On 12/30/2015 11:34 AM, Thierry BERTAUD wrote:
Hello Jens,
That's expected - when the main thread goes to sleep, it checks for this
status dump file. If it exists, then it'll show the current summary of
stats, then unlink it.
Thanks for explain this point.
Just to confirm my understanding the following option with engine 'posixaio'
iodepth=128 and numjobs=128 =>
I don't use 'thread' option so i think with iodpeth=128 the main fio process will fork to create 128 process.
With numjob=128 that imply, i'll clone each forked process from fio (due to iodepth) that's imply 16384 process (128 * 128).
If i use threads enabled, with iodepth=128 the main fio process will create with pthread_create 128 threads for itself.
With numjobs=128, the ain fio process will clone to have 16384 threads into itselft or it will fork to create 128 process and each process has 128 threads.
That's the main thread, what are the IO threads doing?
If i follow disk I/O there are no activities.
This kind of information for fio process can help or not to answer the questions?
The list of thread by process this:
# ps -mo THREAD
USER PID PPID TID ST CP PRI SC WCHAN F TT BND COMMAND
root 9437428 10551472 - A 0 60 1 - 200001 pts/0 - ksh
- - - 18350143 S 0 60 1 - 10400 - - -
padmin 10551472 11534386 - A 0 60 1 - 240001 pts/0 - -rksh
- - - 49873143 S 0 60 1 - 10400 - - -
root 11206870 9437428 - A 1 60 1 - 200001 pts/0 - bash
- - - 48759011 S 1 60 1 - 410400 - - -
root 62914724 11206870 - A 6 63 1 - 200001 pts/0 - ps -mo THREAD
- - - 116850921 R 6 63 1 - 400000 - - -
#
Or thread for a given process like this:
# ps -mp 9437428 -o THREAD
USER PID PPID TID ST CP PRI SC WCHAN F TT BND COMMAND
root 9437428 10551472 - A 0 60 1 - 200001 pts/0 - ksh
- - - 18350143 S 0 60 1 - 10400 - - -
#
I tried to use gdb against the live process but i don't how to progress with it?
I can do gdb against the executable also but i don't know how to progress whit it?
Against the live process it the easiest. Just do gdb -p <pid> and
attach. If you don't use threads from fio, then they will each be a
separate process.
I'll be taking a bit of time off, but I should have access to an AIX
that I can test on sometime next week. What version are you on?
--
Jens Axboe
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