Buffer Sizes

The size of each buffer can be tuned on a per-consumer basis. Separate options are provided to tune each buffer size, as shown in the following table:

Buffer	Size Option
Principal	bufsize
Speculative	specsize
Aggregation	aggsize

Each of these options is set with a value that denotes the size. As with any size option, the value may have an optional size suffix. See Chapter 16, Options and Tunables for more details. For example, to set the buffer size to one megabyte on the command line to dtrace, you can use -x to set the option:

# dtrace -P syscall -x bufsize=1m

Alternatively, you can use the -b option to dtrace:

# dtrace -P syscall -b 1m

Finally, you could can set bufsize using #pragma D option:

#pragma D option bufsize=1m

The buffer size you select denotes the size of the buffer on each CPU. Moreover, for the switch buffer policy, bufsize denotes the size of each buffer on each CPU. The buffer size defaults to four megabytes.