Drivers: hv: Implement routines for read side signaling optimization (6fdf3b21) · Commits · 戴 / test

Implement functions that will support read-side signaling optimization. By having the reader indicate the start of the "read" operation and the "end" of the read operation we can more efficiently handle the signaling protocol: while the read is in progress, there is no need for the "writer" to signal the "reader" as new items are put on the read queue. Signed-off-by:

K. Y. Srinivasan <kys@microsoft.com> Reviewed-by:

Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hv/hyperv_vmbus.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -570,6 +570,10 @@ u32 hv_get_ringbuffer_interrupt_mask(struct hv_ring_buffer_info *ring_info);
		void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info,
		struct hv_ring_buffer_debug_info *debug_info);

		void hv_begin_read(struct hv_ring_buffer_info *rbi);

		u32 hv_end_read(struct hv_ring_buffer_info *rbi);

		/*
		* Maximum channels is determined by the size of the interrupt page
		* which is PAGE_SIZE. 1/2 of PAGE_SIZE is for send endpoint interrupt

drivers/hv/ring_buffer.c

+24 −0

Original line number	Diff line number	Diff line
		@@ -29,6 +29,30 @@

		#include "hyperv_vmbus.h"

		void hv_begin_read(struct hv_ring_buffer_info *rbi)
		{
		rbi->ring_buffer->interrupt_mask = 1;
		smp_mb();
		}

		u32 hv_end_read(struct hv_ring_buffer_info *rbi)
		{
		u32 read;
		u32 write;

		rbi->ring_buffer->interrupt_mask = 0;
		smp_mb();

		/*
		* Now check to see if the ring buffer is still empty.
		* If it is not, we raced and we need to process new
		* incoming messages.
		*/
		hv_get_ringbuffer_availbytes(rbi, &read, &write);

		return read;
		}


		/*
		* hv_get_next_write_location()

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