diff options
| author | Stephen Hemminger <stephen@networkplumber.org> | 2017-02-11 23:02:25 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-02-14 10:20:35 -0800 |
| commit | 8d12f88257cd9039d9556585475deb46db055050 (patch) | |
| tree | 6e4b09719c1c7f88285fdd80ed5ea342253bf4de /drivers/hv | |
| parent | e4165a0fad0963bf8b4a59f54d3360ccb6a6d1ea (diff) | |
| download | linux-8d12f88257cd9039d9556585475deb46db055050.tar.gz linux-8d12f88257cd9039d9556585475deb46db055050.tar.bz2 linux-8d12f88257cd9039d9556585475deb46db055050.zip | |
vmbus: replace modulus operation with subtraction
Takes less clock cycles to check for ring wrap and subtract than to
do a modulus instruction.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv')
| -rw-r--r-- | drivers/hv/ring_buffer.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 490e9ea098e6..87799e81af97 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -112,7 +112,8 @@ hv_get_next_readlocation_withoffset(const struct hv_ring_buffer_info *ring_info, u32 next = ring_info->ring_buffer->read_index; next += offset; - next %= ring_info->ring_datasize; + if (next >= ring_info->ring_datasize) + next -= ring_info->ring_datasize; return next; } @@ -156,7 +157,8 @@ static u32 hv_copyfrom_ringbuffer( memcpy(dest, ring_buffer + start_read_offset, destlen); start_read_offset += destlen; - start_read_offset %= ring_buffer_size; + if (start_read_offset >= ring_buffer_size) + start_read_offset -= ring_buffer_size; return start_read_offset; } @@ -178,7 +180,8 @@ static u32 hv_copyto_ringbuffer( memcpy(ring_buffer + start_write_offset, src, srclen); start_write_offset += srclen; - start_write_offset %= ring_buffer_size; + if (start_write_offset >= ring_buffer_size) + start_write_offset -= ring_buffer_size; return start_write_offset; } |