On Sun, Oct 4, 2015 at 9:59 PM, Richard Tresidder <rtresidd@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hi Steven > Nope standard x86_64 > kernel 3.10.0-229.14.1.el7.x86_64 Hmm. > > Was rather surprised as all my quick reading indicates that the kernel > should quite happily do this... > Though looks like its the largest chunk you can request? I'm not well enough > up to speed with the nitty gritty.. Yeah, 4MB is the upper limit IIRC. > > There is mention of something similar against this card on www linuxtv org > wiki index.php Hauppauge_WinTV-HVR-2200 > > ******** > Note: Some kernels will not have enough free memory available for the > driver. The dmesg error will start with a message like this: > ] modprobe: page allocation failure: order:10, mode:0x2000d0 > followed by a stack trace and other debugging information. While the driver > will load, no devices will be registered. > The simple workaround is to allocate more memory for the kernel: > sudo /bin/echo 16384 > /proc/sys/vm/min_free_kbytes > sudo rmmod saa7164 > sudo modprobe saa7164 > ******** Hmm. I wasn't aware people in the past has seen the issue either. I assume you've tried the above and its not helping, or in fact growing that number for experimentation purposes. Do you have a large number of other devices / drivers loaded? I suspect another driver is burning through kernel memory before the saa7164 has a chance to be initialized. I took a quick look at saa7164-fw.c this morning, I see no reason why the allocation is required at all. With a small patch the function could be made to memcpy from 'src' directly, dropping the need to allocate srcbuf what-so-ever. This would remove the need for the 4MB temporary allocation, and might get you past this issue, likely on to the next (user buffer allocations are also large - as I recall). Note that the 4MB allocation is temporary, so its not a long term saving, but it might get you past the hump. -- Steven Toth - Kernel Labs http://www.kernellabs.com -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
