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05/05/2020

What is ring buffer in NIC?

What is ring buffer in NIC?

Ring buffers, also known as circular buffers, are shared buffers between the device driver and Network Interface Card (NIC). These buffers store incoming packets until the device driver can process them.

How do I know my NIC ring buffer size in Linux?

The RX ring buffer size can be examined with the ethtool -g command. The default RX Ring size is 256 (the maximum is 4096). User can increase this with the ethtool -G command. Monitor the ifconfig output to see if the RX drops stop.

What is a ring buffer Linux?

The kernel ring buffer is a data structure that records messages related to the operation of the kernel. A ring buffer is a special kind of buffer that is always a constant size, removing the oldest messages when new messages are received.

What is ring buffer size?

When you deal with large volumes of data, it is crucial that you tune the Receive (RX) and Transmit (TX) ring buffer size. The ring buffers contain descriptors or pointers to the socket kernel buffers that hold the packet data. If you set a low ring buffer size for data transfer, packets might get dropped.

Why does a NIC have a buffer?

A packet buffer is memory space set aside for storing packets awaiting transmission over networks or storing packets received over networks. These memory spaces are either located in a network interface card (NIC) or in the computer that holds the card.

Does NIC have buffer?

Buffer management is a feature that enables Network Interface Card (NIC) client drivers and the operating system to work together when allocating packet data buffers from system memory for the transmit (Tx) and receive (Rx) data paths.

What is Ethtool command in Linux?

Ethtool is a Network Interface Card configuration command that allows you to retrieve information and change your NIC settings. These settings include Speed, Duplex, Auto-Negotiation, and many other parameters.

What is RX and TX buffer?

Transmit and receive buffers are used to regulate the flow of data frames between adapters and protocol stacks. Although the default settings are usually acceptable, increasing the number may improve performance if network traffic is heavy, but it will also use system memory.

How does a ring buffer work?

Circular buffers (also known as ring buffers) are fixed-size buffers that work as if the memory is contiguous & circular in nature. As memory is generated and consumed, data does not need to be reshuffled – rather, the head/tail pointers are adjusted. When data is added, the head pointer advances.

Where are ring buffer logs stored in Linux?

/var/log/boot.
Users can display data stored in the kernel ring buffer through the dmesg command or the /var/log/boot. log file. When the ring buffer is full, the new data overwrites the old.

What does a ring buffer do?

In computer science, a circular buffer, circular queue, cyclic buffer or ring buffer is a data structure that uses a single, fixed-size buffer as if it were connected end-to-end. This structure lends itself easily to buffering data streams.

What are ring buffers used for?

Ring Buffer (or Circular Buffer) is a bounded circular data structure that is used for buffering data between two or more threads.