Re: 2.5.40: raid0_make_request bug and bad: scheduling while atomic!

From: Helge Hafting (helgehaf@aitel.hist.no)
Date: Sun Oct 06 2002 - 06:20:33 EST


Miquel van Smoorenburg wrote:
>
> I'm trying to test 2.5.40 on a NNTP peering server that pumps
> hundreds of gigs per day over the network. Interested to see
> if I can increase that with 2.5 ;)
>
> Unfortunately my history databases etc are on RAID0:
>
> raid0_make_request bug: can't convert block across chunks or bigger than 32k 8682080 24
> raid0_make_request bug: can't convert block across chunks or bigger than 32k 8679792 24
>
> This appears to be a known problem, but I couldn't find a pointer
> to a solution anywhere. Scared, I ran fsck -f /dev/md0,
> saw no errors, and booted back to 2.4.19

The workaround is to force BIO's to be no bigger than a page.
That limits performance, but it should still be somewhat better
than the pre-bio times.

This used to be fixable in mpage.c, where a comment
explained what to to in precense of "braindead drivers"
But mpage.c changed sometime between 2.5.36 and 2.5.39.

Now the new include/linux/bio.h has the following:
#define BIO_MAX_PAGES (256)
I tried substituting (1) for (256), but it didn't help.
So I don't mount raid-0 right now.

Helge Hafting
-
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 : Mon Oct 07 2002 - 22:00:53 EST