RE: Direct io on block device has performance regression on 2.6.x kernel
From: Chen, Kenneth W
Date: Wed Mar 09 2005 - 20:55:59 EST
Andrew Morton wrote on Wednesday, March 09, 2005 5:34 PM
> What are these percentages? Total CPU time? The direct-io stuff doesn't
> look too bad. It's surprising that tweaking the direct-io submission code
> makes much difference.
Percentage is relative to total kernel time. There are three DIO functions
showed up in the profile:
> hm. __blockdev_direct_IO() doesn't actually do much. I assume your damn
> compiler went and inlined direct_io_worker() on us.
We are using gcc version 3.4.3. I suppose I can finger point gcc ? :-P
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/