: > On Wed, Jun 26, 2013 at 04:50:03PM +0000, Leonid Yegoshin wrote: > >> EVA has actually INCREASE in user address space - I right now run system with 2GB phys memory and 3GB of user virtual memory address space. Work in progress is to verify that GLIBC accepts addresses above 2GB. > I took the 0x40000000 for a KSEG0-equivalent because you previously > mentioned the value of 0x80000000. I wrote about kernel address layout. With EVA a user address layout is a different beast. In EVA, user may have access, say [0x00000000 - 0xBFFFFFFF] through TLB and kernel may have access, say [0x00000000 - 0xDFFFFFFF] unmapped. But segment shifts are applied to each KSEG. > >> Yes, it is all about increasing phys and user memory and avoiding 64bits. Many solutions dont justify 64bit chip (chip space increase, performance degradation and increase in DMA addresses for devices). > Fair enough - but in the end the increasing size of metadata and pagetables > which has to reside in lowmem will become the next bottleneck and highmem > I/O performance has never been great, is on most kernel developers shit list > and performance optimizations for highmem are getting killed whenever they > are getting into the way. EVA doesn't use HIGHMEM. Kernel has a direct access to all memory in, say 3GB (3.5GB?). Malta model gives only 2GB because of PCI bridge loop problem. > > So I'd say EVA gives you something like 1.5GB of memory at most with good > performance and a 2GB userspace and something like 0.5GB, maybe 0.75GB > with a 3GB userspace. Beyond that you need highmem and that's where things, > especially kernel programming get more complicated and slower. Ralf, PTE and page table sizes depends from page size and HUGE page table implementation. With EVA the ratio of usable and service (PTE + page table) memory is the same as legacy MIPS and independs from used user space size. Right now I am running SOAK tests + additional "thrash" instance for 1500MB on 2GB physical Malta memory and see: ... Thrash v0.3 thrashing over 1500 megabytes ... vmstat procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 10 0 0 950480 252384 107856 0 0 1 18 166 132 75 25 0 0 See: swap si/so == 0. I use 16KB pages. > > Ralf - Leonid.