On Thu, 2021-09-16 at 14:36 +, David Laight wrote:
> > Does userspace accesses non-cached memory directly ?
>
>
> It probably can if a driver mmaps PCI space directly into user space.
>
> That certainly works on x86-64.
The posterchild for that is Xorg
Cheers,
Ben.
From: Christophe Leroy
> Sent: 16 September 2021 08:24
>
> Le 16/09/2021 à 09:16, Benjamin Herrenschmidt a écrit :
> > On Thu, 2021-09-16 at 17:15 +1000, Benjamin Herrenschmidt wrote:
> >> On Wed, 2021-09-15 at 16:31 +0200, Christophe Leroy wrote:
> >>> dcbz instruction shouldn't be used on
Le 16/09/2021 à 09:16, Benjamin Herrenschmidt a écrit :
On Thu, 2021-09-16 at 17:15 +1000, Benjamin Herrenschmidt wrote:
On Wed, 2021-09-15 at 16:31 +0200, Christophe Leroy wrote:
dcbz instruction shouldn't be used on non-cached memory. Using
it on non-cached memory can result in alignment
On Thu, 2021-09-16 at 17:15 +1000, Benjamin Herrenschmidt wrote:
> On Wed, 2021-09-15 at 16:31 +0200, Christophe Leroy wrote:
> > dcbz instruction shouldn't be used on non-cached memory. Using
> > it on non-cached memory can result in alignment exception and
> > implies a heavy handling.
> >
> >
On Wed, 2021-09-15 at 16:31 +0200, Christophe Leroy wrote:
> dcbz instruction shouldn't be used on non-cached memory. Using
> it on non-cached memory can result in alignment exception and
> implies a heavy handling.
>
> Instead of silentely emulating the instruction and resulting in high
>
dcbz instruction shouldn't be used on non-cached memory. Using
it on non-cached memory can result in alignment exception and
implies a heavy handling.
Instead of silentely emulating the instruction and resulting in high
performance degradation, warn whenever an alignment exception is
taken due to
