From 8720bd643ef37a693984baba83c37458f6691df1 Mon Sep 17 00:00:00 2001 From: Andrei Vagin Date: Tue, 22 Oct 2019 11:54:14 -0700 Subject: netstack/tcp: software segmentation offload Right now, we send each tcp packet separately, we call one system call per-packet. This patch allows to generate multiple tcp packets and send them by sendmmsg. The arguable part of this CL is a way how to handle multiple headers. This CL adds the next field to the Prepandable buffer. Nginx test results: Server Software: nginx/1.15.9 Server Hostname: 10.138.0.2 Server Port: 8080 Document Path: /10m.txt Document Length: 10485760 bytes w/o gso: Concurrency Level: 5 Time taken for tests: 5.491 seconds Complete requests: 100 Failed requests: 0 Total transferred: 1048600200 bytes HTML transferred: 1048576000 bytes Requests per second: 18.21 [#/sec] (mean) Time per request: 274.525 [ms] (mean) Time per request: 54.905 [ms] (mean, across all concurrent requests) Transfer rate: 186508.03 [Kbytes/sec] received sw-gso: Concurrency Level: 5 Time taken for tests: 3.852 seconds Complete requests: 100 Failed requests: 0 Total transferred: 1048600200 bytes HTML transferred: 1048576000 bytes Requests per second: 25.96 [#/sec] (mean) Time per request: 192.576 [ms] (mean) Time per request: 38.515 [ms] (mean, across all concurrent requests) Transfer rate: 265874.92 [Kbytes/sec] received w/o gso: $ ./tcp_benchmark --client --duration 15 --ideal [SUM] 0.0-15.1 sec 2.20 GBytes 1.25 Gbits/sec software gso: $ tcp_benchmark --client --duration 15 --ideal --gso $((1<<16)) --swgso [SUM] 0.0-15.1 sec 3.99 GBytes 2.26 Gbits/sec PiperOrigin-RevId: 276112677 --- pkg/tcpip/link/rawfile/BUILD | 5 ++++- pkg/tcpip/link/rawfile/rawfile_unsafe.go | 11 +++++++++++ 2 files changed, 15 insertions(+), 1 deletion(-) (limited to 'pkg/tcpip/link/rawfile') diff --git a/pkg/tcpip/link/rawfile/BUILD b/pkg/tcpip/link/rawfile/BUILD index 2e8bc772a..05c7b8024 100644 --- a/pkg/tcpip/link/rawfile/BUILD +++ b/pkg/tcpip/link/rawfile/BUILD @@ -16,5 +16,8 @@ go_library( visibility = [ "//visibility:public", ], - deps = ["//pkg/tcpip"], + deps = [ + "//pkg/tcpip", + "@org_golang_x_sys//unix:go_default_library", + ], ) diff --git a/pkg/tcpip/link/rawfile/rawfile_unsafe.go b/pkg/tcpip/link/rawfile/rawfile_unsafe.go index 7e286a3a6..44e25d475 100644 --- a/pkg/tcpip/link/rawfile/rawfile_unsafe.go +++ b/pkg/tcpip/link/rawfile/rawfile_unsafe.go @@ -22,6 +22,7 @@ import ( "syscall" "unsafe" + "golang.org/x/sys/unix" "gvisor.dev/gvisor/pkg/tcpip" ) @@ -101,6 +102,16 @@ func NonBlockingWrite3(fd int, b1, b2, b3 []byte) *tcpip.Error { return nil } +// NonBlockingSendMMsg sends multiple messages on a socket. +func NonBlockingSendMMsg(fd int, msgHdrs []MMsgHdr) (int, *tcpip.Error) { + n, _, e := syscall.RawSyscall6(unix.SYS_SENDMMSG, uintptr(fd), uintptr(unsafe.Pointer(&msgHdrs[0])), uintptr(len(msgHdrs)), syscall.MSG_DONTWAIT, 0, 0) + if e != 0 { + return 0, TranslateErrno(e) + } + + return int(n), nil +} + // PollEvent represents the pollfd structure passed to a poll() system call. type PollEvent struct { FD int32 -- cgit v1.2.3