Messages in this thread | | | Date | Wed, 6 Jul 2022 17:58:49 +0100 | Subject | Re: [PATCH] nvme: Fix nvme_setup_command metadata trace event for cdw10 | From | John Garry <> |
| |
On 06/07/2022 17:44, Keith Busch wrote: > On Wed, Jul 06, 2022 at 06:34:34PM +0200, Christoph Hellwig wrote: >> On Wed, Jul 06, 2022 at 10:26:09AM -0600, Keith Busch wrote: >>> On Wed, Jul 06, 2022 at 06:18:25PM +0200, Christoph Hellwig wrote: >>>> On Wed, Jul 06, 2022 at 10:13:22AM -0600, Keith Busch wrote: >>>>> Did you test what the trace looks like afte this? We're losing valuable trace >>>>> data here. The field is supposed to get CDW's 10 - 15, so that's 24 bytes.
ok, I just thought it was a typo, but did not know why you were using an array macro.
> I >>>>> don't know why it cares that the address of the field being read is only 4 >>>>> bytes; we want everything that comes after it too. >>>> >>>> Because accesses should not spawn boundaries of members in structs unless >>>> copying the entire struct. If we want to trace the various fields we >>>> need to individually assign them. >>>> >>>> Anyway, I'm dropping this patch from nvme-5.19 for now to let the >>>> discussion conclude. >>> >>> How about this instead? >> >> Maybe a better option would be to use struct_group(). > > Good call, I'd never used that macro before. The result produces anonymous > unions like I just proposed, so yes, I like that option. > .
The warning hints at using struct_group() also ...
Anyway, Keith, do you want to write a new patch or shall I?
Thanks, John
| |