From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roger Heflin Subject: Re: What determines which interrupts are shared under Linux? Date: Tue, 15 Aug 2006 10:24:09 -0500 Message-ID: <44E1E719.6020005@atipa.com> References: <44E1D760.6070600@atipa.com> <1155654379.24077.286.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from 125.14.cm.sunflower.com ([24.124.14.125]:54678 "EHLO mail.atipa.com") by vger.kernel.org with ESMTP id S1030344AbWHOPYL (ORCPT ); Tue, 15 Aug 2006 11:24:11 -0400 In-Reply-To: <1155654379.24077.286.camel@localhost.localdomain> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: Linux-Kernel , linux-ide@vger.kernel.org Alan Cox wrote: > Ar Maw, 2006-08-15 am 09:17 -0500, ysgrifennodd Roger Heflin: >> On Linux when interrupts are defined similar to below, what defines say >> ide2, ide3 to be on the same interrupt? The bios, linux, the driver using >> the interrupt? And can that be controlled/overrode at the >> kernel/driver level? > > Only with a soldering iron. They are the way the system is wired. Moving > boards between slots may change the IRQ allocation. > >> I have identified that the disks that are shared on ide2, ide3 do funny >> things when both are being heavily used (dma_expiry), this is an older >> driver versions > > That could be occuring just through lack of PCI bus bandwidth. > > > Right now, all controllers are part of the NVIDIA chipset which should mean the are on the same PCI bandwidth. The block diagram does indicate the 4 sata channels as one unit, though I don't know exactly how things were internally done, performance testing seems to indicate that all 3 I am using are independent hardware as they don't seem to affect each others load. I am currently retesting under 2.6.17.8 to see if I have similar issues there, under that it show interrupts like below, different interrupt numbers, but similar sharing as ata1/ata2, and ata3/ata4 are on the same interrupt. ata1: SATA max UDMA/133 cmd 0xEC00 ctl 0xE802 bmdma 0xDC00 irq 16 ata2: SATA max UDMA/133 cmd 0xE400 ctl 0xE002 bmdma 0xDC08 irq 16 ata1: SATA link up 3.0 Gbps (SStatus 123) ata1: dev 0 cfg 49:2f00 82:706b 83:7e61 84:4023 85:7069 86:3e41 87:4023 88:407f ata1: dev 0 ATA-7, max UDMA/133, 321672960 sectors: LBA48 ata1: dev 0 configured for UDMA/133 ata2: SATA link up 3.0 Gbps (SStatus 123) ata2: dev 0 cfg 49:2f00 82:706b 83:7e61 84:4023 85:7069 86:3e41 87:4023 88:407f ata2: dev 0 ATA-7, max UDMA/133, 321672960 sectors: LBA48 ata2: dev 0 configured for UDMA/133 ata3: SATA max UDMA/133 cmd 0xD800 ctl 0xD402 bmdma 0xC800 irq 17 ata4: SATA max UDMA/133 cmd 0xD000 ctl 0xCC02 bmdma 0xC808 irq 17 ata3: SATA link up 3.0 Gbps (SStatus 123) ata3: dev 0 cfg 49:2f00 82:706b 83:7e61 84:4023 85:7069 86:3e41 87:4023 88:407f ata3: dev 0 ATA-7, max UDMA/133, 321672960 sectors: LBA48 ata3: dev 0 configured for UDMA/133 ata4: SATA link down (SStatus 0) Roger