Re: [Resend Patch 1/3] Vmbus: Add function to report available ring buffer to write in total ring size percentage

[Martin K. Petersen]

Long,

> I hope this patch set goes through SCSI, because it's purpose is to
> improve storvsc.
>
> If this strategy is not possible, I can resubmit the 1st two patches to
> net, and the 3rd patch to scsi after the 1st two are merged.

Applied to my staging tree for 4.18/scsi-queue. Thanks!

-- 
Martin K. Petersen  Oracle Linux Engineering

RE: [Resend Patch 1/3] Vmbus: Add function to report available ring buffer to write in total ring size percentage

[Stephen Hemminger]

Maybe best through greg's char-misc tree since it has generic hv code and 
sometime updates both network and scsi.

Alternatively,  put common code through one tree, and hold off the network 
device change till next release.

-Original Message-
From: Long Li 
Sent: Wednesday, March 28, 2018 3:43 PM
To: Martin K. Petersen ; Long Li 

Cc: KY Srinivasan ; Haiyang Zhang ; 
Stephen Hemminger ; James E . J . Bottomley 
; de...@linuxdriverproject.org; 
linux-s...@vger.kernel.org; linux-ker...@vger.kernel.org; netdev@vger.kernel.org
Subject: RE: [Resend Patch 1/3] Vmbus: Add function to report available ring 
buffer to write in total ring size percentage

> Subject: Re: [Resend Patch 1/3] Vmbus: Add function to report available ring
> buffer to write in total ring size percentage
> 
> 
> Long,
> 
> > Netvsc has a function to calculate how much ring buffer in percentage
> > is available to write. This function is also useful for storvsc and
> > other vmbus devices.
> 
> What is the submission strategy for this series? Do you expect it to go
> through net or scsi? If the latter, I'll need an ack from davem.

Martin,

I hope this patch set goes through SCSI, because it's purpose is to improve 
storvsc.

If this strategy is not possible, I can resubmit the 1st two patches to net, 
and the 3rd patch to scsi after the 1st two are merged.

Long

> 
> --
> Martin K. PetersenOracle Linux Engineering

RE: [Resend Patch 1/3] Vmbus: Add function to report available ring buffer to write in total ring size percentage

[Long Li]

> Subject: Re: [Resend Patch 1/3] Vmbus: Add function to report available ring
> buffer to write in total ring size percentage
> 
> 
> Long,
> 
> > Netvsc has a function to calculate how much ring buffer in percentage
> > is available to write. This function is also useful for storvsc and
> > other vmbus devices.
> 
> What is the submission strategy for this series? Do you expect it to go
> through net or scsi? If the latter, I'll need an ack from davem.

Martin,

I hope this patch set goes through SCSI, because it's purpose is to improve 
storvsc.

If this strategy is not possible, I can resubmit the 1st two patches to net, 
and the 3rd patch to scsi after the 1st two are merged.

Long

> 
> --
> Martin K. PetersenOracle Linux Engineering

Re: [Resend Patch 1/3] Vmbus: Add function to report available ring buffer to write in total ring size percentage

[Martin K. Petersen]

Long,

> Netvsc has a function to calculate how much ring buffer in percentage is
> available to write. This function is also useful for storvsc and other
> vmbus devices.

What is the submission strategy for this series? Do you expect it to go
through net or scsi? If the latter, I'll need an ack from davem.

-- 
Martin K. Petersen  Oracle Linux Engineering

[Resend Patch 1/3] Vmbus: Add function to report available ring buffer to write in total ring size percentage

[Long Li]

From: Long Li 

Netvsc has a function to calculate how much ring buffer in percentage is
available to write. This function is also useful for storvsc and other
vmbus devices.

Define a similar function in vmbus to be used by other vmbus devices.

Signed-off-by: Long Li 
---
 drivers/hv/ring_buffer.c |  2 ++
 include/linux/hyperv.h   | 12 
 2 files changed, 14 insertions(+)

diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 8699bb969e7e..3c836c099a8f 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -227,6 +227,8 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info 
*ring_info,
ring_info->ring_buffer->feature_bits.value = 1;
 
ring_info->ring_size = page_cnt << PAGE_SHIFT;
+   ring_info->ring_size_div10_reciprocal =
+   reciprocal_value(ring_info->ring_size / 10);
ring_info->ring_datasize = ring_info->ring_size -
sizeof(struct hv_ring_buffer);
 
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 2048f3c3b68a..eb7204851089 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -36,6 +36,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #define MAX_PAGE_BUFFER_COUNT  32
 #define MAX_MULTIPAGE_BUFFER_COUNT 32 /* 128K */
@@ -121,6 +122,7 @@ struct hv_ring_buffer {
 struct hv_ring_buffer_info {
struct hv_ring_buffer *ring_buffer;
u32 ring_size;  /* Include the shared header */
+   struct reciprocal_value ring_size_div10_reciprocal;
spinlock_t ring_lock;
 
u32 ring_datasize;  /* < ring_size */
@@ -155,6 +157,16 @@ static inline u32 hv_get_bytes_to_write(const struct 
hv_ring_buffer_info *rbi)
return write;
 }
 
+static inline u32 hv_get_avail_to_write_percent(
+   const struct hv_ring_buffer_info *rbi)
+{
+   u32 avail_write = hv_get_bytes_to_write(rbi);
+
+   return reciprocal_divide(
+   (avail_write  << 3) + (avail_write << 1),
+   rbi->ring_size_div10_reciprocal);
+}
+
 /*
  * VMBUS version is 32 bit entity broken up into
  * two 16 bit quantities: major_number. minor_number.
-- 
2.14.1