[PVFS2-developers] help needed on PVFS2 file data I/O trace collection

[Peng Gu]

Hi Sam,

This is exactly what I was looking for. Thank you very much!

Peng

On 1/17/06, Sam Lang <slang at mcs.anl.gov> wrote:
>
> Hi Peng,
>
> PVFS2 uses Asynchronous I/O to perform reads and writes of the actual
> data.  The call to look for is lio_listio in dbpf-bstream.c, but
> tracing that may not be what you want since it just posts the I/O
> operation.  Service of the actual I/O is done in a separate AIO
> thread at which point the aio_progress_notification function is
> called to specify completion.  If you just want to trace I/O calls,
> there's already an event tracing system in place, although it may not
> give you precisely what you want.  The way to turn it on is with the
> pvfs2-set-eventmask util in src/apps/admin.  I think for trove you
> can do:
>
> pvfs2-set-eventmask -m <mountpoint>  -a 0x4 -o 0xFFFF
>
> That should turn on the trove api mask at least.  You can find the
> mask definitions in include/pvfs2-event.h.
>
> -sam
>