diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2017-03-06 22:21:35 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2017-05-09 16:43:21 +0300 |
| commit | e377fcc8486d40867c6c217077ad0fa40977e060 (patch) | |
| tree | aa80472501bb1f180165f6571559ec0a693dca44 /drivers | |
| parent | 680557cf79f82623e2c4fd42733077d60a843513 (diff) | |
virtio_net: reduce alignment for buffers
We don't need to align length to any particular
value anymore. Aligning to L1 cache size probably
sill makes sense to reduce false sharing.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/virtio_net.c | 13 |
1 files changed, 1 insertions, 12 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 2170a5caf68d..6e47e653a05d 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -53,17 +53,6 @@ module_param(gso, bool, 0444); */ DECLARE_EWMA(pkt_len, 0, 64) -/* With mergeable buffers we align buffer address and use the low bits to - * encode its true size. Buffer size is up to 1 page so we need to align to - * square root of page size to ensure we reserve enough bits to encode the true - * size. - */ -#define MERGEABLE_BUFFER_MIN_ALIGN_SHIFT ((PAGE_SHIFT + 1) / 2) - -/* Minimum alignment for mergeable packet buffers. */ -#define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, \ - 1 << MERGEABLE_BUFFER_MIN_ALIGN_SHIFT) - #define VIRTNET_DRIVER_VERSION "1.0.0" struct virtnet_stats { @@ -849,7 +838,7 @@ static unsigned int get_mergeable_buf_len(struct ewma_pkt_len *avg_pkt_len) len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len), GOOD_PACKET_LEN, PAGE_SIZE - hdr_len); - return ALIGN(len, MERGEABLE_BUFFER_ALIGN); + return ALIGN(len, L1_CACHE_BYTES); } static int add_recvbuf_mergeable(struct virtnet_info *vi, |