Hollow processes
Quoted 3 lines
It's impossible to check what the process is (trying to read
/proc/{pid}/{anyting}causes reading process to hang in the same way (so we have now 2 hanging processes).
Have you tried SysRQ+showTasks? That dumps the kernel stack. You can convert the numbers to names with ksymoops, or often klogd will convert them and the result is in /var/log/messages.
What exactly hangs?
Could you run
strace ls /proc/1234 strace cat /proc/1234/maps strace ls /proc/1234/fd -l
Which syscall hangs?
SMP or UP?
Signature · 1 line
Manfred
----- Original Message -----
From: "Manfred Spraul" <[email protected]>
Quoted 11 lines
Quoted 3 lines
It's impossible to check what the process is (trying to read
/proc/{pid}/{anyting}causes reading process to hang in the same way (so we have now 2 hanging processes).Have you tried SysRQ+showTasks? That dumps the kernel stack. You can convert the numbers to names with ksymoops, or often klogd will convert them and the result is in
/var/log/messages.What exactly hangs?
Could you run
Quoted 6 lines
strace ls
/proc/1234
strace cat/proc/1234/maps
strace ls/proc/1234/fd-lWhich syscall hangs?
SMP or UP?
It's UP machine with UP kernel. I haven't tried it now strace'ing 'cat /proc/1234/cmdline' (on 2.5.15) but as I remember from earlier kernels it hanged on file reading processes. I'll try to make some additional tests as soon as I'll be back from short vacation
ls'ing /proc/1234 doesn't hangs but ls -al does.
BTW: from my earlier post:
<cut>mremap(0x407c5000, 8192, 12288, MREMAP_MAYMOVE) = 0x407c1000
brk(0x82e5000) = 0x82e5000
brk(0x82e6000) = 0x82e6000old_mmap(NULL, 135168, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x407dc000
mremap(0x407ce000, 8192, 12288, MREMAP_MAYMOVE
</cut>
This is strace poldek on 2.5.11 kernel (behaviour is the same) WKP.S. now I can't reproduce it (on 2.5.15) as it's glibc compilation and it takes far too long and has many subprocesses, but poldek issue on 2.5.11/12 was reproductible.
WK