Re: [PATCH 2/2] Arm32: tidy the memset() macro

[Julien Grall <julien@xxxxxxx>]

Hi Jan,

On 19/08/2022 09:31, Jan Beulich wrote:
> On 19.08.2022 10:24, Julien Grall wrote:
> > On 19/08/2022 09:11, Jan Beulich wrote:
> > > On 19.08.2022 10:06, Julien Grall wrote:
> > > > On 19/08/2022 09:02, Jan Beulich wrote:
> > > > > On 19.08.2022 09:58, Julien Grall wrote:
> > > > > > On 19/08/2022 08:50, Jan Beulich wrote:
> > > > > > > - add parentheses where they were missing (MISRA)
> > > > > > > - make sure to evaluate also v exactly once (MISRA)
> > > > > > > - remove excess parentheses
> > > > > > > - rename local variables to not have leading underscores
> > > > > > > - apply Xen coding style
> > > > > > This code has been taken from Linux. From you write above, I don't see
> > > > > > any strong reason for us to modify it (even if it is small).
> > > > > At least the MISRA issues want addressing, I suppose. Plus I wasn't
> > > > > able to spot the macro in Linux anymore (nor __memzero()), so to me
> > > > > there seemed to be little point to consider keeping anything "in sync"
> > > > > here.
> > > > I read the last part as we want a re-sync of the code (we haven't done
> > > > one in the past couple of years).
> > > I'm afraid I'm now really confused: Which last part? I don't see how
> > > any of what I have said could be read that way. Quite the opposite:
> > > By stating that Linux doesn't have this macro anymore, isn't it quite
> > > clear that there's nothing to re-sync against?
> > Your view here if we will never re-sync the code. This is incorrect, we
> > still want to keep it close so we can benefit from improvement in the
> > Linux code. So if you start tweaking the code just for coding style
> > purpose, it will just make it more difficult for us (I appreciate this
> > is limited here).
> >
> > In this case, Linux has removed __memzero() is patch ff5fdafc9e97 "ARM:
> > 8745/1: get rid of __memzero()" because the performance difference with
> > memset() was limited. For Xen, I think we should also remove the function.
> >
> > With that, this patch becomes pointless.
> Of course. I could have named this as an alternative in a post-commit-
> message remark ... Looking forward to the re-syncing to be done then,
> at which point I'll happily drop this patch.
I will add it in my queue. I don't think this will reach 4.17 (unless 
someone else has time).
Cheers,

--
Julien Grall