[PATCH 1/2] dm-band: The I/O bandwidth controller: Source code
elendil at planet.nl
Wed Jan 23 05:33:28 PST 2008
I'm not qualified to comment on the code, but here are some suggestions on
config option and comments.
Ryo Tsuruta wrote:
> +config DM_BAND
> + tristate "I/O band width control "
(it seems to be used correctly elsewhere, but you may want to double-check)
> + depends on BLK_DEV_DM
> + ---help---
> + Any processes or cgroups can use the same storage
> + with its band-width fairly shared.
The help should probably be a bit more verbose as this does not tell anybody
much who has not already read the documentation.
Maybe something like:
This device-mapper target allows to define how the
available bandwith of a storage device should be
shared between processes or cgroups.
Information on how to use dm-band is available in:
> + * The following functiotons determine when and which BIOs should
> + * be submitted to control the I/O flow.
> + * It is possible to add a new I/O scheduling policy with it.
> + * <Method> <description>
> + * g_can_submit : To determine whether a given group has a right to
s/a right/the right/
> + * submit BIOs.
> + * The larger return value the higher priority to submit.
> + * Zero means it has no right.
"The larger the return value, the higher the priority [...]"
> + * g_prepare_bio : Called right before submitting each BIO.
> + * g_restart_bios : Called when there exist some BIOs blocked but none of
> + * can't be submitted now.
s/when there exist some BIOs blocked/if some BIOs exist that are blocked/ ?
"none of them can't" : the double negative looks incorrect (and should be
> + * This method have to do something to restart to submit BIOs.
"has to do something" : that's rather vague...
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