This is a note to let you know that I've just added the patch titled
vmbus: eliminate duplicate cached index
to the 4.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
vmbus-eliminate-duplicate-cached-index.patch
and it can be found in the queue-4.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 05d00bc94ac27d220d8a78e365d7fa3a26dcca17 Mon Sep 17 00:00:00 2001
From: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
Date: Sun, 25 Jun 2017 12:30:27 -0700
Subject: vmbus: eliminate duplicate cached index
From: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
commit 05d00bc94ac27d220d8a78e365d7fa3a26dcca17 upstream.
Don't need cached read index anymore now that packet iterator
is used. The iterator has the original read index until the
visible read_index is updated.
Signed-off-by: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/hv/ring_buffer.c | 17 ++++-------------
include/linux/hyperv.h | 14 --------------
2 files changed, 4 insertions(+), 27 deletions(-)
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -358,9 +358,6 @@ struct vmpacket_descriptor *hv_pkt_iter_
{
struct hv_ring_buffer_info *rbi = &channel->inbound;
- /* set state for later hv_pkt_iter_close */
- rbi->cached_read_index = rbi->ring_buffer->read_index;
-
if (hv_pkt_iter_avail(rbi) < sizeof(struct vmpacket_descriptor))
return NULL;
@@ -388,10 +385,7 @@ __hv_pkt_iter_next(struct vmbus_channel
rbi->priv_read_index -= dsize;
/* more data? */
- if (hv_pkt_iter_avail(rbi) < sizeof(struct vmpacket_descriptor))
- return NULL;
- else
- return hv_get_ring_buffer(rbi) + rbi->priv_read_index;
+ return hv_pkt_iter_first(channel);
}
EXPORT_SYMBOL_GPL(__hv_pkt_iter_next);
@@ -401,7 +395,7 @@ EXPORT_SYMBOL_GPL(__hv_pkt_iter_next);
void hv_pkt_iter_close(struct vmbus_channel *channel)
{
struct hv_ring_buffer_info *rbi = &channel->inbound;
- u32 cur_write_sz, cached_write_sz;
+ u32 orig_write_sz = hv_get_bytes_to_write(rbi);
u32 pending_sz;
/*
@@ -430,13 +424,10 @@ void hv_pkt_iter_close(struct vmbus_chan
if (pending_sz == 0)
return;
- cur_write_sz = hv_get_bytes_to_write(rbi);
-
- if (cur_write_sz < pending_sz)
+ if (hv_get_bytes_to_write(rbi) < pending_sz)
return;
- cached_write_sz = hv_get_cached_bytes_to_write(rbi);
- if (cached_write_sz < pending_sz)
+ if (orig_write_sz < pending_sz)
vmbus_setevent(channel);
}
EXPORT_SYMBOL_GPL(hv_pkt_iter_close);
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -127,7 +127,6 @@ struct hv_ring_buffer_info {
u32 ring_data_startoffset;
u32 priv_write_index;
u32 priv_read_index;
- u32 cached_read_index;
};
/*
@@ -180,19 +179,6 @@ static inline u32 hv_get_bytes_to_write(
return write;
}
-static inline u32 hv_get_cached_bytes_to_write(
- const struct hv_ring_buffer_info *rbi)
-{
- u32 read_loc, write_loc, dsize, write;
-
- dsize = rbi->ring_datasize;
- read_loc = rbi->cached_read_index;
- write_loc = rbi->ring_buffer->write_index;
-
- write = write_loc >= read_loc ? dsize - (write_loc - read_loc) :
- read_loc - write_loc;
- return write;
-}
/*
* VMBUS version is 32 bit entity broken up into
* two 16 bit quantities: major_number. minor_number.
Patches currently in stable-queue which might be from stephen@xxxxxxxxxxxxxxxxxx are
queue-4.13/vmbus-more-host-signalling-avoidance.patch
queue-4.13/vmbus-refactor-hv_signal_on_read.patch
queue-4.13/vmbus-simplify-hv_ringbuffer_read.patch
queue-4.13/vmbus-eliminate-duplicate-cached-index.patch