Hello,
I'm sorry for the late reply. I must have missed this mail...
On Wednesday, August 03, 2011 7:44 PM James Bottomley wrote:
[cc to ks-discuss added, since this may be a relevant topic]
On Tue, 2011-07-05 at 14:27 +0200, Arnd Bergmann wrote:
On Tuesday 05 July 2011, Russell King -
On Wed, Aug 03, 2011 at 12:43:50PM -0500, James Bottomley wrote:
I assume from the above that ARM has a hardware page walker?
Correct, and speculative prefetch (which isn't prevented by not having
TLB entries), so you can't keep entries out of the TLB. If it's in
the page tables it can end up
The Contiguous Memory Allocator is a set of helper functions for DMA
mapping framework that improves allocations of contiguous memory chunks.
CMA grabs memory on system boot, marks it with CMA_MIGRATE_TYPE and
gives back to the system. Kernel is allowed to allocate movable pages
within CMA's
[cc to ks-discuss added, since this may be a relevant topic]
On Tue, 2011-07-05 at 14:27 +0200, Arnd Bergmann wrote:
On Tuesday 05 July 2011, Russell King - ARM Linux wrote:
On Tue, Jul 05, 2011 at 09:41:48AM +0200, Marek Szyprowski wrote:
The Contiguous Memory Allocator is a set of helper
The Contiguous Memory Allocator is a set of helper functions for DMA
mapping framework that improves allocations of contiguous memory chunks.
CMA grabs memory on system boot, marks it with CMA_MIGRATE_TYPE and
gives back to the system. Kernel is allowed to allocate movable pages
within CMA's
Hello,
I've just found two nasty bugs in this version of CMA. Sadly, both are the
results of posting the patches in a big hurry. I'm really sorry.
Alignment argument was not passed correctly to the
bitmap_find_next_zero_area() function and there was an ugly bug in the
On Friday 08 July 2011, Russell King - ARM Linux wrote:
On Tue, Jul 05, 2011 at 03:58:39PM +0200, Arnd Bergmann wrote:
If I'm reading your ARM: DMA: steal memory for DMA coherent mappings
correctly, the idea is to have a per-platform compile-time amount
of memory that is reserved purely
Hello,
On Saturday, July 09, 2011 4:57 PM Janusz Krzysztofik wrote:
On Wed, 6 Jul 2011 at 16:59:45 Arnd Bergmann wrote:
On Wednesday 06 July 2011, Nicolas Pitre wrote:
On Wed, 6 Jul 2011, Russell King - ARM Linux wrote:
Another issue is that when a platform has restricted DMA
Dnia poniedziałek, 11 lipca 2011 o 15:47:32 Marek Szyprowski napisał(a):
Hello,
On Saturday, July 09, 2011 4:57 PM Janusz Krzysztofik wrote:
On Wed, 6 Jul 2011 at 16:59:45 Arnd Bergmann wrote:
On Wednesday 06 July 2011, Nicolas Pitre wrote:
On Wed, 6 Jul 2011, Russell King - ARM Linux
Hello,
On Monday, July 11, 2011 9:01 PM Janusz Krzysztofik wrote:
Dnia poniedziałek, 11 lipca 2011 o 15:47:32 Marek Szyprowski napisał(a):
Hello,
On Saturday, July 09, 2011 4:57 PM Janusz Krzysztofik wrote:
On Wed, 6 Jul 2011 at 16:59:45 Arnd Bergmann wrote:
On Wednesday 06
On Wed, 6 Jul 2011 at 16:59:45 Arnd Bergmann wrote:
On Wednesday 06 July 2011, Nicolas Pitre wrote:
On Wed, 6 Jul 2011, Russell King - ARM Linux wrote:
Another issue is that when a platform has restricted DMA regions,
they typically don't fall into the highmem zone. As the
dmabounce
On Tue, Jul 05, 2011 at 03:58:39PM +0200, Arnd Bergmann wrote:
Ah, sorry I missed that patch on the mailing list, found it now in
your for-next branch.
I've been searching for this email to reply to for the last day or
so...
If I'm reading your ARM: DMA: steal memory for DMA coherent mappings
Hello,
On Tuesday, July 05, 2011 1:34 PM Russell King - ARM Linux wrote:
On Tue, Jul 05, 2011 at 09:41:48AM +0200, Marek Szyprowski wrote:
The Contiguous Memory Allocator is a set of helper functions for DMA
mapping framework that improves allocations of contiguous memory chunks.
CMA
On Wednesday 06 July 2011, Marek Szyprowski wrote:
The only problem that might need to be resolved is GFP_ATOMIC allocation
(updating page properties probably requires some locking), but it can be
served from a special area which is created on boot without low-memory
mapping at all. None sane
On Wed, Jul 06, 2011 at 04:09:29PM +0200, Arnd Bergmann wrote:
Maybe you can simply adapt the default location of the contiguous memory
are like this:
- make CONFIG_CMA depend on CONFIG_HIGHMEM on ARM, at compile time
- if ZONE_HIGHMEM exist during boot, put the CMA area in there
- otherwise,
On Wed, 6 Jul 2011, Russell King - ARM Linux wrote:
Another issue is that when a platform has restricted DMA regions,
they typically don't fall into the highmem zone. As the dmabounce
code allocates from the DMA coherent allocator to provide it with
guaranteed DMA-able memory, that would be
On Wednesday 06 July 2011, Russell King - ARM Linux wrote:
On Wed, Jul 06, 2011 at 04:09:29PM +0200, Arnd Bergmann wrote:
Maybe you can simply adapt the default location of the contiguous memory
are like this:
- make CONFIG_CMA depend on CONFIG_HIGHMEM on ARM, at compile time
- if
Hello,
On Wednesday, July 06, 2011 4:09 PM Arnd Bergmann wrote:
On Wednesday 06 July 2011, Marek Szyprowski wrote:
The only problem that might need to be resolved is GFP_ATOMIC allocation
(updating page properties probably requires some locking), but it can be
served from a special area
On Wednesday 06 July 2011, Nicolas Pitre wrote:
On Wed, 6 Jul 2011, Russell King - ARM Linux wrote:
Another issue is that when a platform has restricted DMA regions,
they typically don't fall into the highmem zone. As the dmabounce
code allocates from the DMA coherent allocator to
On Wed, Jul 06, 2011 at 04:56:23PM +0200, Marek Szyprowski wrote:
This will not solve our problems. We need CMA also to create at least one
device private area that for sure will be in low memory (video codec).
You make these statements but you don't say why. Can you please
explain why the
Hello,
On Wednesday, July 06, 2011 5:37 PM Russell King - ARM Linux wrote:
On Wed, Jul 06, 2011 at 04:56:23PM +0200, Marek Szyprowski wrote:
This will not solve our problems. We need CMA also to create at least one
device private area that for sure will be in low memory (video codec).
On Wed, Jul 06, 2011 at 04:51:49PM +0200, Arnd Bergmann wrote:
On Wednesday 06 July 2011, Russell King - ARM Linux wrote:
On Wed, Jul 06, 2011 at 04:09:29PM +0200, Arnd Bergmann wrote:
Maybe you can simply adapt the default location of the contiguous memory
are like this:
- make
On Wed, 06 Jul 2011 18:05:00 +0200, Christoph Lameter c...@linux.com wrote:
ZONE_DMA is a zone for memory of legacy (crippled) devices that cannot
DMA into all of memory (and so is ZONE_DMA32). Memory from ZONE_NORMAL
can be used for DMA as well and a fully capable device would be expected
to
On Wed, 6 Jul 2011, Russell King - ARM Linux wrote:
they typically don't fall into the highmem zone. As the dmabounce
code allocates from the DMA coherent allocator to provide it with
guaranteed DMA-able memory, that would be rather inconvenient.
True. The dmabounce code would
On Wed, 6 Jul 2011, Michal Nazarewicz wrote:
On Wed, 06 Jul 2011 18:05:00 +0200, Christoph Lameter c...@linux.com wrote:
ZONE_DMA is a zone for memory of legacy (crippled) devices that cannot DMA
into all of memory (and so is ZONE_DMA32). Memory from ZONE_NORMAL
can be used for DMA as
On Wednesday 06 July 2011, Russell King - ARM Linux wrote:
On Wed, Jul 06, 2011 at 04:51:49PM +0200, Arnd Bergmann wrote:
On Wednesday 06 July 2011, Russell King - ARM Linux wrote:
I don't see how. The pages get allocated from an unmapped area
or memory, mapped into the kernel address
On Wed, Jul 06, 2011 at 11:05:00AM -0500, Christoph Lameter wrote:
On Wed, 6 Jul 2011, Russell King - ARM Linux wrote:
they typically don't fall into the highmem zone. As the dmabounce
code allocates from the DMA coherent allocator to provide it with
guaranteed DMA-able memory,
On Wed, Jul 06, 2011 at 11:19:00AM -0500, Christoph Lameter wrote:
What I described is the basic memory architecture of Linux. I am not that
familiar with ARM and the issue discussed here. Only got involved because
ZONE_DMA was mentioned. The nature of ZONE_DMA is often misunderstood.
The
On Wed, 6 Jul 2011, Russell King - ARM Linux wrote:
So, ARM is no different from x86, with the exception that the 16MB DMA
zone due to ISA ends up being different sizes on ARM depending on our
restrictions.
Sounds good. Thank you.
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On Wed, 6 Jul 2011, Arnd Bergmann wrote:
On Wednesday 06 July 2011, Russell King - ARM Linux wrote:
On Wed, Jul 06, 2011 at 04:51:49PM +0200, Arnd Bergmann wrote:
On Wednesday 06 July 2011, Russell King - ARM Linux wrote:
I don't see how. The pages get allocated from an unmapped area
On Wednesday 06 July 2011 21:10:07 Nicolas Pitre wrote:
If you get a highmem page, because the cache is VIPT, that page might
still be cached even if it wasn't mapped. With a VIVT cache we must
flush the cache whenever a highmem page is unmapped. There is no such
restriction with VIPT
On Wed, 6 Jul 2011, Arnd Bergmann wrote:
On Wednesday 06 July 2011 21:10:07 Nicolas Pitre wrote:
If you get a highmem page, because the cache is VIPT, that page might
still be cached even if it wasn't mapped. With a VIVT cache we must
flush the cache whenever a highmem page is unmapped.
The Contiguous Memory Allocator is a set of helper functions for DMA
mapping framework that improves allocations of contiguous memory chunks.
CMA grabs memory on system boot, marks it with CMA_MIGRATE_TYPE and
gives back to the system. Kernel is allowed to allocate movable pages
within CMA's
Hello,
On Tuesday, July 05, 2011 9:42 AM Marek Szyprowski wrote:
The Contiguous Memory Allocator is a set of helper functions for DMA
mapping framework that improves allocations of contiguous memory chunks.
CMA grabs memory on system boot, marks it with CMA_MIGRATE_TYPE and
gives back to
On Tue, Jul 05, 2011 at 09:41:48AM +0200, Marek Szyprowski wrote:
The Contiguous Memory Allocator is a set of helper functions for DMA
mapping framework that improves allocations of contiguous memory chunks.
CMA grabs memory on system boot, marks it with CMA_MIGRATE_TYPE and
gives back to
On Tuesday 05 July 2011, Russell King - ARM Linux wrote:
On Tue, Jul 05, 2011 at 09:41:48AM +0200, Marek Szyprowski wrote:
The Contiguous Memory Allocator is a set of helper functions for DMA
mapping framework that improves allocations of contiguous memory chunks.
CMA grabs memory on
On Tue, Jul 05, 2011 at 02:27:44PM +0200, Arnd Bergmann wrote:
It's also a preexisting problem as far as I can tell, and it needs
to be solved in __dma_alloc for both cases, dma_alloc_from_contiguous
and __alloc_system_pages as introduced in patch 7.
Which is now resolved in linux-next, and
On Tuesday 05 July 2011, Russell King - ARM Linux wrote:
On Tue, Jul 05, 2011 at 02:27:44PM +0200, Arnd Bergmann wrote:
It's also a preexisting problem as far as I can tell, and it needs
to be solved in __dma_alloc for both cases, dma_alloc_from_contiguous
and __alloc_system_pages as
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