On Thu, 2006-12-14 at 20:30 -0600, Michal Sabala wrote: > Hello LKML, > > I am observing processes entering uninterruptible sleep apparently due > to an unrelated application using mmap over nfs. Applications in > "uninterruptible sleep" hang indefinitely while other applications > continue working properly. > > The code causing the mmap nfs hangs does the following: > (as replicated by the included test-mmap.c file) > > 1. create file on nfs (file_A, descr_A) > 2. make file_A a sparse 200MB file > 3. mmap descr_A > 4. close descr_A > 5. unlink file_A > 6. memcpy 200MB to mmaped buffer > 7. create a second file on nfs (file_B, descr_B) > 8. write() 200MB from mmaped buffer to descr_B > 9. close descr_B > 10. munmap first file > > This code may need to be ran tens to hundred runs to trigger the condition. > > During the execution of the above code, unrelated applications enter > uninterruptible sleep (D) - usually firefox2.0, Xorg/XFree86, gimp2.2, gconfd > or bash; probably the most active processes. > > `dmesg` shows nothing of interest. > > `free` shows anywhere between 1MB and 80MB of memory still remaining > free when the problem occurs. > > `cat /proc/*PID*/wchan` for all hanging processes contains page_sync.
Have you tried an 'echo t >/proc/sysrq-trigger' on a client with one of these hanging processes? If so, what does the output look like? Cheers Trond - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/