JP5278157B2 - Transmission apparatus and transmission method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmitter and a transmission method for preventing a depletion of a receiving buffer. <P>SOLUTION: The transmission method includes the steps of: periodically calculating a usage rate of a buffer memory; accumulating the calculated usage rate in a volatile memory; calculating a predicted usage rate based on the accumulated usage rate; adding the receiving buffer to a buffer pool, when the calculated predicted usage rate is larger than a risk threshold; and deleting the added receiving buffer from the buffer memory, when the predicted usage rate is smaller than a predetermined safety threshold. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a transmission apparatus and a transmission method.

  Conventionally, for example, in a system using a network protocol such as TCP / IP (Transmission Control Protocol / Internet Protocol), a transmission device that transmits a packet received from an arbitrary device to another destination device is used.

  Such a transmission apparatus has a buffer memory for storing received packets, and each time a packet is received, the received packet is stored in the buffer memory and the received packet is transmitted to the transmission destination apparatus. Then, when the transmission apparatus receives a notification that the reception of the packet is completed from the transmission destination apparatus, the transmission apparatus releases the buffer memory in which the packet is stored.

  Here, a buffer memory management method by a conventional transmission apparatus will be described with reference to FIGS. 17 and 18. 17 and 18 are diagrams illustrating a configuration example of a conventional transmission apparatus. As illustrated in FIG. 17, the conventional transmission apparatus 910 includes a buffer pool 911, an Ether HD (Ethernet (registered trademark) Hard) 912, an Ether driver 913, a network driver 914, and a network protocol 915.

  The buffer pool 911 is a buffer memory having a plurality of reception buffers. In the example illustrated in FIG. 17, the buffer pool 911 includes a plurality of reception buffers having a size of 2048 [Bytes]. Such a configuration of the buffer pool 911 is determined by the transmission apparatus 910 when the system is started. For example, in the example illustrated in FIG. 17, the transmission apparatus 910 constructs the buffer pool 911 by generating 3000 reception buffers of 2048 [Byte] at the time of activation.

  In the example illustrated in FIG. 17, the Ether HD 912 receives a packet from an external device. The Ether driver 913 activates the network driver 914 and transmits the received packet to the network driver 914 when the packet is received by the Ether HD 912. The network driver 914 captures the reception buffer from the buffer pool 911 and stores the reception packet in the captured reception buffer. Then, the network driver 914 notifies the network protocol 915 of the reception buffer storing the received packet. The network protocol 915 performs transmission processing according to a predetermined communication standard.

  Next, the conventional transmission apparatus 920 shown in FIG. 18 will be described. Here, parts having the same functions as the constituent parts shown in FIG. 17 are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in FIG. 18, the conventional transmission apparatus 920 has a buffer pool 921.

  In the example shown in FIG. 18, the buffer pool 921 has a plurality of types of reception buffers having different sizes. Specifically, the buffer pool 921 includes a reception buffer having a size of 2048 [Bytes], a reception buffer having a size of 1024 [Bytes], and a reception buffer having a size of 512 [Bytes]. That is, the conventional transmission apparatus 920 shown in FIG. 18 constructs a buffer pool 921 by generating reception buffers of 2048 [Byte], 1024 [Byte], and 512 [Byte] at the time of activation.

  Under such a configuration, if the size of the received packet is 512 [Bytes] or less, the network driver 924 illustrated in FIG. 18 stores the received packet in the 512 [Byte] reception buffer. Also, if the size of the received packet is larger than 512 [Bytes] and smaller than 1024 [Bytes], the network driver 924 stores the received packet in the 1024 [Byte] reception buffer. In addition, if the size of the received packet is larger than 1024 [Bytes] and equal to or smaller than 2048 [Bytes], the network driver 924 stores the received packet in the 2048 [Byte] reception buffer.

  In recent years, a technique has been known in which statistical data of a received packet size is calculated, and the number of reception buffers is dynamically changed in a buffer memory area generated at startup based on the calculated statistical data.

JP 2005-84179 A JP-A-8-65353 Japanese Unexamined Patent Publication No. 63-158941

  However, the above-described conventional technique has a problem that the reception buffer may be exhausted. Specifically, when the buffer pool 921 is constructed with the same size reception buffer as in the transmission apparatus 910 shown in FIG. 17, when a packet with a small size bursts, the memory capacity is not limited. The receive buffer may be exhausted.

  For example, it is assumed that the transmission apparatus 910 illustrated in FIG. 17 has 3000 reception buffers of 2048 [Bytes]. In such a state, when the transmission apparatus 910 receives a 10 [Byte] packet, the transmission apparatus 910 stores the received packet in a 2048 [Byte] reception buffer. At this time, the memory area of 2038 [Byte] in the reception buffer storing the reception packet becomes an unused area. That is, in the above example, if the transmission apparatus 910 receives 3000 packets of 10 [Bytes] continuously, for example, all the reception buffers are used, and therefore the reception buffers are exhausted.

  In addition, when a plurality of types of reception buffers are used as in the transmission device 920 illustrated in FIG. 18, the buffer memory is used efficiently, so that it is unlikely that the reception buffer is exhausted as compared with the example illustrated in FIG. 17. Conceivable. However, it is difficult to predict the optimum number of reception buffers because the size of a burst of packets that changes dynamically changes every moment. That is, the number of reception buffers at system startup is not always optimal. For this reason, even if the transmission apparatus 920 shown in FIG. 18 is used, the reception buffer may be exhausted.

  In addition, when the above-described technique for dynamically changing the number of reception buffers is used, when a plurality of types of packets having different sizes burst at the same time, the reception buffers may be exhausted. For example, in the case of having reception buffers of 2048 [Byte], 1024 [Byte], and 512 [Byte], it is assumed that a plurality of types of packets burst simultaneously. In such a case, even if the reception buffer is reconstructed using the conventional technique, the problem that the reception buffer is exhausted cannot be solved.

  The disclosed technology has been made in view of the above, and an object thereof is to provide a transmission apparatus and a transmission method that can prevent the reception buffer from being exhausted.

Transmission device disclosed in the application, in one embodiment, a buffer memory having a plurality of receive buffers of a plurality of types having different sizes for storing the received packet, the type of the receive buffer utilization of the buffer memory each time it receives a packet A calculation unit that calculates each time, and a fluctuation amount of the usage rate of the buffer memory is calculated based on the usage rate calculated by the calculation unit every time a predetermined monitoring period elapses, and based on the calculated fluctuation amount there are prediction unit and the type of the predicted predicted usage reception is greater than the predetermined danger threshold buffer by the prediction unit for predicting predicted utilization is utilization of future for each type of the reception buffer in the buffer memory Te when a memory management unit for adding the receive buffer size corresponding to the type of the receiving buffer in the buffer memory Wherein the calculation unit, when the rate of increase in utilization of the buffer memory is larger than the predetermined increase rate threshold, set the short-term increase flag indicating that short term usage increases, the prediction unit When the short-term increase flag is set by the calculation unit and there is a reception buffer type whose predicted usage rate predicted by the prediction unit is smaller than a predetermined safety threshold, the size corresponding to the reception buffer type A part of the reception buffer is deleted from the buffer memory .

  According to one aspect of the transmission device disclosed in the present application, it is possible to prevent the reception buffer from being exhausted.

FIG. 1 is a diagram for explaining a situation where the usage rate increases rapidly. FIG. 2 is a diagram for explaining a situation where the usage rate gradually increases. FIG. 3 is a diagram illustrating a configuration example of the transmission apparatus according to the first embodiment. FIG. 4 is a diagram illustrating an example of monitoring data. FIG. 5 is a diagram illustrating an example of monitoring cycle data and an increase flag. FIG. 6 is a diagram illustrating an example of the optimum pattern data. FIG. 7 is a diagram illustrating a configuration example of the transmission apparatus at the time of activation. FIG. 8 is a flowchart illustrating the packet reception processing procedure performed by the transmission apparatus according to the first embodiment. FIG. 9 is a flowchart illustrating a scheduling processing procedure by the scheduling unit according to the first embodiment. FIG. 10 is a flowchart illustrating a buffer pool control processing procedure by the buffer pool control unit according to the first embodiment. FIG. 11 is a flowchart illustrating a short-term pattern calculation processing procedure by the optimum buffer pattern prediction unit according to the first embodiment. FIG. 12 is a flowchart illustrating a long-term pattern calculation processing procedure by the optimum buffer pattern prediction unit according to the first embodiment. FIG. 13 is a flowchart illustrating the additional prediction processing procedure performed by the optimum buffer pattern prediction unit according to the first embodiment. FIG. 14 is a flowchart illustrating a deletion prediction processing procedure by the optimum buffer pattern prediction unit according to the first embodiment. FIG. 15 is a flowchart illustrating the activation processing procedure performed by the transmission apparatus according to the first embodiment. FIG. 16 is a flowchart showing a short-term pattern calculation processing procedure by the optimum buffer pattern prediction unit when the addition process and the deletion process are performed simultaneously. FIG. 17 is a diagram illustrating a configuration example of a conventional transmission apparatus. FIG. 18 is a diagram illustrating a configuration example of a conventional transmission apparatus.

  Hereinafter, embodiments of a transmission device and a transmission method disclosed in the present application will be described in detail with reference to the drawings. The transmission apparatus and the transmission method disclosed in the present application are not limited by this embodiment. The transmission apparatus shown in the following embodiments can be applied to, for example, a base station or a router.

  First, the transmission apparatus 100 according to the first embodiment will be described. The transmission apparatus 100 according to the first embodiment calculates the buffer memory usage rate each time a packet is received. Then, every time a predetermined monitoring period elapses, the transmission apparatus 100 calculates the fluctuation amount of the buffer memory usage rate based on the calculated usage rate, and predicts the future usage rate based on the calculated fluctuation amount. To do. Then, when the predicted usage rate is larger than the predetermined risk threshold, the transmission apparatus 100 secures a free area such as a heap area or a reserved area in the memory as a reception buffer, and adds the secured reception buffer to the buffer memory. . In addition, when the predicted usage rate is smaller than the predetermined safety threshold, the transmission device 100 deletes the added reception buffer from the buffer memory and releases it to the heap area or the reserved area.

  As a result, the transmission apparatus 100 according to the first embodiment can dynamically generate a reception buffer according to the reception status of packets that change every moment even during the operation of the system. As a result, the transmission apparatus 100 according to the first embodiment can prevent the reception buffer from being exhausted.

  Further, the transmission apparatus 100 according to the first embodiment varies the monitoring cycle described above according to the usage rate. Specifically, the transmission apparatus 100 sets the monitoring cycle to a smaller value as the highest usage rate (hereinafter referred to as “maximum usage rate”) among the usage rates corresponding to each type of reception buffer, and the maximum usage rate. The smaller the rate, the larger the monitoring period.

  For this reason, since the transmission apparatus 100 monitors the buffer pool with a short monitoring cycle when the usage rate is high, it can immediately cope with the depletion of the reception buffer. Moreover, since the transmission apparatus 100 monitors the buffer pool with a long monitoring cycle when the usage rate is low, the monitoring load can be reduced.

  Also, the transmission apparatus 100 according to the first embodiment determines whether or not the usage rate has increased rapidly in a short time, and determines whether or not to perform the reception buffer deletion process. Specifically, the transmission apparatus 100 deletes the reception buffer when the usage rate decreases after the reception buffer is added because the usage rate has rapidly increased. On the other hand, if the reception buffer is added because the usage rate has gradually increased over a long period of time, the transmission apparatus 100 does not delete the reception buffer thereafter.

  The reason for determining whether or not to perform the deletion process will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram for explaining a situation where the usage rate increases rapidly. FIG. 2 is a diagram for explaining a situation in which the usage rate gradually increases. 1 and 2, the vertical axis indicates the buffer memory usage rate, and the horizontal axis indicates the passage of time.

  In the example shown in FIG. 1, first, the usage rate increases rapidly in a short time. Thereafter, the usage rate gradually decreases and returns to a predetermined value. Such a situation can generally occur when an event such as a disaster or a festival is held. Therefore, when the usage rate increases rapidly in a short time as in the example shown in FIG. 1, the usage rate generally decreases gradually. Therefore, the transmission apparatus 100 according to the first embodiment adds a reception buffer to the buffer pool when the usage rate increases, as in the example illustrated in FIG. Sometimes delete the receive buffer from the buffer pool. In other words, the transmission apparatus 100 adds the reception buffer to the buffer pool only during a time period in which the reception buffer may be exhausted.

  On the other hand, in the example shown in FIG. 2, the usage rate increases moderately. Thereafter, the usage rate does not decrease and remains at a predetermined value. Such a situation can generally occur when the population increases. Therefore, as in the example shown in FIG. 2, when the usage rate gradually increases, generally, there is almost no case where the usage rate decreases thereafter. Therefore, as in the example illustrated in FIG. 2, the transmission apparatus 100 according to the first embodiment adds a reception buffer to the buffer pool when the usage rate increases when the usage rate gradually increases. The process of deleting is not performed.

  Hereinafter, the transmission apparatus 100 described above will be described in detail.

[Configuration of Transmission Apparatus According to First Embodiment]
Next, the configuration of the transmission apparatus 100 according to the first embodiment will be described with reference to FIG. FIG. 3 is a diagram illustrating a configuration example of the transmission apparatus 100 according to the first embodiment. As illustrated in FIG. 3, the transmission apparatus 100 includes an Ether HD 111, an Ether driver 112, a network driver 120, a network protocol 130, a buffer pool 140, a usage rate calculation unit 150, a volatile memory 160, and a CPU 171. A non-volatile memory 173, a Timer 172, an OS 180, a buffer pool control unit 191, and an optimum buffer pattern prediction unit 192.

  The Ether HD 111 is an interface that receives a packet from an external device. The Ether driver 112 activates the network driver 120 when a packet is received by the Ether HD 111 and transmits the received packet to the network driver 120.

  The network driver 120 captures the reception buffer from the buffer pool 140, stores the received packet received from the Ether driver 112 in the captured reception buffer, and activates the usage rate calculation unit 150. At this time, the network driver 120 determines a reception buffer to be captured based on the size of the reception packet. For example, when the network driver 120 receives a 1800 [Byte] packet, the network driver 120 captures a 2048 [Byte] reception buffer and stores the received packet in the captured reception buffer.

  Further, the network driver 120 notifies the network protocol 130 of the reception buffer storing the received packet. The network protocol 130 performs transmission processing according to a predetermined communication standard.

  The buffer pool 140 has a plurality of types of reception buffers having different sizes. In the example illustrated in FIG. 3, the buffer pool 140 includes a reception buffer having a size of 2048 [Bytes], a reception buffer having a size of 1024 [Bytes], and a reception buffer having a size of 512 [Bytes]. .

  Although not shown in FIG. 3, the transmission apparatus 100 includes a memory used for a heap area, a reserved area, and the like in addition to the buffer pool 140. Such heap area and reserve area are areas allocated by a compiler and a linker, and are mainly used when a program dynamically requests a variable-length memory area. That is, the heap area and the reserved area are free areas that are freely secured by programs such as an OS (Operating System) and application software.

  The usage rate calculation unit 150 calculates the usage rate, the monitoring cycle, and the like of the buffer pool 140 each time a received packet is stored in the buffer pool 140 by the network driver 120. Hereinafter, the processing of the usage rate calculation unit 150 will be specifically described.

  The usage rate calculation unit 150 divides the number of reception buffers storing reception packets by the total number of reception buffers for each type of reception buffer every time reception packets are stored in the buffer pool 140. Calculate the usage rate of the receive buffer.

  For example, it is assumed that the buffer pool 140 has 100 reception buffers of 2048 [Bytes]. In addition, it is assumed that reception packets are stored in 20 reception buffers of 2048 [Byte] reception buffers. In this case, the usage rate calculation unit 150 divides the number of reception buffers “20” in which received packets are stored by the total number of reception buffers “100”, thereby obtaining the usage rate of the reception buffer of 2048 [Bytes]. , “20%” is calculated. Similarly, the usage rate calculation unit 150 calculates the usage rate for the reception buffers of 1024 [Byte] and 512 [Byte].

  Then, the usage rate calculation unit 150 stores the calculated usage rate in the volatile memory 160. At this time, the usage rate calculation unit 150 stores the usage rate in the volatile memory 160 for each type of reception buffer in association with the time when the packet is received. Hereinafter, the usage rate information stored in the volatile memory 160 by the usage rate calculation unit 150 is referred to as “monitoring data”.

  In addition, after calculating the usage rate, the usage rate calculation unit 150 extracts the maximum usage rate from each usage rate calculated for each type of reception buffer, and determines a monitoring cycle based on the extracted maximum usage rate. Specifically, the usage rate calculation unit 150 determines that the monitoring cycle is set to a smaller value as the maximum usage rate is higher, and the monitoring cycle is set to a higher value as the maximum usage rate is lower. It is stored in the memory 173. Hereinafter, the monitoring period stored in the nonvolatile memory 173 by the usage rate calculation unit 150 is referred to as “monitoring period data”.

  For example, when the maximum usage rate is “30%”, the usage rate calculation unit 150 determines the monitoring cycle to be “6 hours”, and when the maximum usage rate is “50%”, the monitoring cycle is set to “1 hour”. When the maximum usage rate is “90%”, the monitoring cycle is determined to be “3 minutes”. Here, the usage rate of the reception buffer of 2048 [Byte] is “30%”, the usage rate of the reception buffer of 1024 [Byte] is “90%”, and the usage rate of the reception buffer of 512 [Byte] is used. It is assumed that the rate is “10%”.

  In such a case, the usage rate calculation unit 150 extracts “90%” as the maximum usage rate. Then, since the extracted maximum usage rate is “90%”, the usage rate calculation unit 150 determines to set the monitoring cycle to “3 minutes”.

  In addition, after calculating the usage rate, the usage rate calculation unit 150 calculates an increase rate of the usage rate for each type of reception buffer. Subsequently, the usage rate calculation unit 150 extracts the highest increase rate (hereinafter, referred to as “maximum increase rate”) from each increase rate calculated for each type of reception buffer. Then, when the extracted maximum increase rate is larger than a predetermined increase rate threshold, the usage rate calculation unit 150 stores a short-term increase flag indicating that the usage rate has increased in a short time in the nonvolatile memory 173. On the other hand, when the maximum increase rate is equal to or less than the increase rate threshold, the usage rate calculation unit 150 stores a long-term increase flag indicating that the usage rate has gradually increased over a long period of time in the nonvolatile memory 173. Hereinafter, the long-term increase flag or the short-term increase flag stored in the nonvolatile memory 173 by the usage rate calculation unit 150 is referred to as an “increase flag”.

  The volatile memory 160 stores the monitoring data described above. FIG. 4 shows an example of the monitoring data. As shown in FIG. 4, the monitoring data stores the usage rate for each type of reception buffer in association with the time when the packet is received.

  In the example shown in FIG. 4, at the time “10:00:00”, the usage rates of the reception buffers of 2048 [Byte], 1024 [Byte], and 512 [Byte] are all “10%”. Show. In the example shown in FIG. 4, at the time “10:10:00”, the usage rates of the reception buffers of 2048 [Byte], 1024 [Byte], and 512 [Byte] are “70%”, “ 30% "and" 10% ".

  A CPU (Central Processing Unit) 171 controls the transmission apparatus 100 as a whole, and controls, for example, each unit such as the usage rate calculation unit 150 and the OS 180. The Timer 172 issues a timer interrupt to the OS 180 described later.

  The nonvolatile memory 173 stores monitoring cycle data, an increase flag, optimum pattern data, and the like. Specifically, in the nonvolatile memory 173, the monitoring period data and the increase flag are stored by the usage rate calculation unit 150.

  FIG. 5 shows an example of monitoring cycle data and an increase flag stored in the nonvolatile memory 173. In the example illustrated in FIG. 5, the nonvolatile memory 173 stores “180” as monitoring cycle data and “1” as an increase flag.

  In the example shown in FIG. 5, it is assumed that the monitoring cycle data stores a numerical value in units of seconds. That is, in the example illustrated in FIG. 5, the nonvolatile memory 173 stores “180 seconds (3 minutes)” as the monitoring cycle data. In the example shown in FIG. 5, when the increase flag is “1”, it indicates a short-term increase flag, and when the increase flag is “2”, it indicates a long-term increase flag. . That is, in the example illustrated in FIG. 5, the nonvolatile memory 173 stores a “short-term increase flag” as the increase flag.

  The nonvolatile memory 173 stores optimum pattern data by a buffer pool control unit 191 described later. Here, the “optimum pattern data” indicates the number of reception buffers that the buffer pool 140 has after the reception buffer is added or deleted. Such optimum pattern data is used when the transmission apparatus 100 is restarted. The restart process by the transmission apparatus 100 will be described later with reference to FIG.

  FIG. 6 shows an example of the optimum pattern data stored in the nonvolatile memory 173. In the example illustrated in FIG. 6, the nonvolatile memory 173 stores “100” as the number of 2048 [Byte] reception buffers. The non-volatile memory 173 stores “200” as the number of reception buffers of 1024 [Bytes], and stores “300” as the number of reception buffers of 512 [Bytes].

  That is, the optimum pattern data shown in FIG. 6 is that the buffer pool 140 has 2048 [Byte], 1024 [Byte], and 512 [Byte] reception buffers of “100”, “200”, and “300”, respectively. "It is optimal to have."

  The OS 180 is basic software installed in the transmission apparatus 100 and manages the entire transmission apparatus 100. The OS 180 includes a scheduling unit 181 and a memory management unit 182.

  The scheduling unit 181 activates the buffer pool control unit 191 based on the monitoring cycle data stored in the nonvolatile memory 173. For example, it is assumed that the nonvolatile memory 173 is in the state shown in FIG. In such a case, the scheduling unit 181 reads the monitoring cycle data “180” from the nonvolatile memory 173. Then, the scheduling unit 181 activates the buffer pool control unit 191 every “180 seconds (3 minutes)”.

  The memory management unit 182 performs reception buffer addition processing and deletion processing on the buffer pool 140. Specifically, the memory management unit 182 issues an interrupt prohibition signal to the CPU 171 when receiving the type and size of the reception buffer to be added or deleted from the buffer pool control unit 191 described later. Subsequently, the memory management unit 182 adds and deletes the reception buffer based on the type and size of the reception buffer received from the buffer pool control unit 191. Thereafter, the memory management unit 182 issues an interrupt prohibition release signal to the CPU 171.

  Note that the reason why the interrupt prohibition signal is issued to the CPU 171 when the reception buffer addition processing or deletion processing is performed is that the reception buffer to be added or the reception of the deletion target is received during the reception buffer addition processing or deletion processing. This is to prevent the buffer from being used.

  The buffer pool control unit 191 calculates the type and size of the reception buffer to be added to or deleted from the buffer pool 140 in conjunction with the optimum buffer pattern prediction unit 192, and stores the calculated type and size of the reception buffer in the memory management unit 182. Notice. The processing by the buffer pool control unit 191 and the optimum buffer pattern prediction unit 192 will be described in detail with reference to FIGS.

[Startup Process by Transmission Device According to Embodiment 1]
Next, a startup process performed by the transmission apparatus 100 according to the first embodiment will be described. FIG. 7 is a diagram illustrating a configuration example of the transmission apparatus 100 at the time of activation. The transmission apparatus 100 illustrated in FIG. 7 is the same apparatus as the transmission apparatus 100 illustrated in FIG. 3, but FIG. 7 illustrates only a processing unit related to the startup process.

  In the transmission apparatus 100 illustrated in FIG. 7, the storage unit 210 stores various program groups that form an OS and various applications. When the transmission apparatus 100 is activated, the CPU 171 activates the BOOT program 220 using the reset vector.

  The BOOT program 220 activates the kernel loader 230. The kernel loader 230 expands the kernel in the memory and activates the initialization unit 240. Note that the kernel loader 230 described above may be an IPL (Initial Program Loader).

  When the optimum pattern data is stored in the nonvolatile memory 173, the initialization unit 240 generates a reception buffer in the buffer pool 140 based on the optimum pattern data stored in the nonvolatile memory 173.

  For example, it is assumed that the nonvolatile memory 173 is in the state shown in FIG. In this case, the initialization unit 240 generates “100” reception buffers of 2048 [Bytes] in the buffer pool 140, generates “200” reception buffers of 1024 [Bytes], and receives 512 [Bytes]. Generate “300” buffers.

  On the other hand, when the optimum pattern data is not stored in the nonvolatile memory 173, the initialization unit 240 reads the pattern data from the system data, and generates a reception buffer in the buffer pool 140 based on the read pattern data. . Here, “system data” refers to an area in which initial values of various information are stored in advance in the transmission apparatus 100. That is, the pattern data stored in the system data indicates an initial value of the number of reception buffers generated by the transmission apparatus 100.

  As described above, when the buffer pool control unit 191 performs the process of adding or deleting the reception buffer with respect to the buffer pool 140, the number of reception buffers after the change is stored in the nonvolatile memory 173 as the optimum pattern data. Remember. Thereby, the transmission apparatus 100 is based on the optimum pattern data stored in the non-volatile memory 173 even when it is manually restarted or when it is restarted in the event of a failure. A receive buffer can be generated. That is, the transmission apparatus 100 can reproduce the configuration of the buffer pool 140 before the shutdown.

[Processing Procedure by Transmission Device According to Embodiment 1]
Next, procedures of various processes performed by the transmission apparatus 100 according to the first embodiment will be described with reference to FIGS.

[Packet reception processing procedure]
First, the procedure of packet reception processing by the transmission apparatus 100 according to the first embodiment will be described with reference to FIG. FIG. 8 is a flowchart illustrating a packet reception processing procedure performed by the transmission apparatus 100 according to the first embodiment.

  As illustrated in FIG. 8, the Ether driver 112 of the transmission apparatus 100 activates the network driver 120 when a packet is received by the Ether HD 111 (Yes in Step S101).

  The network driver 120 determines a reception buffer to be captured based on the size of the reception packet, stores the reception packet in the captured reception buffer (step S102), and activates the usage rate calculation unit 150.

  The usage rate calculation unit 150 activated by the network driver 120 calculates the usage rate of the buffer pool 140, and stores the calculated usage rate in the volatile memory 160 in association with the time when the packet is received (Step S1). S103). At this time, the usage rate calculation unit 150 stores the usage rate in the volatile memory 160 for each type of received packet.

  Also, the usage rate calculation unit 150 extracts the maximum usage rate from each usage rate calculated for each type of reception buffer, and determines a monitoring cycle based on the extracted maximum usage rate (step S104). Specifically, the usage rate calculation unit 150 determines that the monitoring cycle is set to a smaller value as the maximum usage rate is higher, and the monitoring cycle is set to a higher value as the maximum usage rate is lower.

  Subsequently, the usage rate calculation unit 150 calculates an increase rate of the usage rate for each type of reception buffer. Subsequently, the usage rate calculation unit 150 extracts the maximum increase rate from the increase rate of the usage rate calculated for each type of reception buffer. Then, when the extracted maximum increase rate is larger than the predetermined increase rate threshold (Yes at Step S105), the usage rate calculation unit 150 determines to set the increase flag as a short-term increase flag (Step S106). On the other hand, when the maximum increase rate is equal to or less than the increase rate threshold (No at Step S105), the usage rate calculation unit 150 determines to set the increase flag as the long-term increase flag (Step S107).

  Then, the usage rate calculation unit 150 stores the monitoring cycle determined in step 104 in the nonvolatile memory 173 (step S108). In addition, the usage rate calculation unit 150 stores the increase flag determined in Step S106 or Step S107 in the nonvolatile memory 173 (Step S108).

[Scheduling procedure]
Next, the procedure of the scheduling process by the scheduling unit 181 according to the first embodiment will be described with reference to FIG. FIG. 9 is a flowchart illustrating a scheduling process procedure performed by the scheduling unit 181 according to the first embodiment.

  As illustrated in FIG. 9, the scheduling unit 181 of the transmission apparatus 100 first reads the monitoring cycle data from the nonvolatile memory 173 and acquires the monitoring cycle (step S201). Then, when the acquired monitoring cycle has elapsed (Yes at Step S202), the scheduling unit 181 activates the buffer pool control unit 191 (Step S203). The scheduling unit 181 activates the buffer pool control unit 191 every time the monitoring cycle elapses (Yes at Step S202) (Step S203).

  The buffer pool control unit 191 activated by the scheduling unit 181 executes buffer pool control processing (step S204). The buffer pool control process by the buffer pool control unit 191 will be described later with reference to FIG.

[Buffer pool control processing procedure]
Next, the procedure of the buffer pool control process in step S204 of FIG. 9 will be described using FIG. FIG. 10 is a flowchart illustrating the buffer pool control processing procedure by the buffer pool control unit 191 in the first embodiment.

  As illustrated in FIG. 10, when the increase flag stored in the nonvolatile memory 173 is a short-term increase flag (step S301 short-term increase flag), the buffer pool control unit 191 activates the optimum buffer pattern prediction unit 192. Thus, a short-term pattern calculation process is performed (step S302). The short-term pattern calculation processing by the optimum buffer pattern prediction unit 192 will be described later with reference to FIG.

  On the other hand, when the increase flag stored in the non-volatile memory 173 is a long-term increase flag (step S301 long-term increase flag), the buffer pool control unit 191 activates the optimum buffer pattern prediction unit 192 and sets the long-term pattern. Calculation processing is performed (step S303). The long-term pattern calculation processing by the optimum buffer pattern prediction unit 192 will be described later with reference to FIG.

  Here, the optimum buffer pattern prediction unit 192 performs the short-term pattern calculation process or the long-term pattern calculation process, and determines that the buffer pool 140 is to be changed when it is determined that the reception buffer is to be added. Notification to the unit 191. At this time, the optimum buffer pattern prediction unit 192 notifies the buffer pool control unit 191 of the type of reception buffer to be added and the number of reception buffers to be added (hereinafter referred to as “additional number”).

  Further, when it is determined that the reception buffer is to be deleted, the optimum buffer pattern prediction unit 192 notifies the buffer pool control unit 191 of information indicating that the buffer pool 140 is to be changed. At this time, the optimum buffer pattern prediction unit 192 notifies the buffer pool control unit 191 of the type of reception buffer to be deleted and the number of reception buffers to be deleted (hereinafter referred to as “deletion number”).

  Also, if the optimum buffer pattern prediction unit 192 determines that the reception buffer addition processing and deletion processing are not performed on the buffer pool 140, the optimal buffer pattern prediction unit 192 notifies the buffer pool control unit 191 of information indicating that the buffer pool 140 is not changed. To do.

  When the buffer pool control unit 191 receives information indicating that the buffer pool 140 is not changed from the optimum buffer pattern prediction unit 192 (No in step S304), the buffer pool control unit 191 ends the processing.

  On the other hand, when the buffer pool control unit 191 receives information indicating that the buffer pool 140 is to be changed from the optimum buffer pattern prediction unit 192 (Yes in step S304), the change processing is performed as addition processing or deletion processing. It is determined which one (step S305).

  When the change process is an addition process (step S305 addition), the buffer pool control unit 191 determines the size of the reception buffer to be added for each type of reception buffer based on the additional number received from the optimum buffer pattern prediction unit 192. Calculate (step S306). Then, the buffer pool control unit 191 notifies the memory management unit 182 of the combination of the calculated reception buffer size and the reception buffer type.

  The memory management unit 182 that has received the combination of the size and type of the reception buffer from the buffer pool control unit 191 issues an interrupt prohibition signal to the CPU 171 (step S307). Subsequently, the memory management unit 182 secures, as a reception buffer, an area corresponding to the size of the reception buffer received from the buffer pool control unit 191 among the heap area and the reserve area of the memory, and stores the secured reception buffer in the buffer pool 140. It adds (step S308). Subsequently, the memory management unit 182 issues an interrupt prohibition release signal to the CPU 171 (step S309).

  When the reception buffer change processing by the memory management unit 182 is completed (Yes at Step S310), the buffer pool control unit 191 stores the buffer pattern of the buffer pool 140 after the change processing in the nonvolatile memory 173 as optimum pattern data. (Step S311).

  On the other hand, when the change process is a deletion process (deletion at step S305), the buffer pool control unit 191 determines the size of the reception buffer to be deleted based on the number of deletions received from the optimum buffer pattern prediction unit 192, and the type of reception buffer. It calculates for every (step S312).

  Subsequently, the buffer pool control unit 191 determines whether or not the size of the reception buffer is equal to or larger than the initial value when it is assumed that the reception buffer of the size calculated in step S312 is deleted from the buffer pool 140. (Step S313). The buffer pool control unit 191 performs the determination process in step S313 for each type of reception buffer.

  If the size of the reception buffer after deletion is smaller than the initial value (No at Step S313), the buffer pool control unit 191 ends the process. On the other hand, when the reception buffer of the buffer pool 140 after the deletion is equal to or larger than the initial value (Yes at Step S313), the buffer pool control unit 191 sets the combination of the size calculated at Step S312 and the type of the reception buffer to the memory management unit 182 is notified.

  Subsequently, the memory management unit 182 issues an interrupt prohibition signal to the CPU 171 (step S307), and deletes an area for the size received from the buffer pool control unit 191 from the buffer pool 140 (step S308). Subsequently, the memory management unit 182 issues an interrupt prohibition release signal to the CPU 171 (step S309).

  When the reception buffer changing process by the memory management unit 182 is completed (Yes at Step S310), the buffer pool control unit 191 stores the buffer pattern of the buffer pool 140 after the changing process in the nonvolatile memory 173 as optimum pattern data. Store (step S311).

[Short-term pattern calculation processing procedure]
Next, the procedure of the short-term pattern calculation process in step S302 of FIG. 10 will be described with reference to FIG. FIG. 11 is a flowchart illustrating a short-term pattern calculation processing procedure by the optimum buffer pattern prediction unit 192 according to the first embodiment.

  As shown in FIG. 11, when performing the short-term pattern calculation process, the optimum buffer pattern prediction unit 192 first reads out the short-term monitoring threshold value from the system data (step S401). The short-term monitoring threshold is a value in a predetermined range, for example, a value such as “30% to 60%”.

  Subsequently, the optimum buffer pattern prediction unit 192 determines whether or not there is a type of reception buffer whose usage rate exceeds the upper limit of the short-term monitoring threshold (step S402). For example, when the short-term monitoring threshold is “30% to 60%” as in the above example, the optimum buffer pattern prediction unit 192 receives the usage rate exceeding the upper limit “60%” of the short-term monitoring threshold. It is determined whether or not a buffer type exists.

  When there is a type of reception buffer that exceeds the upper limit of the short-term monitoring threshold (Yes in step S402), the optimum buffer pattern predicting unit 192 adds an additional buffer type that exceeds the upper limit of the short-term monitoring threshold. A prediction process is performed (step S403). When the optimum buffer pattern prediction unit 192 determines that the addition process is to be performed as a result of the prediction process for addition, the ratio between the current total size of the reception buffer and the size of the reception buffer to be added (hereinafter referred to as “addition ratio”). ) Is calculated. Note that the additional prediction processing by the optimum buffer pattern prediction unit 192 will be described later with reference to FIG.

  Subsequently, when the optimum buffer pattern prediction unit 192 determines that the addition process is not performed as a result of the prediction process for addition (No at Step S404), the process ends. On the other hand, if the optimum buffer pattern prediction unit 192 determines that the additional process is to be performed (Yes in step S404), the number of reception buffers to be added to the buffer pool 140 based on the additional ratio calculated in the additional prediction process, and the reception The type of buffer is determined (step S405).

  For example, it is assumed that the optimum buffer pattern prediction unit 192 determines to add a 512 [Byte] reception buffer as a result of the prediction process for addition. Here, it is assumed that the optimum buffer pattern prediction unit 192 calculates “10%” as the additional ratio. In such a case, the optimum buffer pattern prediction unit 192 calculates the number of reception buffers to be added so that the reception buffer of 512 [Bytes] increases by “10%” from the current state. For example, when the current 512 [Byte] reception buffers are 51200 [Byte] in total, the optimum buffer pattern prediction unit 192 increases “10%” as the number of reception buffers to be added in order to increase “10%”. calculate.

  Subsequently, the optimum buffer pattern prediction unit 192 adds a margin to the number of reception buffers determined in step S405 (step S406). Subsequently, the optimum buffer pattern prediction unit 192 notifies the buffer pool control unit 191 of information indicating that the buffer pool 140 is to be changed, the type of reception buffer to be added, and the number of additions (step S407).

  On the other hand, when there is no type of reception buffer that exceeds the upper limit of the short-term monitoring threshold (No in step S402), the optimum buffer pattern prediction unit 192 determines whether the usage rate is smaller than the lower limit of the short-term monitoring threshold. A determination is made for each type of reception buffer (step S408). For example, when the short-term monitoring threshold is “30% to 60%” as in the above example, the optimum buffer pattern prediction unit 192 determines whether the usage rate is smaller than the lower limit “30%” of the short-term monitoring threshold. Is determined for each type of reception buffer.

  If there is no reception buffer whose usage rate is smaller than the lower limit of the short-term monitoring threshold (No at step S408), the optimum buffer pattern prediction unit 192 ends the process. On the other hand, when there is a reception buffer whose usage rate is smaller than the lower limit of the short-term monitoring threshold (Yes in step S408), the optimum buffer pattern prediction unit 192 uses the reception buffer type whose usage rate is smaller than the lower limit of the short-term monitoring threshold. A deletion prediction process is performed (step S409). If the optimum buffer pattern prediction unit 192 determines that the deletion process is to be performed as a result of the deletion prediction process, the optimal buffer pattern prediction unit 192 is a ratio between the current total size of the reception buffer and the size of the reception buffer to be deleted (hereinafter referred to as “deletion ratio”) ) Is calculated. The deletion prediction process performed by the optimum buffer pattern prediction unit 192 will be described later with reference to FIG.

  Subsequently, when it is determined that the deletion process is not performed as a result of the deletion prediction process (No in step S410), the optimum buffer pattern prediction unit 192 ends the process. On the other hand, when it is determined that the deletion process is to be performed (Yes in step S410), the optimum buffer pattern prediction unit 192 determines the number of reception buffers to be deleted from the buffer pool 140 based on the deletion ratio calculated in the deletion prediction process, and the reception The type of buffer is determined (step S411).

  Subsequently, the optimum buffer pattern prediction unit 192 notifies the buffer pool control unit 191 of information indicating that the buffer pool 140 is to be changed, the type of reception buffer to be deleted, and the number of deletions (step S412).

  As described above, the transmission apparatus 100 according to the first embodiment performs only one of the reception buffer addition process and the deletion process for the buffer pool 140 in one process. In other words, the transmission apparatus 100 does not perform the reception buffer addition process and the deletion process at the same time. This is because if the addition process and the deletion process are performed simultaneously, the process of changing the reception buffer for the buffer pool 140 may become complicated. However, as in the processing procedure illustrated in FIG. 11, the transmission apparatus 100 preferentially performs the addition process over the deletion process, and thus can prevent the reception buffer from being exhausted.

[Long-term pattern calculation processing procedure]
Next, the procedure of the long-term pattern calculation process in step S303 in FIG. 10 will be described with reference to FIG. FIG. 12 is a flowchart illustrating a long-term pattern calculation processing procedure by the optimum buffer pattern prediction unit 192 according to the first embodiment.

  As shown in FIG. 12, when performing the long-term pattern calculation process, the optimum buffer pattern prediction unit 192 first reads a long-term monitoring threshold value from the system data (step S501). The long-term monitoring threshold is a predetermined value, for example, “60%”.

  Subsequently, the optimum buffer pattern prediction unit 192 determines whether or not there is a type of reception buffer whose usage rate exceeds the long-term monitoring threshold (step S502). If there is no type of reception buffer whose usage rate exceeds the long-term monitoring threshold (No in step S502), the optimum buffer pattern prediction unit 192 ends the process.

  On the other hand, when there is a reception buffer type that exceeds the long-term monitoring threshold (Yes in step S502), the optimum buffer pattern prediction unit 192 adds an additional buffer type that exceeds the upper limit of the long-term monitoring threshold. Prediction processing is performed (step S503). Note that the additional prediction processing by the optimum buffer pattern prediction unit 192 will be described later with reference to FIG.

  Subsequently, when the optimum buffer pattern prediction unit 192 determines that the addition process is not performed as a result of the prediction process for addition (No in step S504), the process ends. On the other hand, when it is determined that the addition process is to be performed (Yes in step S504), the optimum buffer pattern prediction unit 192 determines the number of reception buffers to be added to the buffer pool 140 and the type of reception buffer (step S505). Subsequently, the optimum buffer pattern prediction unit 192 adds a margin to the number of reception buffers determined in step S405 (step S506).

  Subsequently, the optimum buffer pattern prediction unit 192 notifies the buffer pool control unit 191 of information indicating that the buffer pool 140 is to be changed, the type of reception buffer to be added, and the number of additions (step S507).

  Thus, the optimum buffer pattern prediction unit 192 does not perform the process of deleting the reception buffer when performing the long-term pattern calculation process. That is, when the increase flag is a long-term increase flag, the transmission apparatus 100 does not perform a reception buffer deletion process. This is because, as described with reference to FIG. 2, when the usage rate gradually increases, the usage rate tends not to decrease thereafter.

[Additional prediction processing procedure]
Next, the procedure of the additional prediction process in step S403 in FIG. 11 and step S503 in FIG. 12 will be described with reference to FIG. FIG. 13 is a flowchart illustrating the additional prediction processing procedure performed by the optimum buffer pattern prediction unit 192 according to the first embodiment. The processing procedure shown in FIG. 13 is executed for each type of reception buffer for which it has been determined in step S403 or S503 that the usage rate exceeds the upper limit of the short-term monitoring threshold.

  As illustrated in FIG. 13, the optimal buffer pattern prediction unit 192 calculates a regression line of the usage rate with respect to time based on the monitoring data stored in the volatile memory 160 when performing the additional prediction process. (Step S601).

  Specifically, based on the time stored in the volatile memory 160, the optimum buffer pattern prediction unit 192 calculates a regression line “y = ax + b” when the elapsed time is xi and the usage rate is yi. . At this time, the optimum buffer pattern predicting unit 192 calculates constants a and b in the regression line according to the simultaneous equations of the following equations (1) and (2).

  Subsequently, the optimum buffer pattern prediction unit 192 calculates the usage rate of the buffer pool 140 in the next monitoring cycle by substituting the monitoring cycle into x of the calculated regression line (step S602). In the following, the usage rate predicted based on the fluctuation amount of the usage rate is referred to as “predicted usage rate”.

  Subsequently, the optimum buffer pattern prediction unit 192 calculates an additional ratio when the predicted usage rate is larger than the danger threshold (Yes at Step S603) (Step S604). Specifically, the optimal buffer pattern prediction unit 192 calculates the additional ratio by subtracting the current usage rate from the predicted usage rate. For example, when the predicted usage rate is “95%” and the current usage rate is “91%”, the optimum buffer pattern prediction unit 192 calculates “4%” as the additional rate.

  On the other hand, the optimal buffer pattern prediction unit 192 ends the process when the predicted usage rate is equal to or less than the risk threshold (No at Step S603).

[Prediction procedure for deletion]
Next, the procedure of the deletion prediction process in step S409 of FIG. 11 will be described with reference to FIG. FIG. 14 is a flowchart illustrating a deletion prediction processing procedure performed by the optimum buffer pattern prediction unit 192 according to the first embodiment. Note that the processing procedure shown in FIG. 14 is executed for each type of reception buffer for which it is determined in step S409 that the usage rate is smaller than the lower limit of the short-term monitoring threshold.

  As illustrated in FIG. 14, when performing the deletion prediction process, the optimal buffer pattern prediction unit 192 calculates a regression line of the usage rate over time based on the monitoring data stored in the volatile memory 160. (Step S701).

  Subsequently, the optimum buffer pattern prediction unit 192 calculates the predicted usage rate of the buffer pool 140 in the next cycle by substituting the monitoring cycle into x of the calculated regression line (step S702).

  Subsequently, the optimal buffer pattern prediction unit 192 calculates a deletion ratio when the predicted usage rate is smaller than the safety threshold (Yes at Step S703) (Step S704). Specifically, the optimum buffer pattern prediction unit 192 calculates the deletion ratio by subtracting the predicted usage rate from the current usage rate.

  On the other hand, when the predicted usage rate is equal to or greater than the safety threshold (No at Step S703), the optimum buffer pattern prediction unit 192 ends the process.

[Startup procedure]
Next, with reference to FIG. 15, a description will be given of a startup process procedure performed by the transmission apparatus 100 according to the first embodiment. FIG. 15 is a flowchart illustrating the activation processing procedure performed by the transmission apparatus 100 according to the first embodiment.

  When the transmission apparatus 100 is activated, the CPU 171 activates the BOOT program 220 with the reset vector. Then, the BOOT program 220 initializes the CPU 171 and starts the kernel loader 230. The kernel loader 230 expands the kernel in the memory and activates the initialization unit 240.

  Then, when the optimum pattern data is stored in the nonvolatile memory 173 (Yes at Step S801), the initialization unit 240 reads the optimum pattern data from the nonvolatile memory 173 (Step S802). Then, the initialization unit 240 generates a reception buffer in the buffer pool 140 based on the optimum pattern data read from the nonvolatile memory 173 (step S803).

  On the other hand, when the optimum pattern data is not stored in the nonvolatile memory 173 (No at Step S801), the initialization unit 240 reads the optimum pattern data from the system data (Step S804). Then, the initialization unit 240 generates a reception buffer in the buffer pool 140 based on the optimum pattern data read from the system data (Step S803).

[Effect of Example 1]
As described above, the transmission device 100 according to the first embodiment accumulates the buffer memory usage rate every time a packet is received, calculates the predicted usage rate based on the accumulated usage rate, and the predicted usage rate is dangerous. If it is greater than the threshold, add the receive buffer to the buffer pool. Also, the transmission device 100 deletes the added reception buffer from the buffer memory when the predicted usage rate is smaller than a predetermined safety threshold. As a result, the transmission apparatus 100 according to the first embodiment can dynamically generate a reception buffer according to the reception status of the packet even during the operation of the system, and thus can prevent the reception buffer from being exhausted.

  By the way, the transmission apparatus etc. which this application discloses may be implemented with a various different form other than the Example mentioned above. Accordingly, in the second embodiment, another embodiment of the transmission device disclosed in the present application will be described.

[Short-term pattern calculation processing procedure]
In the first embodiment, as described with reference to FIG. 11, the example in which the addition process and the deletion process of the reception buffer are not performed at the same time is shown. However, the transmission apparatus disclosed in the present application may simultaneously perform reception buffer addition processing and deletion processing. An example in which reception buffer addition processing and deletion processing are performed simultaneously will be described with reference to FIG.

  FIG. 16 is a flowchart showing a short-term pattern calculation processing procedure by the optimum buffer pattern prediction unit 192 when the addition process and the deletion process are performed simultaneously. As shown in FIG. 16, when performing the short-term pattern calculation process, the optimum buffer pattern predicting unit 192 first reads a short-term monitoring threshold value from the system data (step S901). Subsequently, the optimum buffer pattern prediction unit 192 performs the processing procedure in steps S902 to S912 for each type of reception buffer.

  Specifically, the optimum buffer pattern prediction unit 192 determines whether or not the usage rate of the reception buffer to be processed exceeds the upper limit of the short-term monitoring threshold (step S902). If the upper limit of the short-term monitoring threshold is exceeded (Yes at Step S902), the optimum buffer pattern prediction unit 192 performs an additional prediction process for the type of reception buffer to be processed (Step S903). On the other hand, when the usage rate of the processing target reception buffer does not exceed the upper limit of the short-term monitoring threshold (No in step S902), the optimum buffer pattern prediction unit 192 determines that the usage rate of the processing target reception buffer is the short-term monitoring threshold value. It is determined whether it is smaller than the lower limit (step S908). Note that the processing procedure in steps S903 to S912 is the same as the processing procedure in steps S403 to S412 shown in FIG.

  Then, the optimum buffer pattern prediction unit 192 ends the process when the processing procedure in steps S902 to S912 is performed for all types of reception buffers (Yes in step S913). On the other hand, when the above processing is not performed for all reception buffer types (No in step S913), the optimum buffer pattern prediction unit 192 performs the processing procedure in steps S902 to S912 for the unprocessed reception buffer types.

  As described above, the transmission apparatus 100 can perform the addition process and the deletion process at the same time by performing the short-term pattern calculation process for each reception buffer. For example, the transmission apparatus 100 can simultaneously perform processing of adding a reception buffer of 2048 [Byte] and deleting a reception buffer of 1024 [Byte]. Thereby, the transmission apparatus 100 can generate a reception buffer more appropriately according to the situation.

[Receive buffer type]
In the first embodiment, the buffer pool 140 of the transmission apparatus 100 has an example of having reception buffers of 2048 [Byte], 1024 [Byte], and 512 [Byte]. However, the transmission apparatus 100 may have a reception buffer of another size. For example, the transmission apparatus 100 may include 2048 [Byte], 1024 [Byte], 512 [Byte], 256 [Byte], and 128 [Byte] reception buffers. For example, the transmission apparatus 100 may have only a reception buffer of 2048 [Bytes].

[Addition ratio, Delete ratio]
Moreover, in the said Example 1, as shown in FIG.13 and FIG.14, the example which calculates an addition ratio and a deletion ratio by the difference of a predicted usage rate and the present usage rate was shown. However, the transmission apparatus 100 may calculate the size of the reception buffer to be added or deleted by another method. For example, the transmission apparatus 100 increases the size of the reception buffer to be added as the difference between the predicted usage rate and the danger threshold increases, or the size of the reception buffer to be deleted as the difference between the predicted usage rate and the safety threshold increases. May be increased. Further, for example, the transmission apparatus 100 may determine the size of the reception buffer to be added or deleted so that the usage rate after changing the size of the reception buffer becomes a desired value (for example, “50%”). Good.

[System configuration, etc.]
Further, the processing procedures, control procedures, specific names, information including various data and parameters shown in the above-mentioned documents and drawings can be arbitrarily changed unless otherwise specified. Further, each component of each illustrated apparatus is functionally conceptual, and does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each device is not limited to that shown in the figure, and all or a part thereof may be functionally or physically distributed or arbitrarily distributed in arbitrary units according to various loads or usage conditions. Can be integrated and configured. Further, all or a part of each processing function performed in each device may be realized by a CPU and a program analyzed and executed by the CPU, or may be realized as hardware by wired logic.

  The following supplementary notes are further disclosed with respect to the embodiments including the above examples.

(Supplementary note 1) a buffer memory having a plurality of reception buffers for storing received packets;
A calculation unit that calculates a usage rate of the buffer memory each time a packet is received;
Each time a predetermined monitoring period elapses, the fluctuation amount of the usage rate of the buffer memory is calculated based on the usage rate calculated by the calculation unit, and future use in the buffer memory is calculated based on the calculated fluctuation amount. A predictor that predicts a predicted usage rate,
A transmission apparatus comprising: a memory management unit that adds a reception buffer to the buffer memory when a predicted usage rate predicted by the prediction unit is greater than a predetermined risk threshold.

(Appendix 2) The buffer memory has a plurality of types of reception buffers having different sizes,
The calculation unit calculates a usage rate for each type of reception buffer,
The prediction unit predicts a predicted usage rate for each type of reception buffer based on the usage rate calculated by the calculation unit,
When there is a reception buffer type whose predicted usage rate predicted by the prediction unit is greater than a predetermined risk threshold, the memory management unit stores a reception buffer having a size corresponding to the reception buffer type in the buffer memory. The transmission apparatus according to attachment 1, wherein the transmission apparatus is added.

(Additional remark 3) The said calculation part sets the said monitoring period to a small value, so that the maximum usage rate which is the highest usage rate among the usage rates corresponding to each kind of reception buffer is large, and the said maximum usage rate is small. Set the monitoring cycle to a larger value,
3. The transmission apparatus according to appendix 2, wherein the prediction unit predicts a predicted usage rate for each type of reception buffer every time the monitoring period set by the calculation unit elapses.

(Additional remark 4) The said calculation part sets the short-term increase flag which shows that the usage rate increased in the short term, when the increase rate of the usage rate of the said buffer memory is larger than a predetermined increase rate threshold value,
When the short-term increase flag is set by the calculation unit and there is a type of reception buffer whose predicted usage rate predicted by the prediction unit is smaller than a predetermined safety threshold, the prediction unit 4. The transmission apparatus according to appendix 3, wherein a part of the reception buffer having a size corresponding to is deleted from the buffer memory.

(Additional remark 5) The said prediction part calculates the regression line of the usage rate with respect to time passage using the usage rate calculated by the said calculation part, and the time when this usage rate was calculated, The transmission apparatus according to any one of appendices 1 to 4, wherein the predicted usage rate is predicted based on a time corresponding to a next cycle.

(Additional remark 6) The buffer pattern memory | storage part which memorize | stores the buffer pattern which is a combination pattern with the kind of receiving buffer in the said buffer memory updated by the said memory management part, and the number of receiving buffers,
And an initialization unit that generates a reception buffer in the buffer memory based on a buffer pattern stored in the buffer pattern storage unit when the transmission apparatus is activated. The transmission apparatus as described in any one of -5.

(Additional remark 7) It is the transmission method by the transmission apparatus which transmits a packet,
The transmission device is
A calculation step of calculating a usage rate of a buffer memory having a plurality of reception buffers for storing received packets each time a packet is received;
Each time a predetermined monitoring period elapses, the fluctuation amount of the usage rate of the buffer memory is calculated based on the usage rate calculated by the calculation step, and future use in the buffer memory is calculated based on the calculated fluctuation amount. A forecasting step to forecast the forecasted usage,
And a memory management step of adding a reception buffer to the buffer memory when the predicted usage rate predicted by the prediction step is larger than a predetermined risk threshold.

100, 910, 920 Transmission device 111, 912 Ether HD
112, 913 Ether driver 120, 914, 924 Network driver 130, 915 Network protocol 140, 911, 921 Buffer pool 150 Usage rate calculation unit 160 Volatile memory 171 CPU
172 Timer
173 Non-volatile memory 180 OS
181 Scheduling unit 182 Memory management unit 191 Buffer pool control unit 192 Optimal buffer pattern prediction unit 210 Storage unit 220 BOOT program 230 Kernel loader 240 Initialization unit

Claims (4)

A buffer memory having a plurality of different types of reception buffers for storing received packets;
A calculation unit that calculates the usage rate of the buffer memory for each type of reception buffer each time a packet is received;
Each time a predetermined monitoring period elapses, the fluctuation amount of the usage rate of the buffer memory is calculated based on the usage rate calculated by the calculation unit, and future use in the buffer memory is calculated based on the calculated fluctuation amount. A prediction unit that predicts a predicted usage rate that is a rate for each type of reception buffer ;
A memory management unit that adds a reception buffer having a size corresponding to the type of the reception buffer to the buffer memory when there is a type of reception buffer whose predicted usage rate predicted by the prediction unit is greater than a predetermined risk threshold; equipped with a,
The calculation unit sets a short-term increase flag indicating that the usage rate has increased in the short-term when the increase rate of the usage rate of the buffer memory is greater than a predetermined increase rate threshold,
When the short-term increase flag is set by the calculation unit and there is a type of reception buffer whose predicted usage rate predicted by the prediction unit is smaller than a predetermined safety threshold, the prediction unit A transmission apparatus characterized in that a part of the reception buffer having a size corresponding to is deleted from the buffer memory . The calculation unit sets the monitoring cycle to a smaller value as the maximum usage rate that is the highest usage rate among the usage rates corresponding to each type of reception buffer is larger, and the monitoring cycle as the maximum usage rate is smaller. Is set to a large value,
The transmission apparatus according to claim 1 , wherein the prediction unit predicts a predicted usage rate for each type of reception buffer each time the monitoring period set by the calculation unit elapses. A buffer pattern storage unit that stores a buffer pattern that is a combination pattern of the type of reception buffer in the buffer memory updated by the memory management unit and the number of reception buffers;
An initialization unit that generates a reception buffer in the buffer memory based on a buffer pattern stored in the buffer pattern storage unit when the transmission apparatus is activated. The transmission apparatus according to 1 or 2 . A transmission method by a transmission device for transmitting packets,
The transmission device is
A calculation step of calculating a usage rate of a buffer memory having a plurality of types of reception buffers having different sizes for storing received packets for each type of reception buffer each time a packet is received;
Each time a predetermined monitoring period elapses, the fluctuation amount of the usage rate of the buffer memory is calculated based on the usage rate calculated by the calculation step, and future use in the buffer memory is calculated based on the calculated fluctuation amount. A prediction step for predicting a predicted usage rate that is a rate for each type of reception buffer ;
A memory management step of adding a reception buffer having a size corresponding to the type of the reception buffer to the buffer memory when there is a reception buffer type having a predicted usage rate predicted by the prediction step larger than a predetermined risk threshold; only including,
The calculation step sets a short-term increase flag indicating that the usage rate has increased in the short-term when the increase rate of the usage rate of the buffer memory is greater than a predetermined increase rate threshold,
In the prediction step, when the short-term increase flag is set in the calculation step and there is a reception buffer type for which the predicted usage rate predicted in the prediction step is smaller than a predetermined safety threshold, the type of the reception buffer A transmission method comprising: deleting a part of the reception buffer having a size corresponding to the buffer memory from the buffer memory .

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