Messages in this thread | | | Date | Wed, 6 Jul 2022 10:44:40 -0600 | From | Keith Busch <> | Subject | Re: [PATCH] nvme: Fix nvme_setup_command metadata trace event for cdw10 |
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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. 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.
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