Re: Adaptive read-ahead: benchmarks

[Paolo Ornati]

On Thu, 15 Sep 2005 21:16:51 +0800
WU Fengguang <wfg@xxxxxxxxxxxxxxxx> wrote:

> oprofile() {
>         opcontrol --vmlinux=/temp/kernel/linux-2.6.13ra/vmlinux
>         opcontrol --start
>         opcontrol --reset
>         echo $1 > /proc/sys/vm/readahead_ratio
>         dd if=/temp/kernel/hugefile of=/dev/null bs=$bs
>         opreport -l -o oprofile.$1.$bs /temp/kernel/linux-2.6.13ra/vmlinux
>         opcontrol --stop
> }

just a side note: shouldn't you umount and remount "/temp" to remove
the pagecache? Or is the file so big that it doesn't matter?

PS: instead of unmount/remount you can use "fadvise":
http://www.zip.com.au/~akpm/linux/patches/stuff/ext3-tools.tar.gz

-- 
	Paolo Ornati
	Linux 2.6.14-rc1 on x86_64
-
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/