Re: [PATCH] xen/blback: Fit the important information of the thread in 17 characters

From: Roger Pau MonnÃ
Date: Fri Feb 19 2016 - 10:40:15 EST


El 17/2/16 a les 17:31, Konrad Rzeszutek Wilk ha escrit:
> The processes names are truncated to 17, while we had the length
> of the process as name 20 - which meant that while we filled
> it out with various details - the last 3 characters (which had
> the queue number) never surfaced to the user-space.
>
> To simplify this and be able to fit the device name, domain id,
> and the queue number we remove the 'blkback' from the name.
>
> Prior to this patch the device name is "blkback.<domid>.<name>"
> for example: blkback.8.xvda, blkback.11.hda.
>
> With the multiqueue block backend we add "-%d" for the queue.
> But sadly this is already way past the limit so it gets stripped.
>
> Possible solution had been identified by Ian:
> http://lists.xenproject.org/archives/html/xen-devel/2015-05/msg03516.html
>
> "
> If you are pressed for space then the "xvd" is probably a bit redundant
> in a string which starts blkbk.
>
> The guest may not even call the device xvdN (iirc BSD has another
> prefix) any how, so having blkback say so seems of limited use anyway.
>
> Since this seems to not include a partition number how does this work in
> the split partition scheme? (i.e. one where the guest is given xvda1 and
> xvda2 rather than xvda with a partition table)
>
> [It will be 'blkback.8.xvda1', and 'blkback.11.xvda2']
>
> Perhaps something derived from one of the schemes in
> http://xenbits.xen.org/docs/unstable/misc/vbd-interface.txt might be a
> better fit?
>
> After a bit of discussion (see
> http://lists.xenproject.org/archives/html/xen-devel/2015-12/msg01588.html)
> we settled on dropping the "blback" part.
>
> This will make it possible to have the <domid>.<name>-<queue>:
>
> [1.xvda-0]
> [1.xvda-1]
>
> And we enough space to make it go up to:
>
> [32100.xvdfg9-5]
>
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

According to:

http://lists.xenproject.org/archives/html/xen-devel/2015-05/msg03505.html

Should this have a:

Reported-by: Jan Beulich <jbeulich@xxxxxxxx>

Thanks!