Re: directio and async io on redhat linux 3 and oracle 9i

yong..._at_yahoo.com wrote:

> Alternatively, try `truss -u:directio a.out`. In the test of my dio
> program, I see
> /1: open("testfile", O_RDONLY) = 3
> /1_at_1: -> libc:directio(0x3, 0x1, 0xd2ff260c, 0xd2f008e9)
> /1: ioctl(3, _ION('f', 76, 0), 0x00000001) = 0
> /1_at_1: <- libc:directio() = 0
> Or try `truss -t!all -u:directio a.out` to remove all syscalls in
> output.

That should do the trick then? I mean, truss for directio()?

BTW, the O_DIRECT is most definitely working with 9.2.0.6 and RHAS3/ext3, unlike what the Oracle availability matrix says.

This is the memory usage with it on a create index:

[nsouto_at_db2]$ free -mt

      total        used   free   shared   buffers   cached
Mem:  3010         978    2031   0        166       514
-/+ buffers/cache: 297    2712
Swap: 2047         0      2047
Total:5057         978    4079

Without O_DIRECT:

[nsouto_at_db2]$ free -mt

      total        used   free   shared   buffers   cached
Mem:  3010         2992   17     0        4         2697
-/+ buffers/cache: 291    2719
Swap: 2047         0      2047
Total:5057         2992   2064

I'd say the difference in mem usage is caused by the O_DIRECT. System totally dedicated, of course: no other users or processes. Received on Mon May 09 2005 - 00:30:12 CDT