G'day Anish, I don't think you should conflate the shutdown issue with slower than claimed microSD cards. The shutdown issue may be a symptom, combining Fedora's assumptions about how quickly the kernel will finish writing data, with the microSD cards being much slower than the hard disks the halt script was written for.
Your fix of adding delay was based on the assumption that more time was needed for processes to be killed. I disagree. I think the delay was reducing the probability of dirty blocks in the cache, and you would have observed an improvement because of that alone. Your fix of adding a sync before umount might work. I'm interested to know how successful that is. Another thing you could do is reduce the retry timers and counters in __umount_loop so that it abandons the wait sooner, resulting in the laptop powering down with the filesystem still mounted. A better scenario than staying powered. __umount_loop tries an umount. In your photograph [12] that first umount failed with "umount: /home: device is busy." __umount_loop then counts the number of filesystems yet to be unmounted, allowing two seconds to elapse before it sends another signal to each process that has references to the filesystem. It then sleeps for three seconds before retrying up to 3 times. __umount_loop is then abandoned. That means the hang should not exceed 15 seconds. Is this what you find? If not, then this casts doubt on your solution. The "umount2: Device or resource busy" is interesting. I don't see this if I try to umount a device that is busy on Fedora 14. It may suggest that the umount is failing for a reason other than filesystems with remaining references or dirty blocks. I really doubt that fixing the microSD card write performance will properly fix this hang problem. Fixing the microSD card write performance, if it is below a specification, should be done anyway. It may well reduce the frequency of the hang. But as far as I can see, it isn't the only contributor to the hang. You seem to have settled on a myth. You seem to believe, based on selected evidence, that the problem is entirely to do with microSD cards. You continue to seek such evidence, but I think you should seek other evidence. -- James Cameron http://quozl.linux.org.au/ _______________________________________________ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
