Lines Matching +full:packet +full:- +full:processor

22 .TH PCAP-TSTAMP @MAN_MISC_INFO@ "14 July 2020"
24 pcap-tstamp \- packet time stamps in libpcap
26 When capturing traffic, each packet is given a time stamp representing,
27 for incoming packets, the arrival time of the packet and, for outgoing
28 packets, the transmission time of the packet.  This time is an
34 if the time stamp is applied to the packet when the networking stack
35 receives the packet, the networking stack might not see the packet until
36 an interrupt is delivered for the packet or a timer event causes the
38 not be applied until the packet has had some processing done by other
40 between the time when the last bit of the packet is received by the
41 capture device and when the networking stack time-stamps the packet;
48 a high-resolution timer might use a counter that runs at a rate
49 dependent on the processor clock speed, and that clock speed might be
58 different CPU cores on a multi-core or multi-processor system might be
60 synchronized, so packets time-stamped by different cores might not have
68 the fraction-of-a-second part of the time stamp might roll over past
72 For these reasons, time differences between packet time stamps will not
76 In addition, packets time-stamped by different cores might be
77 time-stamped in one order and added to the queue of packets for libpcap
82 packets; those time stamps are usually high-resolution time stamps, and
83 are usually applied to the packet when the first or last bit of the
84 packet arrives, and are thus more accurate than time stamps provided by
87 example, the time stamp of a packet might not correspond to the time
88 stamp of an event on the host triggered by the arrival of that packet.
96 routine provides, for a packet capture handle created by
125 This is a low-precision time stamp, synchronized with the host operating
130 This is a high-precision time stamp, synchronized with the host
136 This is a high-precision time stamp, not synchronized with the host
142 done.  This is a high-precision time stamp, synchronized with the host
147 done.  This is a high-precision time stamp; it is not synchronized with
157 Host-provided time stamps generally correspond to the time when the
158 time-stamping code sees the packet; this could be some unknown amount of
159 time after the first or last bit of the packet is received by the
160 network adapter, due to batching of interrupts for packet arrival,
165 and microseconds since that seconds value, even if higher-resolution
178 If the hardware or software cannot supply a higher-resolution time
191 the fraction-of-a-second portion of the time stamps will be scaled to