On 5/18/21 3:23 PM, Christoph Hellwig wrote:
On Mon, May 17, 2021 at 11:46:35PM +0200, Thomas Hellström wrote:
Apart from the caching aliasing Mattew brought up, doesn't the
remap_pfn_range_xxx() family require the mmap_sem held in write mode since
it modifies the vma structure? remap_io_sg()
On 5/18/21 5:00 PM, Matthew Auld wrote:
On Tue, 18 May 2021 at 14:21, Christoph Hellwig wrote:
On Mon, May 17, 2021 at 06:06:44PM +0100, Matthew Auld wrote:
Looks like it is caused by the validation failure then. Which means the
existing code is doing something wrong in its choice of the pa
On Tue, 18 May 2021 at 14:21, Christoph Hellwig wrote:
>
> On Mon, May 17, 2021 at 06:06:44PM +0100, Matthew Auld wrote:
> > > Looks like it is caused by the validation failure then. Which means the
> > > existing code is doing something wrong in its choice of the page
> > > protection bit. I re
On 5/18/21 3:24 PM, Christoph Hellwig wrote:
On Tue, May 18, 2021 at 08:46:44AM +0200, Thomas Hellström wrote:
And worse, if we prefault a user-space buffer object map using
remap_io_sg() and then zap some ptes using madvise(), the next time those
ptes are accessed, we'd trigger a new call to
On 5/17/21 11:46 PM, Thomas Hellström wrote:
On 5/17/21 3:11 PM, Christoph Hellwig wrote:
On Mon, May 17, 2021 at 04:09:42PM +0300, Serge Belyshev wrote:
Christoph Hellwig writes:
As an ad-hoc experiment: can you replace the call to remap_pfn_range
with remap_pfn_range_notrack (and expor
On 5/17/21 3:11 PM, Christoph Hellwig wrote:
On Mon, May 17, 2021 at 04:09:42PM +0300, Serge Belyshev wrote:
Christoph Hellwig writes:
As an ad-hoc experiment: can you replace the call to remap_pfn_range
with remap_pfn_range_notrack (and export it if you build i915 modular)
in remap_io_sg
On Mon, 17 May 2021 at 14:11, Christoph Hellwig wrote:
>
> On Mon, May 17, 2021 at 04:09:42PM +0300, Serge Belyshev wrote:
> > Christoph Hellwig writes:
> >
> > > As an ad-hoc experiment: can you replace the call to remap_pfn_range
> > > with remap_pfn_range_notrack (and export it if you build i
This patch cause "x86/PAT : surfaceflinger:1440 map pfn RAM range req
write-combining for [mem 0x064a2000-0x064a2fff], got write-back" problem.
my 2GB ram Bay trail z3735f tablet runing on android-x86, "i915: fix
remap_io_sg to verify the pgprot" cause this problem.
05-09 02:59:25.099 0
