Hi Vineet, On 09/03/2013 09:34 AM, Vineet Gupta wrote: > However assuming we are going ahead with debugging this - can you > please confirm whether you see the issue on x86 as well as I have not > tested that ? I vaguely remember one of your earlier posts suggested > you did Thx, -Vineet I'm unable to reproduce the issue so far. I ran - something like 4000 stock msgctl08 with 4 cores on x86. - a few runs with modified msgctl08 with either slowed down reader or slowed down writer threads. (i.e.: force queue full or queue empty waits). - a few runs (modified&unmodified) with all but one core taken offline. I have not yet tested with PREEMPT enabled. A few more ideas: - what is the output of ipcs -q? Are the queues empty or full? - what is the output of then WCHAN field with ps when it hangs? Something like / #ps/ -o pid,f,stat,pcpu,pmem,psr,/wchan/=/WIDE/-/WCHAN/ -o comm,args -- Manfred