On Thu, Nov 20, 2014 at 3:39 AM, Christian Borntraeger
wrote:
>
> So It looks like we could make a change to ACCESS_ONCE. Would something like
>
> CONFIG_ARCH_SCALAR_ACCESS_ONCE be a good start?
No, if it's just a handful of places to be fixed, let's not add config
options for broken cases.
> Th
Am 10.11.2014 um 22:07 schrieb Linus Torvalds:
[...]
> So before blacklisting any compilers, let's first see if
>
> (a) we can actually make it a real rule that we only use ACCESS_ONCE on
> scalars
> (b) we can somehow enforce this with a compiler warning/error for mis-uses
>
> For example, th
On Tue, 11 Nov 2014 16:36:06 -0800
Linus Torvalds wrote:
> On Tue, Nov 11, 2014 at 4:33 PM, Linus Torvalds
> wrote:
> >
> > I guess as a workaround it is fine, as long as we don't lose sight of
> > trying to eventually do a better job.
>
> Oh, and when it comes to the actual gcc bug - do you ha
Am 12.11.2014 um 01:36 schrieb Linus Torvalds:
> On Tue, Nov 11, 2014 at 4:33 PM, Linus Torvalds
> wrote:
>>
>> I guess as a workaround it is fine, as long as we don't lose sight of
>> trying to eventually do a better job.
>
> Oh, and when it comes to the actual gcc bug - do you have any reason
>
On Tue, Nov 11, 2014 at 4:33 PM, Linus Torvalds
wrote:
>
> I guess as a workaround it is fine, as long as we don't lose sight of
> trying to eventually do a better job.
Oh, and when it comes to the actual gcc bug - do you have any reason
to believe that it's somehow triggered more easily by somet
On Tue, Nov 11, 2014 at 1:16 PM, Christian Borntraeger
wrote:
>
> Are you ok with the patch as is in kvm/next for the time being or shall
> we revert that and replace it with the .val scheme?
Is that the one that was quoted at the beginning of the thread, that
uses barrier()?
I guess as a workar
Am 10.11.2014 um 22:07 schrieb Linus Torvalds:
> On Mon, Nov 10, 2014 at 12:18 PM, Christian Borntraeger
> wrote:
>>
>> Now: I can reproduces belows miscompile on gcc46 and gcc 47
>> gcc 45 seems ok, gcc 48 is fixed. This makes blacklisting
>> a bit hard, especially since it is not limited to s39
On Mon, Nov 10, 2014 at 01:07:33PM -0800, Linus Torvalds wrote:
> On Mon, Nov 10, 2014 at 12:18 PM, Christian Borntraeger
> wrote:
> >
> > Now: I can reproduces belows miscompile on gcc46 and gcc 47
> > gcc 45 seems ok, gcc 48 is fixed. This makes blacklisting
> > a bit hard, especially since it
On Mon, Nov 10, 2014 at 12:18 PM, Christian Borntraeger
wrote:
>
> Now: I can reproduces belows miscompile on gcc46 and gcc 47
> gcc 45 seems ok, gcc 48 is fixed. This makes blacklisting
> a bit hard, especially since it is not limited to s390, but
> covers all architectures.
> In essence ACCESS_