From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out.tiscali.be (spoolo2.tiscali.be [62.235.13.211]) by dsl2.external.hp.com (Postfix) with ESMTP id 7B14F4A4A for ; Sun, 12 Oct 2003 07:28:18 -0600 (MDT) Message-ID: <3F8956EF.8050403@tiscali.be> Date: Sun, 12 Oct 2003 13:28:15 +0000 From: Joel Soete MIME-Version: 1.0 To: Grant Grundler Cc: Carlos O'Donell , "M. Grabert" , parisc-linux@lists.parisc-linux.org Subject: Re: [parisc-linux] traps.c 2.4 alignement [was: 2.6.0-test6-pa6 on b2k finaly crash] References: <3F5CB6FB0000CBFC@ocpmta1.freegates.net> <3F803388.5090304@tiscali.be> <3F804FC9.9040401@tiscali.be> <20031006172856.GB19370@dsl2.external.hp.com> In-Reply-To: <20031006172856.GB19370@dsl2.external.hp.com> Content-Type: text/plain; charset=us-ascii; format=flowed Sender: parisc-linux-admin@lists.parisc-linux.org Errors-To: parisc-linux-admin@lists.parisc-linux.org List-Help: List-Post: List-Subscribe: , List-Id: parisc-linux developers list List-Unsubscribe: , List-Archive: Hi Grant, Grant Grundler wrote: > On Sun, Oct 05, 2003 at 05:07:21PM +0000, Joel Soete wrote: > >>hmm don't think if it's related but just in case: >>I was just copying my kernel tree with 'tar cslpf - >>linux-2.6.0-test6-pa6 | ( cd Work ; tar xslpf -)' when >> >>Kernel panic: drivers/parisc/ccio-dma.c: ccio_alloc_range() I/O M. > > > You ran out of mapping resources. > panic(__FILE__ ": %s() I/O MMU is out of mapping resources.\n", > __FUNCTION__); > > >>I just retry same operation on the same system with same kernel but >>doesn't occurs a second time? > > > Not surprising. The bitmap search will fail if everything gets > mapped "sparsely" or we try to search for a large mapping (>32K, ie more > than 8 pages) but can't find it. If this is repeatible problem, change > > /* Ratio of Host MEM to IOV Space size */ > static unsigned long ccio_mem_ratio = 4; > > in drivers/parisc/ccio-dma.c (2.6 kernel) to 2. > Well the pb re-occurs but, as mentioned previously, it is difficult to reproduce the exact circumstance of this occurence? So test this change of ccio_mem_ratio = 4 to 2 and seems to works better :) > One patch would be welcome here: figure out a threshold when > allocations for single pages should share an 8-page "chunk" > (effectively one TLB entry). E.g. differentiate between LAN > and SCSI requests. LAN typically wants 1 entry (1500 byte MTU) > unless someone starts testing "Large Send" and is very "linear" > in it's DMA behavior (one DMA stream at a time). SCSI typically > wants 64k/128k (16 or 32 entries), has lots of those, and any one > of those could be the "next" DMA stream. ie thrashing the IO TLB > is much more likely with SCSI than LAN and we should allocate > entries differently based on that. > > The patch might be something like: > if ((pci_dev->class & MASK) == PCI_BASE_CLASS_NETWORK) { > ... > > in the right places to use a different (and new?) search loop. > Will try to understand and see what can i do. Thanks again, Joel