U.S. patent application number 10/698069 was filed with the patent office on 2005-05-05 for method and system for internet transport acceleration without protocol offload.
This patent application is currently assigned to International Business Machines Corporation. Invention is credited to Ko, Machael A., Sarkar, Prasenjit.
Application Number | 20050097242 10/698069 |
Document ID | / |
Family ID | 34550524 |
Filed Date | 2005-05-05 |
United States Patent
Application |
20050097242 |
Kind Code |
A1 |
Sarkar, Prasenjit ; et
al. |
May 5, 2005 |
Method and system for internet transport acceleration without
protocol offload
Abstract
A packet classifier within a network adapter detects an
application packet header belonging to a packet in a data stream
associated with an application that uses a network protocol, such
as TCP/IP, SNA or IPX. Offsets included within the application
header are identified and a plurality of registers is loaded with
the identified offsets. Each of a plurality direct data placement
patterns are masked with contents of the loaded registers. Each
direct data placement pattern is associated with an application
packet header and includes a corresponding I/O context.
Additionally, each direct data placement pattern includes a
corresponding connection path for direct placement of a payload
corresponding to the detected application header in a memory that
is utilized by the application.
Inventors: |
Sarkar, Prasenjit; (San
Jose, CA) ; Ko, Machael A.; (Queensbridge Court,
CA) |
Correspondence
Address: |
JOSEPH P. CURTIN
1469 N.W. MORGAN LANE
PORTLAND
OR
97229
US
|
Assignee: |
International Business Machines
Corporation
Armonk
NY
|
Family ID: |
34550524 |
Appl. No.: |
10/698069 |
Filed: |
October 30, 2003 |
Current U.S.
Class: |
710/36 |
Current CPC
Class: |
H04L 69/22 20130101;
H04L 69/161 20130101; H04L 69/16 20130101; H04L 69/10 20130101 |
Class at
Publication: |
710/036 |
International
Class: |
G06F 003/00 |
Claims
What is claimed is:
1. A method for direct data placement of data for an application
that uses a network protocol, the method comprising: detecting an
application packet header using a packet classifier within a
network adapter, the application packet header belonging to a
packet in a data stream associated with the application;
identifying offsets included within the application header; loading
a plurality of registers with the identified offsets; initiating
direct data placement of data associated with the application
packet header when a result of masking a set of values
corresponding to a direct data placement pattern with contents of
the loaded registers matches one of at least one direct data
placement pattern, each direct data placement pattern being
associated with an application packet header.
2. The method according to claim 1, wherein a plurality of direct
data placement patterns are available for masking with the contents
of the loaded registers.
3. The method according to claim 2, further comprising masking each
of the plurality direct data placement patterns with contents of
the loaded registers.
4. The method according to claim 1, wherein each direct data
placement pattern includes a corresponding I/O context.
5. The method according to claim 1, wherein each direct data
placement pattern includes a corresponding connection path for
direct placement of a payload corresponding to the detected
application header in a memory that is utilized by the
application.
6. The method according to claim 1, wherein initiating direct data
placement includes: extracting information corresponding to the
detected application header; and mapping a payload of the detected
applications header to a memory based on the direct data placement
pattern.
7. The method according to claim 6, wherein the memory is a
predetermined region of memory associated with the application.
8. The method according to claim 1, further comprising generating
only one interrupt of a host processor for the network adapter for
each message.
9. The method according to claim 1, wherein when initiating direct
data placement of data associated with the application packet
header is performed, a host processor for the network adapter does
not perform copy and checksum processing.
10. The method according to claim 1, wherein the network protocol
is TCP/IP.
11. The method according to claim 1, wherein the network protocol
is SNA.
12. The method according to claim 1, wherein the network protocol
is IPX.
13. A network adapter, comprising: an interface to a protocol-based
network; and a packet classifier, the packet classifier detecting
an application packet header, the application packet header
belonging to a packet in a data stream associated with an
application that uses the protocol, the packet classifier
identifying offsets included within the application header, loading
a plurality of registers with the identified offsets, and
initiating direct data placement of data associated with the
application packet header when a result of masking a set of values
corresponding to a direct data placement pattern with contents of
the loaded registers matches one of at least one direct data
placement pattern, each direct data placement pattern being
associated with an application packet header.
14. The network adapter according to claim 13, wherein a plurality
of direct data placement patterns are available for masking with
the contents of the loaded registers.
15. The network adapter according to claim 14, wherein the packet
classifier masks each of the plurality direct data placement
patterns with contents of the loaded registers.
16. The network adapter according to claim 13, wherein each direct
data placement pattern includes a corresponding I/O context.
17. The network adapter according to claim 13, wherein each direct
data placement pattern includes a corresponding connection path for
direct placement of a payload corresponding to the detected
application header in a memory that is utilized by the
application.
18. The network adapter according to claim 13, wherein when the
packet classifier initiates direct data placement, the packet
classifier extracts information corresponding to the detected
application header and DMA-s a payload of the detected applications
header to a memory based on the direct data placement pattern.
19. The network adapter according to claim 18, wherein the memory
is a predetermined region of memory associated with the
application.
20. The network adapter according to claim 13, wherein the packet
classifier generates only one interrupt of a host processor for the
network adapter for each TCP message.
21. The network adapter according to claim 13, wherein when the
packet classifier initiates direct data placement of data
associated with the application packet header is performed, a host
processor for the network adapter does not perform copy and
checksum processing.
22. The network according to claim 13, wherein the network protocol
is TCP/IP.
23. The network according to claim 13, wherein the network protocol
is SNA.
24. The network according to claim 13, wherein the network protocol
is IPX.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a network system. More
particularly, the present invention relates to a system and a
method for direct data placement of data for an application that
uses a network protocol, such as TCP/IP, SNA and/or IPX
[0003] 2. Description of the Related Art
[0004] Internet protocols, such as TCP/IP, and other networking
protocols, such as SNA and IPX, are crucial to the performance of
many applications. The vast majority of communication protocols for
current applications use TCP/IP as the transport protocol.
Consequently, both researchers and practitioners have focused on
performance improvements for TCP/IP.
[0005] The most popular conventional approach for improving TCP/IP
performance is to offload the entire TCP/IP stack onto a network
adapter. See, for example, U.S. Pat. No. 6,434,620B1 to L. B.
Boucher et al. and U.S. Patent Application 2002/016191 A1 to L. B.
Boucher et al. Offloading the entire TCP/IP stack onto a network
adapter has many advantages. For example, interrupt overhead for
the host processor is reduced because there is only one interrupt
per TCP message as opposed to one interrupt for each TCP segment.
Offloading the entire TCP/IP stack also relieves the burden of
TCP/IP processing from the host processor, particularly the
copy-and-checksum processing overheads, and saves precious CPU
cycles. Further, offloading the TCP/IP stack provides the
opportunity for direct data placement on the receive path based on
application header processing on the network adapter.
[0006] A drawback of offloading the TCP/IP stack onto a network
adapter, however, is that the processing power of a network adapter
is not comparable to the processing power of a general purpose CPU
and such offloading may cause bottlenecks. Recent studies have
shown that the performance of the TCP/IP offload adapters is
sometimes behind that of a software TCP/IP stack.
[0007] Consequently, what is needed is a technique for direct data
placement of data for a TCP/IP application without offloading the
protocol onto a network adapter.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention provides a technique for direct data
placement of data for a TCP/IP application without offloading the
protocol onto a network adapter.
[0009] The advantages of the present invention are provided by a
system and method for direct data placement of data for an
application that uses a network protocol, such as TCP/IP, SNA or
IPX. According to the invention, an application packet header is
detected using a packet classifier within a network adapter. The
application packet header belongs to a packet in a data stream
associated with the application. Offsets included within the
application header are then identified and a plurality of registers
is loaded with the identified offsets. Each of a plurality direct
data placement patterns are masked with contents of the loaded
registers. Direct data placement of data associated with the
application packet header is initiated when a result of masking a
set of values corresponding to a direct data placement pattern with
contents of the loaded registers matches one of at least one direct
data placement pattern. Each direct data placement pattern is
associated with an application packet header and includes a
corresponding I/O context. Additionally, each direct data placement
pattern includes a corresponding connection path for direct
placement of a payload corresponding to the detected application
header in a memory that is utilized by the application.
[0010] When direct data placement is initiated, information
corresponding to the detected application header is extracted and
the data payload of the detected applications header is DMA-ed to
registered memory that is associated with the application, based on
the direct data placement pattern. Only one interrupt of a host
processor for the network adapter is generated for each message.
Moreover, when direct data placement of data associated with the
application packet header is initiated, a host processor for the
network adapter does not perform copy and checksum processing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention is illustrated by way of example and
not by limitation in the accompanying figures in which like
reference numerals indicate similar elements and in which:
[0012] FIG. 1 shows a functional block diagram of a computer system
having a network adapter with a packet classifier according to the
present invention; and
[0013] FIG. 2 show a flowchart of a process for accelerating TCP/IP
applications without offloading the TCP/IP stack onto a network
adapter according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention provides a technique for accelerating
TCP/IP applications without offloading the TCP/IP stack onto a
network adapter. Instead, the present invention offloads
application-programmable intelligence onto a network adapter that
provides a programmable packet classifier for direct data placement
for TCP applications, thereby providing most of the benefits
associated with conventional offloading of the TCP/IP stack to a
network adapter.
[0015] The present invention provides many advantages. For example,
system interrupts are reduced because the system is interrupted
only on the transfer of data and not for every incoming TCP/IP
packet. Additionally, TCP/IP copy overhead is eliminated because
the programmable interface does direct data placement based on the
classifier recognizing application headers. Moreover, direct data
placement is an inbuilt advantage of the present invention.
[0016] While the present invention is as advantageous as a
conventional system that offloads TCP/IP stack processing, the
present invention provides two additional benefits over such
conventional systems. First, the complexity of the programmable
packet classifier of the present invention is much less than the
complexity of the entire TCP/IP stack. Consequently, a network
adapter having a programmable packet classifier of the present
invention is less costly. Second, the present invention leaves
TCP/IP processing on the host processor, thereby allowing the
performance to scale with CPU speeds.
[0017] FIG. 1 shows a functional block diagram of a computer system
100 having a network adapter with a packet classifier according to
the present invention. Computer system 100 includes a host
processor 101, a TCP/IP stack 102 and a network adapter 103.
Network adapter 103 includes a packet classifier 104 having a
programming interface 105, and is connected to network 106, such as
an Ethernet.
[0018] Programming interface 105 for packet classifier 104 includes
a programmable interface that is programmed by a TCP/IP
application. The first programmable parameter is a set of registers
R that contain values that are to be loaded from a TCP stream. The
second programmable parameter is the set of offsets O that indicate
where the values loaded into registers R are located in the
application header. The third programmable parameter is a set of
masks M that are applied to the contents of registers R. The fourth
programmable parameter is a set of values V that are to be matched
with the results of masking the contents of registers R masked with
the contents of masks M. The fifth programmable parameter is the
action A that is to be taken when a pattern is matched. Action A
can have additional associated parameters depending on the action
taken. The application separately programs a cache of I/O tags to
reserved memory RM for each corresponding I/O tag in a well-known
manner.
[0019] The present invention requires that the TCP stream has
application header synchronization. Additionally, the present
invention does not provide application header resynchronization
because loss of application header synchronization is usually
handled by protocol action, such as by markers, or by breaking down
the connection.
[0020] FIG. 2 show a flowchart 200 of a process for accelerating
TCP/IP applications without offloading the TCP/IP stack onto a
network adapter according to the present invention. At step 201, a
TCP/IP application programs the R, O, M, V and A programmable
parameters of packet classifier 104. At step 202, TCP/IP
communications are monitor by packet classifier 104 and it is
determined whether an application header is detected. If not, flow
remains at step 202. Otherwise, when packet classifier detects an
application header, flow continues to step 203 where packet
classifier 104 loads registers R from offsets O in the detected
header and at step 204 masks values V with the contents of
registers R. At step 205, it is determined whether the results of
the masking match the results with a corresponding programmed
pattern. When the results of the masking match a programmed
patterned, flow continues to step 206 where packet classifier 104
takes action A that is specified in the pattern. When action A
involves direct data placement, head information (i.e., I/O tags
and protocol details) are extracted for DMA-ing the data payload of
the of the application header to reserved memory RM associated with
the application. For example, when an I/O tag corresponds to
reserved memory RM1-RM2, action A involves moving the contents of
TCP sequence numbers S1-S2 to RM1-RM2. Flow continues to step
202.
[0021] If, at step 205, the results of the masking do not match a
programmed pattern, then flow continues to step 207 where it is
determined whether there are no TCP header in incoming packets
because there is IP fragmentation. If so, then flow continues to
step 208 where the task of moving the contents of TCP sequence
numbers is hindered by the fragmentation and is best done through
action A' in which additional programming of registers R', masks
M', values V' and offsets O' is done to map the fragmented IP
headers to the TCP stream. Flow continues to step 202.
[0022] If at step 207, IP fragmentation is not detected, flow
continues to step 209 where the incoming TCP/IP packets doe not
match any pattern because there are out-of-order packets causing
missing application headers. At step 209, the incoming TCP/IP
packets are sent directly to the host TCP/IP stack for processing.
At this point, the TCP/IP packet is subjected to the
copy-and-checksum overhead. Alternatively, the out-of-order packets
are buffered in network adapter 103. For high data rates, though,
this alternative increases the memory requirements of network
adapter 103.
[0023] While the present invention has been described using TCP/IP
as an exemplary network protocol, it should be understood that the
present invention is applicable for other network protocols, such
as SNA or IPX.
[0024] Although the foregoing invention has been described in some
detail for purposes of clarity of understanding, it will be
apparent that certain changes and modifications may be practiced
that are within the scope of the appended claims. Accordingly, the
present embodiments are to be considered as illustrative and not
restrictive, and the invention is not to be limited to the details
given herein, but may be modified within the scope and equivalents
of the appended claims.
* * * * *