lkml.org 
[lkml]   [2018]   [May]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 00/13] convert block layer to bioset_init()/mempool_init()
On Mon, May 21, 2018 at 02:24:32PM -0400, Mike Snitzer wrote:
> Every single data structure change in this series should be reviewed for
> unforeseen alignment consequences. Jens seemed to say that is
> worthwhile. Not sure if he'll do it or we divide it up. If we divide
> it up a temp topic branch should be published for others to inspect.
>
> Could be alignment hasn't been a historic concern for a bunch of the
> data structures changed in this series.. if so then all we can do is fix
> up any obvious potential for false sharing.

Honestly, I almost never worry about alignment... the very few times I do care,
I use __cacheline_aligned_in_smp.

If alignment is a concern in any of those structs, there really ought to be a
comment indicating it. I very much doubt anything I touched was performance
sensitive enough for it to be an issue, though. And if there is a performance
impact, it should be oughtweighed by the reduced pointer chasing.

If you disagree, I don't mind leaving the device mapper patch out, it really
makes no difference to me. I could glance over for alignment issues but I feel
like my analysis would not be terribly valuable to you considering I've already
said my position on alignment is "meh, don't care" :)

\
 
 \ /
  Last update: 2018-05-22 01:39    [W:0.132 / U:0.104 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site