Differential D32693 Diff 97546 sys/netinet/cc/cc_dctcp.c

Changeset View

Standalone View

sys/netinet/cc/cc_dctcp.c

Show First 20 Lines • Show All 70 Lines • ▼ Show 20 Lines	struct dctcp {
int alpha; /* the fraction of marked bytes */		int alpha; /* the fraction of marked bytes */
int ce_prev; /* CE state of the last segment */		int ce_prev; /* CE state of the last segment */
tcp_seq save_sndnxt; /* end sequence number of the current window */		tcp_seq save_sndnxt; /* end sequence number of the current window */
int ece_curr; /* ECE flag in this segment */		int ece_curr; /* ECE flag in this segment */
int ece_prev; /* ECE flag in the last segment */		int ece_prev; /* ECE flag in the last segment */
uint32_t num_cong_events; /* # of congestion events */		uint32_t num_cong_events; /* # of congestion events */
};		};

static MALLOC_DEFINE(M_dctcp, "dctcp data",
"Per connection data required for the dctcp algorithm");

static void dctcp_ack_received(struct cc_var *ccv, uint16_t type);		static void dctcp_ack_received(struct cc_var *ccv, uint16_t type);
static void dctcp_after_idle(struct cc_var *ccv);		static void dctcp_after_idle(struct cc_var *ccv);
static void dctcp_cb_destroy(struct cc_var *ccv);		static void dctcp_cb_destroy(struct cc_var *ccv);
static int dctcp_cb_init(struct cc_var *ccv);		static int dctcp_cb_init(struct cc_var ccv, void ptr);
static void dctcp_cong_signal(struct cc_var *ccv, uint32_t type);		static void dctcp_cong_signal(struct cc_var *ccv, uint32_t type);
static void dctcp_conn_init(struct cc_var *ccv);		static void dctcp_conn_init(struct cc_var *ccv);
static void dctcp_post_recovery(struct cc_var *ccv);		static void dctcp_post_recovery(struct cc_var *ccv);
static void dctcp_ecnpkt_handler(struct cc_var *ccv);		static void dctcp_ecnpkt_handler(struct cc_var *ccv);
static void dctcp_update_alpha(struct cc_var *ccv);		static void dctcp_update_alpha(struct cc_var *ccv);
		static size_t dctcp_data_sz(void);

struct cc_algo dctcp_cc_algo = {		struct cc_algo dctcp_cc_algo = {
.name = "dctcp",		.name = "dctcp",
.ack_received = dctcp_ack_received,		.ack_received = dctcp_ack_received,
.cb_destroy = dctcp_cb_destroy,		.cb_destroy = dctcp_cb_destroy,
.cb_init = dctcp_cb_init,		.cb_init = dctcp_cb_init,
.cong_signal = dctcp_cong_signal,		.cong_signal = dctcp_cong_signal,
.conn_init = dctcp_conn_init,		.conn_init = dctcp_conn_init,
.post_recovery = dctcp_post_recovery,		.post_recovery = dctcp_post_recovery,
.ecnpkt_handler = dctcp_ecnpkt_handler,		.ecnpkt_handler = dctcp_ecnpkt_handler,
.after_idle = dctcp_after_idle,		.after_idle = dctcp_after_idle,
		.cc_data_sz = dctcp_data_sz,
};		};

static void		static void
dctcp_ack_received(struct cc_var *ccv, uint16_t type)		dctcp_ack_received(struct cc_var *ccv, uint16_t type)
{		{
struct dctcp *dctcp_data;		struct dctcp *dctcp_data;
int bytes_acked = 0;		int bytes_acked = 0;

dctcp_data = ccv->cc_data;		dctcp_data = ccv->cc_data;

if (CCV(ccv, t_flags2) & TF2_ECN_PERMIT) {		if (CCV(ccv, t_flags2) & TF2_ECN_PERMIT) {
/*		/*
* DCTCP doesn't treat receipt of ECN marked packet as a		* DCTCP doesn't treat receipt of ECN marked packet as a
* congestion event. Thus, DCTCP always executes the ACK		* congestion event. Thus, DCTCP always executes the ACK
* processing out of congestion recovery.		* processing out of congestion recovery.
*/		*/
if (IN_CONGRECOVERY(CCV(ccv, t_flags))) {		if (IN_CONGRECOVERY(CCV(ccv, t_flags))) {
EXIT_CONGRECOVERY(CCV(ccv, t_flags));		EXIT_CONGRECOVERY(CCV(ccv, t_flags));
newreno_cc_algo.ack_received(ccv, type);		common_cc_ack_received(ccv, type);
ENTER_CONGRECOVERY(CCV(ccv, t_flags));		ENTER_CONGRECOVERY(CCV(ccv, t_flags));
} else		} else
newreno_cc_algo.ack_received(ccv, type);		common_cc_ack_received(ccv, type);

if (type == CC_DUPACK)		if (type == CC_DUPACK)
bytes_acked = min(ccv->bytes_this_ack, CCV(ccv, t_maxseg));		bytes_acked = min(ccv->bytes_this_ack, CCV(ccv, t_maxseg));

if (type == CC_ACK)		if (type == CC_ACK)
bytes_acked = ccv->bytes_this_ack;		bytes_acked = ccv->bytes_this_ack;

/* Update total bytes. */		/* Update total bytes. */
Show All 21 Lines	if (CCV(ccv, t_flags2) & TF2_ECN_PERMIT) {
/*		/*
* Update the fraction of marked bytes at the end of		* Update the fraction of marked bytes at the end of
* current window size.		* current window size.
*/		*/
if (!IN_FASTRECOVERY(CCV(ccv, t_flags)) &&		if (!IN_FASTRECOVERY(CCV(ccv, t_flags)) &&
SEQ_GT(ccv->curack, dctcp_data->save_sndnxt))		SEQ_GT(ccv->curack, dctcp_data->save_sndnxt))
dctcp_update_alpha(ccv);		dctcp_update_alpha(ccv);
} else		} else
newreno_cc_algo.ack_received(ccv, type);		common_cc_ack_received(ccv, type);
}		}

		static size_t
		dctcp_data_sz(void)
		{
		return (sizeof(struct dctcp));
		}

static void		static void
dctcp_after_idle(struct cc_var *ccv)		dctcp_after_idle(struct cc_var *ccv)
{		{
struct dctcp *dctcp_data;		struct dctcp *dctcp_data;

if (CCV(ccv, t_flags2) & TF2_ECN_PERMIT) {		if (CCV(ccv, t_flags2) & TF2_ECN_PERMIT) {
dctcp_data = ccv->cc_data;		dctcp_data = ccv->cc_data;

/* Initialize internal parameters after idle time */		/* Initialize internal parameters after idle time */
dctcp_data->bytes_ecn = 0;		dctcp_data->bytes_ecn = 0;
dctcp_data->bytes_total = 0;		dctcp_data->bytes_total = 0;
dctcp_data->save_sndnxt = CCV(ccv, snd_nxt);		dctcp_data->save_sndnxt = CCV(ccv, snd_nxt);
dctcp_data->alpha = V_dctcp_alpha;		dctcp_data->alpha = V_dctcp_alpha;
dctcp_data->ece_curr = 0;		dctcp_data->ece_curr = 0;
dctcp_data->ece_prev = 0;		dctcp_data->ece_prev = 0;
dctcp_data->num_cong_events = 0;		dctcp_data->num_cong_events = 0;
}		}

newreno_cc_algo.after_idle(ccv);		common_cc_after_idle(ccv);
}		}

static void		static void
dctcp_cb_destroy(struct cc_var *ccv)		dctcp_cb_destroy(struct cc_var *ccv)
{		{
free(ccv->cc_data, M_dctcp);		free(ccv->cc_data, M_CC_MEM);
}		}

static int		static int
dctcp_cb_init(struct cc_var *ccv)		dctcp_cb_init(struct cc_var ccv, void ptr)
{		{
struct dctcp *dctcp_data;		struct dctcp *dctcp_data;

dctcp_data = malloc(sizeof(struct dctcp), M_dctcp, M_NOWAIT\|M_ZERO);		if (ptr == NULL) {
		dctcp_data = malloc(sizeof(struct dctcp), M_CC_MEM, M_NOWAIT\|M_ZERO);
if (dctcp_data == NULL)		if (dctcp_data == NULL)
return (ENOMEM);		return (ENOMEM);
		} else
		dctcp_data = ptr;
/* Initialize some key variables with sensible defaults. */		/* Initialize some key variables with sensible defaults. */
dctcp_data->bytes_ecn = 0;		dctcp_data->bytes_ecn = 0;
dctcp_data->bytes_total = 0;		dctcp_data->bytes_total = 0;
/*		/*
* When alpha is set to 0 in the beginning, DCTCP sender transfers as		* When alpha is set to 0 in the beginning, DCTCP sender transfers as
* much data as possible until the value converges which may expand the		* much data as possible until the value converges which may expand the
* queueing delay at the switch. When alpha is set to 1, queueing delay		* queueing delay at the switch. When alpha is set to 1, queueing delay
* is kept small.		* is kept small.
▲ Show 20 Lines • Show All 78 Lines • ▼ Show 20 Lines	case CC_RTO:
2) * mss;		2) * mss;
CCV(ccv, snd_cwnd) = mss;		CCV(ccv, snd_cwnd) = mss;
dctcp_update_alpha(ccv);		dctcp_update_alpha(ccv);
dctcp_data->save_sndnxt += CCV(ccv, t_maxseg);		dctcp_data->save_sndnxt += CCV(ccv, t_maxseg);
dctcp_data->num_cong_events++;		dctcp_data->num_cong_events++;
break;		break;
}		}
} else		} else
newreno_cc_algo.cong_signal(ccv, type);		common_cc_cong_signal(ccv, type);
}		}

static void		static void
dctcp_conn_init(struct cc_var *ccv)		dctcp_conn_init(struct cc_var *ccv)
{		{
struct dctcp *dctcp_data;		struct dctcp *dctcp_data;

dctcp_data = ccv->cc_data;		dctcp_data = ccv->cc_data;

if (CCV(ccv, t_flags2) & TF2_ECN_PERMIT)		if (CCV(ccv, t_flags2) & TF2_ECN_PERMIT)
dctcp_data->save_sndnxt = CCV(ccv, snd_nxt);		dctcp_data->save_sndnxt = CCV(ccv, snd_nxt);
}		}

/*		/*
* Perform any necessary tasks before we exit congestion recovery.		* Perform any necessary tasks before we exit congestion recovery.
*/		*/
static void		static void
dctcp_post_recovery(struct cc_var *ccv)		dctcp_post_recovery(struct cc_var *ccv)
{		{
newreno_cc_algo.post_recovery(ccv);		common_cc_post_recovery(ccv);

if (CCV(ccv, t_flags2) & TF2_ECN_PERMIT)		if (CCV(ccv, t_flags2) & TF2_ECN_PERMIT)
dctcp_update_alpha(ccv);		dctcp_update_alpha(ccv);
}		}

/*		/*
* Execute an additional ECN processing using ECN field in IP header		* Execute an additional ECN processing using ECN field in IP header
* and the CWR bit in TCP header.		* and the CWR bit in TCP header.
▲ Show 20 Lines • Show All 148 Lines • Show Last 20 Lines