Displaying 20 results from an estimated 1322 matches for "coherence".
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coherency
2017 Feb 01
4
[PATCH] virtio: Try to untangle DMA coherency
By forcing on DMA API usage for ARM systems, we have inadvertently
kicked open a hornets' nest in terms of cache-coherency. Namely that
unless the virtio device is explicitly described as capable of coherent
DMA by firmware, the DMA APIs on ARM and other DT-based platforms will
assume it is non-coherent. This turns out to cause a big problem for the
likes of QEMU and kvmtool, which generate
2017 Feb 01
4
[PATCH] virtio: Try to untangle DMA coherency
By forcing on DMA API usage for ARM systems, we have inadvertently
kicked open a hornets' nest in terms of cache-coherency. Namely that
unless the virtio device is explicitly described as capable of coherent
DMA by firmware, the DMA APIs on ARM and other DT-based platforms will
assume it is non-coherent. This turns out to cause a big problem for the
likes of QEMU and kvmtool, which generate
2017 Feb 01
3
[PATCH] virtio: Try to untangle DMA coherency
...ns true if "dma-coherent" property was found
- * for this device in DT.
+ * for this device in DT or the device is statically known to be
+ * coherent.
*/
bool of_dma_is_coherent(struct device_node *np)
{
struct device_node *node = of_node_get(np);
+ /*
+ * Check for implicit DMA coherence first, since we don't want
+ * to inherit this.
+ */
+ if (of_device_compatible_match(np, of_device_dma_coherent_tbl)) {
+ of_node_put(node);
+ return true;
+ }
+
while (node) {
- if (of_property_read_bool(node, "dma-coherent")) {
+ if (of_property_read_bool(node, "dma-co...
2017 Feb 01
3
[PATCH] virtio: Try to untangle DMA coherency
...ns true if "dma-coherent" property was found
- * for this device in DT.
+ * for this device in DT or the device is statically known to be
+ * coherent.
*/
bool of_dma_is_coherent(struct device_node *np)
{
struct device_node *node = of_node_get(np);
+ /*
+ * Check for implicit DMA coherence first, since we don't want
+ * to inherit this.
+ */
+ if (of_device_compatible_match(np, of_device_dma_coherent_tbl)) {
+ of_node_put(node);
+ return true;
+ }
+
while (node) {
- if (of_property_read_bool(node, "dma-coherent")) {
+ if (of_property_read_bool(node, "dma-co...
2017 Feb 01
0
[PATCH] virtio: Try to untangle DMA coherency
On Wed, Feb 01, 2017 at 12:25:57PM +0000, Robin Murphy wrote:
> By forcing on DMA API usage for ARM systems, we have inadvertently
> kicked open a hornets' nest in terms of cache-coherency. Namely that
> unless the virtio device is explicitly described as capable of coherent
> DMA by firmware, the DMA APIs on ARM and other DT-based platforms will
> assume it is non-coherent.
2017 Feb 01
0
[PATCH] virtio: Try to untangle DMA coherency
...ound
> - * for this device in DT.
> + * for this device in DT or the device is statically known to be
> + * coherent.
> */
> bool of_dma_is_coherent(struct device_node *np)
> {
> struct device_node *node = of_node_get(np);
>
> + /*
> + * Check for implicit DMA coherence first, since we don't want
> + * to inherit this.
> + */
> + if (of_device_compatible_match(np, of_device_dma_coherent_tbl)) {
> + of_node_put(node);
> + return true;
> + }
> +
> while (node) {
> - if (of_property_read_bool(node, "dma-coherent")) {
&g...
2005 Dec 01
1
squared coherency and cross-spectrum
Hi All,
I have two time series, each has length 354. I tried to calculate the
coherency^2 between them, but the value I got is always 1. On a website,
it says: " Note that if the ensemble averaging were to be omitted, the
coherency (squared) would be 1, independent of the data". Does any of
you know how to specify properly in R in order to get more useful
coherency? The examples in
2017 Feb 08
2
[PATCH] virtio: Try to untangle DMA coherency
On 02/01/2017 08:19 PM, Michael S. Tsirkin wrote:
> On Wed, Feb 01, 2017 at 06:27:09PM +0000, Will Deacon wrote:
>> On Wed, Feb 01, 2017 at 08:09:21PM +0200, Michael S. Tsirkin wrote:
>>> On Wed, Feb 01, 2017 at 12:25:57PM +0000, Robin Murphy wrote:
>>>> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
>>>> index
2017 Feb 08
2
[PATCH] virtio: Try to untangle DMA coherency
On 02/01/2017 08:19 PM, Michael S. Tsirkin wrote:
> On Wed, Feb 01, 2017 at 06:27:09PM +0000, Will Deacon wrote:
>> On Wed, Feb 01, 2017 at 08:09:21PM +0200, Michael S. Tsirkin wrote:
>>> On Wed, Feb 01, 2017 at 12:25:57PM +0000, Robin Murphy wrote:
>>>> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
>>>> index
2017 Feb 01
0
[PATCH] virtio: Try to untangle DMA coherency
On Wed, Feb 01, 2017 at 12:25:57PM +0000, Robin Murphy wrote:
> By forcing on DMA API usage for ARM systems, we have inadvertently
> kicked open a hornets' nest in terms of cache-coherency. Namely that
> unless the virtio device is explicitly described as capable of coherent
> DMA by firmware, the DMA APIs on ARM and other DT-based platforms will
> assume it is non-coherent.
2015 Dec 17
1
[PATCH] virtio_ring: use smp_store_mb
...e weak barriers to use dma_wmb/rmb
> > >
> > > That commit doesn't make any sense. dma_*mb() explicitly does _NOT_
> > > cover the smp_*mb() part.
> > >
> > > Again, look at the ARM definitions, the smp_*mb() primitives use the
> > > inner coherence stuff, while the dma_*mb() primitives use the outer
> > > coherent stuff.
> >
> > Does outer coherent imply inner coherent?
> >
> > > the *mb() primitives cover both.
>
> I do not think so, but lets add Will, he dreams this stuff.
Right, and I don't...
2015 Dec 17
1
[PATCH] virtio_ring: use smp_store_mb
...e weak barriers to use dma_wmb/rmb
> > >
> > > That commit doesn't make any sense. dma_*mb() explicitly does _NOT_
> > > cover the smp_*mb() part.
> > >
> > > Again, look at the ARM definitions, the smp_*mb() primitives use the
> > > inner coherence stuff, while the dma_*mb() primitives use the outer
> > > coherent stuff.
> >
> > Does outer coherent imply inner coherent?
> >
> > > the *mb() primitives cover both.
>
> I do not think so, but lets add Will, he dreams this stuff.
Right, and I don't...
2010 Oct 09
2
[PATCH 1/2] Ocfs2: Add a mount option "coherency=*" for O_DIRECT writes.
Currently, default behavior of O_DIRECT writes was allowing
concurrent writing among nodes, no cluster coherency guaranteed
(no EX locks was taken), it hurts buffered reads on other nodes
by reading stale data from cache.
The new mount option introduce a chance to choose two different
behaviors for O_DIRECT writes:
* coherency=full, as the default value, will disallow
concurrent
2015 Dec 17
2
[PATCH] virtio_ring: use smp_store_mb
...3:49 2015 +0930
> >
> > virtio_ring: Update weak barriers to use dma_wmb/rmb
>
> That commit doesn't make any sense. dma_*mb() explicitly does _NOT_
> cover the smp_*mb() part.
>
> Again, look at the ARM definitions, the smp_*mb() primitives use the
> inner coherence stuff, while the dma_*mb() primitives use the outer
> coherent stuff.
Does outer coherent imply inner coherent?
> the *mb() primitives cover both.
2015 Dec 17
2
[PATCH] virtio_ring: use smp_store_mb
...3:49 2015 +0930
> >
> > virtio_ring: Update weak barriers to use dma_wmb/rmb
>
> That commit doesn't make any sense. dma_*mb() explicitly does _NOT_
> cover the smp_*mb() part.
>
> Again, look at the ARM definitions, the smp_*mb() primitives use the
> inner coherence stuff, while the dma_*mb() primitives use the outer
> coherent stuff.
Does outer coherent imply inner coherent?
> the *mb() primitives cover both.
2011 Jul 11
1
Spectral Coherence
Greetings,
I would like to estimate a spectral coherence between
two timeseries. The stats : spectrum() returns a coh matrix
which estimates coherence (squared).
A basic test which from which i expect near-zero coherence:
x = rnorm(500)
y = rnorm(500)
xts = ts(x, frequency = 10)
yts = ts(y, frequency = 10)
gxy = spectrum( cbind( x...
2017 Feb 09
2
[PATCH] virtio: Try to untangle DMA coherency
On Thu, Feb 09, 2017 at 06:31:18PM +0000, Will Deacon wrote:
> On Thu, Feb 09, 2017 at 08:17:16PM +0200, Michael S. Tsirkin wrote:
> > On Thu, Feb 02, 2017 at 04:40:49PM +0000, Will Deacon wrote:
> > > On Thu, Feb 02, 2017 at 06:30:28PM +0200, Michael S. Tsirkin wrote:
> > > > I am inclined to say, for 4.10 let's revert
> > > >
2017 Feb 09
2
[PATCH] virtio: Try to untangle DMA coherency
On Thu, Feb 09, 2017 at 06:31:18PM +0000, Will Deacon wrote:
> On Thu, Feb 09, 2017 at 08:17:16PM +0200, Michael S. Tsirkin wrote:
> > On Thu, Feb 02, 2017 at 04:40:49PM +0000, Will Deacon wrote:
> > > On Thu, Feb 02, 2017 at 06:30:28PM +0200, Michael S. Tsirkin wrote:
> > > > I am inclined to say, for 4.10 let's revert
> > > >
2017 Feb 09
3
[PATCH] virtio: Try to untangle DMA coherency
On Thu, Feb 02, 2017 at 04:40:49PM +0000, Will Deacon wrote:
> On Thu, Feb 02, 2017 at 06:30:28PM +0200, Michael S. Tsirkin wrote:
> > I am inclined to say, for 4.10 let's revert
> > c7070619f3408d9a0dffbed9149e6f00479cf43b since what it fixes is not a
> > regression in 4.10.
>
> No complaints there, as long as we can keep working to fix this for 4.11
> and
2017 Feb 09
3
[PATCH] virtio: Try to untangle DMA coherency
On Thu, Feb 02, 2017 at 04:40:49PM +0000, Will Deacon wrote:
> On Thu, Feb 02, 2017 at 06:30:28PM +0200, Michael S. Tsirkin wrote:
> > I am inclined to say, for 4.10 let's revert
> > c7070619f3408d9a0dffbed9149e6f00479cf43b since what it fixes is not a
> > regression in 4.10.
>
> No complaints there, as long as we can keep working to fix this for 4.11
> and