linux io_submit syscall duration

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Bnejamin hello.

My name is raz and i have encountered a problem with  io_submit.
The maximum duration of a single io_submit operation when
heavily stressing the system with large number of big (1MB) ios,
reaches several hundereds ms.

I have been profiling it and it seems that the problem is the
file->f_op->aio_read operation,
a call that is made in fs/aio.c when coming from:
sys_io_submit -->
  io_submit_one -->
	  aio_run_iocb -->
  		 *retry


The test is initiating several hundered 1MB IOs over a single block device.

I understand that the assumption made was aio_read is asynchronous and no
delay will occure, but isn't possible to do it in the workqueue context ?

would appreciate your help.
thank you

raz
-
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/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux