Re: Bio pool & scsi scatter gather pool usage

From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Date: Fri Apr 19 2002 - 03:58:36 EST


> But this gets you lowest common denominator sizes for the whole
> volume, which is basically the buffer head approach, chop all I/O up
> into a chunk size we know will always work. Any sort of nasty boundary
> condition at one spot in a volume means the whole thing is crippled
> down to that level. It then becomes a black magic art to configure a
> volume which is not restricted to a small request size.

Its still cheaper to merge bio chains than split them. The VM issues with
splitting them are not nice at all since you may need to split a bio to
write out a page and it may be the last page
-
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 : Tue Apr 23 2002 - 22:00:23 EST