Re: [edk2-devel] [PATCH] MdePkg/Include: AARCH64: disable outline atomics on GCC 10.2+

["Liming Gao" <liming.gao@intel.com>]

Ard:
  First, Lefi has clarified the request. This patch doesn't need to catch the stable tag. 

  Second, I plan to wait 1~2 days to collect the feedback, the merge the changes. I want to avoid revert change. 
  I don't mean to merge them, then immediately create the stable tag. Sorry if I bring confuse to you. 

  Last, on current plan https://edk2.groups.io/g/devel/message/60474, I will merge two patches tomorrow (06-02), then create the stable tag (06-03).

Thanks
Liming
> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Ard Biesheuvel
> Sent: Monday, June 1, 2020 6:32 PM
> To: Gao, Liming <liming.gao@intel.com>; devel@edk2.groups.io; lersek@redhat.com; Leif Lindholm <leif@nuviainc.com>
> Cc: philmd@redhat.com; mliska@suse.cz; Kinney, Michael D <michael.d.kinney@intel.com>; afish@apple.com
> Subject: Re: [edk2-devel] [PATCH] MdePkg/Include: AARCH64: disable outline atomics on GCC 10.2+
> 
> On 5/30/20 5:10 PM, Gao, Liming wrote:
> > Ard:
> >    Lefi requests to catch this change into 202005 stable tag. I also highlight this request in hard feature freeze notice mail
> https://edk2.groups.io/g/devel/message/60421.
> >
> >    If no objection before the middle of next week (2020-06-03), this patch can be merged with the updated comments.
> >
> 
> If the intent is to allow things to stabilize a bit with this patch
> applied, before creating the tag, then the patch should be pushed
> earlier, no?
> 
> Then, we give it a few days so that we can revert it again if anyone
> finds any issues with it.
> 
> Pushing it right before creating the tag does not sound to me like the
> correct way to approach this.
> 
> 
> 
> >> -----Original Message-----
> >> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Ard Biesheuvel
> >> Sent: Saturday, May 30, 2020 12:51 AM
> >> To: Gao, Liming <liming.gao@intel.com>; devel@edk2.groups.io; lersek@redhat.com; Leif Lindholm <leif@nuviainc.com>
> >> Cc: philmd@redhat.com; mliska@suse.cz; Kinney, Michael D <michael.d.kinney@intel.com>; afish@apple.com
> >> Subject: Re: [edk2-devel] [PATCH] MdePkg/Include: AARCH64: disable outline atomics on GCC 10.2+
> >>
> >> On 5/29/20 4:29 PM, Gao, Liming wrote:
> >>> Ard:
> >>>
> >>>> -----Original Message-----
> >>>> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Ard Biesheuvel
> >>>> Sent: Friday, May 29, 2020 1:47 PM
> >>>> To: devel@edk2.groups.io; Gao, Liming <liming.gao@intel.com>; lersek@redhat.com; Leif Lindholm <leif@nuviainc.com>
> >>>> Cc: philmd@redhat.com; mliska@suse.cz
> >>>> Subject: Re: [edk2-devel] [PATCH] MdePkg/Include: AARCH64: disable outline atomics on GCC 10.2+
> >>>>
> >>>> On 5/29/20 5:18 AM, Liming Gao via groups.io wrote:
> >>>>> Leif:
> >>>>>     I get the point that the linux distribution default GCC version may be 10 or above. Without this fix, those developers can’t
> pass
> >>>> build edk2-stable202005. So, you think this is a critical issue to catch stable tag 202005.
> >>>>>
> >>>>> Ard:
> >>>>>      For this patch, I have two minor comments.
> >>>>> 1) I suggest to remove Link: https://bugzilla.tianocore.org/show_bug.cgi?id=2723 from comments, because this information has
> >>>> been in the commit message.
> >>>>
> >>>> I think it would be helpful to keep it but I won't insist.
> >>>>
> >>>
> >>> I agree this is useful. But, we record it in the commit message. I prefer to remove this link from source code.
> >>> With this change, Reviewed-by: Liming Gao <liming.gao@intel.com>
> >>>
> >>
> >>
> >> Works for me.
> >>
> >> I will send a v2 after the stable tag is released.
> >>
> >>
> >>>>> 2) Can we think __GNUC_MINOR__ is always defined? Do we need to check its value after check whether it is defined or not?
> >>>>>
> >>>>
> >>>> Yes __GNUC_MINOR__ is always defined.
> >>>>
> >>>>
> >>>>
> >>>>> -----Original Message-----
> >>>>> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Laszlo Ersek
> >>>>> Sent: 2020年5月29日 4:03
> >>>>> To: Leif Lindholm <leif@nuviainc.com>
> >>>>> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>; devel@edk2.groups.io; Gao, Liming <liming.gao@intel.com>;
> philmd@redhat.com;
> >>>> mliska@suse.cz
> >>>>> Subject: Re: [edk2-devel] [PATCH] MdePkg/Include: AARCH64: disable outline atomics on GCC 10.2+
> >>>>>
> >>>>> On 05/28/20 12:05, Leif Lindholm wrote:
> >>>>>> On Wed, May 27, 2020 at 11:12:23 +0200, Laszlo Ersek wrote:
> >>>>>>>>>> Oh and I think both this patch and the assembly language
> >>>>>>>>>> implementation for the atomics should be delayed after the stable
> >>>>>>>>>> tag. gcc-10 is a new toolchain; so even if we don't introduce a
> >>>>>>>>>> new toolchain tag such as
> >>>>>>>>>> GCC10 for it, whatever we do in order to make it work, that's
> >>>>>>>>>> feature enablement in my book.
> >>>>>>>>>
> >>>>>>>>> Works for me. By the time the next stable tag comes around, early
> >>>>>>>>> adopters that are now on GCC 10.1 will likely have moved to 10.2 by
> >>>>>>>>> that time, and so we may not need the assembly patch at all.
> >>>>>>>>
> >>>>>>>> I'm not ecstatic that we'll be releasing the first stable tag known
> >>>>>>>> to break with current toolchains.
> >>>>>>>
> >>>>>>> If this breakage affects "current toolchains", then why was
> >>>>>>> <https://bugzilla.tianocore.org/show_bug.cgi?id=2723> only reported
> >>>>>>> on 2020-May-19, four days into the soft feature freeze?
> >>>>>>
> >>>>>> I agree the timing is crap.
> >>>>>>
> >>>>>>>> This isn't just affecting random crazies pulling latest toolchains
> >>>>>>>> down, but people using their distro defaults (native or cross).
> >>>>>>>
> >>>>>>> ... "people using their distro defaults" to *not* build upstream edk2
> >>>>>>> until 2020-May-19, apparently.
> >>>>>>
> >>>>>> Or distro defaults changing in between. I mean, we could say "Arch is
> >>>>>> the same as any other distro's unstable", but I wouldn't want to go
> >>>>>> down that route - I know people who use it for developing also for
> >>>>>> qemu and linux.
> >>>>>>
> >>>>>> Argh, I also just realised the error report I saw two days after Ard's
> >>>>>> intrinsics patch hit the list was not a public report. Yes, if this
> >>>>>> had affected only in-development/unstable distributions, I agree this
> >>>>>> isn't something we should try to deal with upstream.
> >>>>>>
> >>>>>>>> I don't recall if 10.1 ended up being default in F32, but it was
> >>>>>>>> definitely included. In Arch, it does appear default.
> >>>>>>>>
> >>>>>>>> Debian/Ubuntu are unaffected in their stable releases.
> >>>>>>>>
> >>>>>>>> I agree it's a transitional issue, but I would really prefer to have
> >>>>>>>> the intrinsics included in the release.
> >>>>>>>
> >>>>>>> OK, let's delay the release then, by a few days. I agree the present
> >>>>>>> patch may qualify as a bugfix, but the other patch with the assembly
> >>>>>>> language intrinsics doesn't. If it's really that important to have in
> >>>>>>> the upcoming stable tag, then it's worth delaying the tag for. I'm
> >>>>>>> fine delaying the release for it; it wouldn't be without precedent.
> >>>>>>
> >>>>>> I would argue it *is* a bugfix, since it only has an effect on builds
> >>>>>> that would otherwise fail.
> >>>>>
> >>>>> OK. That's a good argument. From my POV, feel free to merge (both patches).
> >>>>>
> >>>>> Thanks
> >>>>> Laszlo
> >>>>>
> >>>>>> But I also do think it is important enough to delay the release if we
> >>>>>> feel that is necessary.
> >>>>>>
> >>>>>> /
> >>>>>>        Leif
> >>>>>>
> >>>>>>> Also, I think Ard's assembly language patch needs a Tested-by from
> >>>>>>> Gary at the least (reporter of TianoCore#2723). Please reach out to
> >>>>>>> him in that thread.
> >>>>>>>
> >>>>>>> ... More precisely, please *ping* Gary for a Tested-by in that
> >>>>>>> thread, because Ard CC'd him from the start, and even credited Gary
> >>>>>>> in the commit message.
> >>>>>>>
> >>>>>>> Thanks,
> >>>>>>> Laszlo
> >>>>>>>
> >>>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>
> >>>>
> >>>>
> >>>
> >>
> >>
> >>
> >
> 
> 
>