On Mon, Oct 25, 2021 at 08:24:26PM +0200, Andreas Gruenbacher wrote:
> > For generic_perform_write() Dave Hansen attempted to move the fault-in
> > after the uaccess in commit 998ef75ddb57 ("fs: do not prefault
> > sys_write() user buffer pages"). This was reverted as it was exposing an
> > ext4 bu
On Fri, Oct 22, 2021 at 8:41 PM Catalin Marinas wrote:
> On Thu, Oct 21, 2021 at 08:00:50PM +0200, Andreas Gruenbacher wrote:
> > On Thu, Oct 21, 2021 at 7:09 PM Catalin Marinas
> > wrote:
> > > This discussion started with the btrfs search_ioctl() where, even if
> > > some bytes were written in
On Fri, Oct 22, 2021 at 9:23 PM Linus Torvalds
wrote:
> On Fri, Oct 22, 2021 at 8:06 AM Catalin Marinas
> wrote:
> > Probing only the first byte(s) in fault_in() would be ideal, no need to
> > go through all filesystems and try to change the uaccess/probing order.
>
> Let's try that. Or rather:
commit
On Fri, Oct 22, 2021 at 8:07 PM Catalin Marinas wrote:
> On Wed, Oct 20, 2021 at 08:19:40PM -1000, Linus Torvalds wrote:
> > On Wed, Oct 20, 2021 at 12:44 PM Catalin Marinas
> > wrote:
> > >
> > > However, with MTE doing both get_user() every 16 bytes and
> > > gup can get pretty expensive
