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" :)
