Re: b_dev vs. b_rdev confusion

From: Tim Pepper (tpepper@vato.org)
Date: Tue Jun 19 2001 - 13:25:11 EST


On Tue, 19 Jun 2001 tpepper@vato.org wrote:

> All of the md code looks like it copies the buffer head, setting
> b_dev=b_rdev="real device" in the new bh and leaving b_dev==b_rdev="logical
> device" in the original bh. I'm assuming they do this for a reason, but
> it would be nice from a performance standpoint to just touch b_rdev and
> b_end_io and be done. Is there something I'm missing which necessitates the
> copy?

Oops...I take that back. In the md code for raid1, raid5 and multipath
I see copies, but not in lvm or linear.

Tim

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



This archive was generated by hypermail 2b29 : Sat Jun 23 2001 - 21:00:25 EST