Re: O_NONBLOCK with Ext3

From: Jeff Moyer
Date: Fri Jun 11 2010 - 14:56:40 EST


"Yedire, Sandeep" <syedire@xxxxxxxxx> writes:

> Hi ALL,
> I am currently using o_nonblock flag for writing a file of 64MB over a
> flash device. Flash is formatted with ext3 filesystem with default
> options.
> When instrumented the driver code for collecting the erase/write count
> at sector level. I noticed that o_nonblock has no effect on this
> count. There is no difference in erase/write count with o_nonblock
> flag or without this flag.
> When selected Ext2 as filesystem I noticed a significant difference in
> the erase/write count.
> There were more updates with o_nonblock and test application was
> faster. I could confirm this by checking the Dirty page limit in the
> background. It was updating faster in case of Ext2 not incase of Ext3.
>
> Can any one explain on o_nonblock flag in case of Ext3 filesystem?

The O_NONBLOCK flag should be ignored when opening files on a file
system. I'm not sure how to explain your observations.

What exactly were you trying to accomplish?

Cheers,
Jeff
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/