106 lines
3.6 KiB
Plaintext
106 lines
3.6 KiB
Plaintext
#
|
|
# For a description of the syntax of this configuration file,
|
|
# see the file kconfig-language.txt in the NuttX tools repository.
|
|
#
|
|
|
|
menu "Common I/O Buffer Support"
|
|
|
|
config MM_IOB
|
|
bool "Enable generic I/O buffer support"
|
|
default n
|
|
---help---
|
|
This setting will build the common I/O buffer (IOB) support
|
|
library.
|
|
|
|
if MM_IOB
|
|
|
|
config IOB_NBUFFERS
|
|
int "Number of pre-allocated I/O buffers"
|
|
default 36 if NET_WRITE_BUFFERS
|
|
default 24 if !NET_WRITE_BUFFERS && NET_READAHEAD
|
|
default 8 if !NET_WRITE_BUFFERS && !NET_READAHEAD
|
|
---help---
|
|
Each packet is represented by a series of small I/O buffers in a
|
|
chain. This setting determines the number of preallocated I/O
|
|
buffers available for packet data.
|
|
|
|
config IOB_BUFSIZE
|
|
int "Payload size of one I/O buffer"
|
|
default 196
|
|
---help---
|
|
Each packet is represented by a series of small I/O buffers in a
|
|
chain. This setting determines the data payload each preallocated
|
|
I/O buffer.
|
|
|
|
config IOB_NCHAINS
|
|
int "Number of pre-allocated I/O buffer chain heads"
|
|
default 0 if !NET_READAHEAD
|
|
default IOB_NBUFFERS if NET_READAHEAD
|
|
---help---
|
|
These tiny nodes are used as "containers" to support queueing of
|
|
I/O buffer chains. This will limit the number of I/O transactions
|
|
that can be "in-flight" at any give time. The default value of
|
|
zero disables this features.
|
|
|
|
These generic I/O buffer chain containers are not currently used
|
|
by any logic in NuttX. That is because their other specialized
|
|
I/O buffer chain containers that also carry a payload of usage
|
|
specific information.
|
|
|
|
Note: TCP doesn't use this.
|
|
Note: UDP and CAN use this.
|
|
|
|
config IOB_THROTTLE
|
|
int "I/O buffer throttle value"
|
|
default 0 if !NET_WRITE_BUFFERS || !NET_READAHEAD
|
|
default 8 if NET_WRITE_BUFFERS && NET_READAHEAD
|
|
---help---
|
|
TCP write buffering and read-ahead buffer use the same pool of free
|
|
I/O buffers. In order to prevent uncontrolled incoming TCP packets
|
|
from hogging all of the available, pre-allocated I/O buffers, a
|
|
throttling value is required. This throttle value assures that
|
|
I/O buffers will be denied to the read-ahead logic before TCP writes
|
|
are halted.
|
|
|
|
config IOB_NOTIFIER
|
|
bool "Support IOB notifications"
|
|
default n
|
|
depends on SCHED_WORKQUEUE
|
|
select WQUEUE_NOTIFIER
|
|
---help---
|
|
Enable building of IOB notifier logic that will execute a worker
|
|
function on the high priority work queue when an IOB is available.
|
|
This is is a general purpose notifier, but was developed specifically to
|
|
support poll() logic where the poll must wait for an IOB to become
|
|
available.
|
|
|
|
config IOB_NOTIFIER_DIV
|
|
int "Notification divider"
|
|
default 4
|
|
range 1 64
|
|
depends on IOB_NOTIFIER
|
|
---help---
|
|
IOBs may become available at very high rates and the resulting
|
|
notification processing can be substantial even if there is nothing
|
|
waiting for a free IOB. This divider will reduce that rate of
|
|
notification. This must be an even power of two. Supported values
|
|
include: 1, 2, 4, 8, 16, 32, 64. The default value of 4 means that
|
|
a notification will be sent only when there are a multiple of 4 IOBs
|
|
available.
|
|
|
|
config IOB_DEBUG
|
|
bool "Force I/O buffer debug"
|
|
default n
|
|
depends on DEBUG_FEATURES && !SYSLOG_BUFFER
|
|
---help---
|
|
This option will force debug output from I/O buffer logic. This
|
|
is not normally something that would want to do but is convenient
|
|
if you are debugging the I/O buffer logic and do not want to get
|
|
overloaded with other un-related debug output.
|
|
|
|
NOTE that this selection is not available if IOBs are being used
|
|
to syslog buffering logic (CONFIG_SYSLOG_BUFFER=y)!
|
|
|
|
endif # MM_IOB
|
|
endmenu # Common I/O buffer support
|