| From: D. Hugh Redelmeier <[EMAIL PROTECTED]> | Date: Mon, 28 Mar 2005 20:26:58 -0500 (EST)
| Summary: "modprobe ivtv" produces scarry messages and did not work. See <http://sourceforge.net/mailarchive/message.php?msg_id=11308676> I applied current Fedora Core 3 updates, including a kernel update, rebuilt ivtv-0.3.2p, installed it, and modprobed it. This time it worked. In particular, the following error did not show up in dmesg output: | Mar 28 18:05:36 redclaw kernel: ivtv: Allocate DMA stream 1 | Mar 28 18:05:36 redclaw kernel: modprobe: page allocation failure. order:5, mode:0xd0 I suspect that the key difference is that this time I did the modprobe in a freshly booted system and that the previous time the system had been running for a while. Running for a while could have caused physical memory had become fragmented. Here are subequent allocation messages from the modprobe that worked: ivtv: Registered v4l2 device, streamtype 2 minor 224 ivtv: Create stream 2 using 40 52224 byte buffers 0 kbytes total ivtv: Allocate stream 2 using 40 52224 byte buffers 2097152 kbytes total ivtv: Registered v4l2 device, streamtype 3 minor 24 ivtv: Create DMA stream 3 using 455 4608 byte buffers 0 kbytes total ivtv: Allocate DMA stream 3 using 455 4608 byte buffers 2097152 kbytes total ivtv: Registered v4l2 device, streamtype 4 minor 64 ivtv: Create stream 4 ivtv: Allocate stream 4 Here's what leaves me unsettled. The failure was apparently for allocating the scatter-gather array for stream 1. A scatter-gather array should be small: about 12 bytes per page in the stream. Yet the failed allocation was of order 5 -- 32 pages. That isn't a lot, so it shouldn't be hard to find that much contiguous space. On the other hand, that suggests that a *lot* of pages are going to be allocated to the stream: 32*4096 / 12 = 10922 40 megabytes of RAM. Something seems wrong. Finally, I would point out that the driver did not fail gracefully. If allocation fails, the driver should shut down cleanly, but it did not. So there are a bunch of dangling ends with respect to my original report. BTW, I got a private message from someone who had a similar problem. I asked them to post to the list, but I don't think that they did. That was the only response I've gotten. ------------------------------------------------------- This SF.Net email is sponsored by: New Crystal Reports XI. Version 11 adds new functionality designed to reduce time involved in creating, integrating, and deploying reporting solutions. Free runtime info, new features, or free trial, at: http://www.businessobjects.com/devxi/728 _______________________________________________ ivtv-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ivtv-devel
