From e875cbd9aaec22264da01b76958e565b3262e970 Mon Sep 17 00:00:00 2001 From: Brad Fitzpatrick Date: Mon, 17 Apr 2023 13:32:03 -0700 Subject: [PATCH] syscall: add a sync.Pool for a NetlinkRIB scratch buffer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The syscall.NetlinkRIB signature means it necessarily allocates but this changes makes it allocate a bit less. For example, in the net package: name old time/op new time/op delta Interfaces-8 59.1µs ± 3% 57.3µs ± 2% -3.02% (p=0.000 n=10+10) InterfaceByIndex-8 53.1µs ± 5% 50.6µs ± 2% -4.81% (p=0.000 n=10+10) InterfaceByName-8 59.3µs ± 2% 57.4µs ± 1% -3.29% (p=0.000 n=10+10) InterfaceAddrs-8 105µs ± 1% 101µs ± 1% -4.22% (p=0.000 n=10+9) InterfacesAndAddrs-8 38.2µs ± 3% 36.3µs ± 2% -4.98% (p=0.000 n=10+10) InterfacesAndMulticastAddrs-8 152µs ± 2% 154µs ± 6% ~ (p=0.105 n=10+10) name old alloc/op new alloc/op delta Interfaces-8 22.8kB ± 0% 18.7kB ± 0% -17.90% (p=0.000 n=10+9) InterfaceByIndex-8 16.2kB ± 0% 12.1kB ± 0% -25.22% (p=0.000 n=10+10) InterfaceByName-8 22.8kB ± 0% 18.8kB ± 0% -17.85% (p=0.000 n=10+10) InterfaceAddrs-8 36.6kB ± 0% 28.5kB ± 0% -22.28% (p=0.000 n=10+10) InterfacesAndAddrs-8 9.60kB ± 0% 5.51kB ± 0% -42.59% (p=0.000 n=10+7) InterfacesAndMulticastAddrs-8 141kB ± 0% 141kB ± 0% ~ (all equal) name old allocs/op new allocs/op delta Interfaces-8 53.0 ± 0% 52.0 ± 0% -1.89% (p=0.000 n=10+10) InterfaceByIndex-8 28.0 ± 0% 27.0 ± 0% -3.57% (p=0.000 n=10+10) InterfaceByName-8 54.0 ± 0% 53.0 ± 0% -1.85% (p=0.000 n=10+10) InterfaceAddrs-8 155 ± 0% 153 ± 0% -1.29% (p=0.000 n=10+10) InterfacesAndAddrs-8 38.0 ± 0% 37.0 ± 0% -2.63% (p=0.000 n=10+10) InterfacesAndMulticastAddrs-8 77.0 ± 0% 77.0 ± 0% ~ (all equal) Signed-off-by: Brad Fitzpatrick Change-Id: Ic3278b2c000af78d7ed816645463c3b7ff0c90ca Reviewed-on: https://go-review.googlesource.com/c/go/+/485455 TryBot-Result: Gopher Robot Reviewed-by: Ian Lance Taylor Reviewed-by: Bryan Mills --- src/net/interface_test.go | 6 ++++++ src/syscall/netlink_linux.go | 16 +++++++++++++--- 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/src/net/interface_test.go b/src/net/interface_test.go index da54a660e5c..5590b062627 100644 --- a/src/net/interface_test.go +++ b/src/net/interface_test.go @@ -300,6 +300,7 @@ func checkMulticastStats(ifStats *ifStats, uniStats, multiStats *routeStats) err } func BenchmarkInterfaces(b *testing.B) { + b.ReportAllocs() testHookUninstaller.Do(uninstallTestHooks) for i := 0; i < b.N; i++ { @@ -310,6 +311,7 @@ func BenchmarkInterfaces(b *testing.B) { } func BenchmarkInterfaceByIndex(b *testing.B) { + b.ReportAllocs() testHookUninstaller.Do(uninstallTestHooks) ifi := loopbackInterface() @@ -324,6 +326,7 @@ func BenchmarkInterfaceByIndex(b *testing.B) { } func BenchmarkInterfaceByName(b *testing.B) { + b.ReportAllocs() testHookUninstaller.Do(uninstallTestHooks) ifi := loopbackInterface() @@ -338,6 +341,7 @@ func BenchmarkInterfaceByName(b *testing.B) { } func BenchmarkInterfaceAddrs(b *testing.B) { + b.ReportAllocs() testHookUninstaller.Do(uninstallTestHooks) for i := 0; i < b.N; i++ { @@ -348,6 +352,7 @@ func BenchmarkInterfaceAddrs(b *testing.B) { } func BenchmarkInterfacesAndAddrs(b *testing.B) { + b.ReportAllocs() testHookUninstaller.Do(uninstallTestHooks) ifi := loopbackInterface() @@ -362,6 +367,7 @@ func BenchmarkInterfacesAndAddrs(b *testing.B) { } func BenchmarkInterfacesAndMulticastAddrs(b *testing.B) { + b.ReportAllocs() testHookUninstaller.Do(uninstallTestHooks) ifi := loopbackInterface() diff --git a/src/syscall/netlink_linux.go b/src/syscall/netlink_linux.go index e976c70ef16..a503a074400 100644 --- a/src/syscall/netlink_linux.go +++ b/src/syscall/netlink_linux.go @@ -6,7 +6,10 @@ package syscall -import "unsafe" +import ( + "sync" + "unsafe" +) // Round the length of a netlink message up to align it properly. func nlmAlignOf(msglen int) int { @@ -47,6 +50,11 @@ func newNetlinkRouteRequest(proto, seq, family int) []byte { return rr.toWireFormat() } +var pageBufPool = &sync.Pool{New: func() any { + b := make([]byte, Getpagesize()) + return &b +}} + // NetlinkRIB returns routing information base, as known as RIB, which // consists of network facility information, states and parameters. func NetlinkRIB(proto, family int) ([]byte, error) { @@ -72,10 +80,12 @@ func NetlinkRIB(proto, family int) ([]byte, error) { return nil, EINVAL } var tab []byte - rbNew := make([]byte, Getpagesize()) + + rbNew := pageBufPool.Get().(*[]byte) + defer pageBufPool.Put(rbNew) done: for { - rb := rbNew + rb := *rbNew nr, _, err := Recvfrom(s, rb, 0) if err != nil { return nil, err