Author: sephe Date: Mon Jan 25 05:33:18 2016 New Revision: 294705 URL: https://svnweb.freebsd.org/changeset/base/294705
Log: hyperv/vmbus: Avoid extra copy of page information. The page information array could contain up to 32 elements (i.e. 512B). And on network side w/ TSO, 11+ (176B+) elements, i.e. ~44K TSO packet, in the page information array is quite common. This saves us some cpu cycles. Reviewed by: adrian, delphij Approved by: adrian (mentor) Sponsored by: Microsoft OSTC Differential Revision: https://reviews.freebsd.org/D4992 Modified: head/sys/dev/hyperv/vmbus/hv_channel.c Modified: head/sys/dev/hyperv/vmbus/hv_channel.c ============================================================================== --- head/sys/dev/hyperv/vmbus/hv_channel.c Mon Jan 25 05:28:19 2016 (r294704) +++ head/sys/dev/hyperv/vmbus/hv_channel.c Mon Jan 25 05:33:18 2016 (r294705) @@ -665,11 +665,11 @@ hv_vmbus_channel_send_packet_pagebuffer( { int ret = 0; - int i = 0; boolean_t need_sig; uint32_t packet_len; + uint32_t page_buflen; uint32_t packetLen_aligned; - hv_vmbus_sg_buffer_list buffer_list[3]; + hv_vmbus_sg_buffer_list buffer_list[4]; hv_vmbus_channel_packet_page_buffer desc; uint32_t descSize; uint64_t alignedData = 0; @@ -681,36 +681,33 @@ hv_vmbus_channel_send_packet_pagebuffer( * Adjust the size down since hv_vmbus_channel_packet_page_buffer * is the largest size we support */ - descSize = sizeof(hv_vmbus_channel_packet_page_buffer) - - ((HV_MAX_PAGE_BUFFER_COUNT - page_count) * - sizeof(hv_vmbus_page_buffer)); - packet_len = descSize + buffer_len; + descSize = __offsetof(hv_vmbus_channel_packet_page_buffer, range); + page_buflen = sizeof(hv_vmbus_page_buffer) * page_count; + packet_len = descSize + page_buflen + buffer_len; packetLen_aligned = HV_ALIGN_UP(packet_len, sizeof(uint64_t)); /* Setup the descriptor */ desc.type = HV_VMBUS_PACKET_TYPE_DATA_USING_GPA_DIRECT; desc.flags = HV_VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; - desc.data_offset8 = descSize >> 3; /* in 8-bytes granularity */ + /* in 8-bytes granularity */ + desc.data_offset8 = (descSize + page_buflen) >> 3; desc.length8 = (uint16_t) (packetLen_aligned >> 3); desc.transaction_id = request_id; desc.range_count = page_count; - for (i = 0; i < page_count; i++) { - desc.range[i].length = page_buffers[i].length; - desc.range[i].offset = page_buffers[i].offset; - desc.range[i].pfn = page_buffers[i].pfn; - } - buffer_list[0].data = &desc; buffer_list[0].length = descSize; - buffer_list[1].data = buffer; - buffer_list[1].length = buffer_len; + buffer_list[1].data = page_buffers; + buffer_list[1].length = page_buflen; - buffer_list[2].data = &alignedData; - buffer_list[2].length = packetLen_aligned - packet_len; + buffer_list[2].data = buffer; + buffer_list[2].length = buffer_len; - ret = hv_ring_buffer_write(&channel->outbound, buffer_list, 3, + buffer_list[3].data = &alignedData; + buffer_list[3].length = packetLen_aligned - packet_len; + + ret = hv_ring_buffer_write(&channel->outbound, buffer_list, 4, &need_sig); /* TODO: We should determine if this is optional */ _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
