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2025-07-11runtime: gofmt after CL 643897 and CL 662455Tobias Klauser
Change-Id: I3103325ebe29509c00b129a317b5708aece575a0 Reviewed-on: https://go-review.googlesource.com/c/go/+/687715 Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Carlos Amedee <carlos@golang.org> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
2025-05-19runtime: rename ncpu to numCPUStartupMichael Pratt
ncpu is the total logical CPU count at startup. It is never updated. For #73193, we will start using updated CPU counts for updated GOMAXPROCS, making the ncpu name a bit ambiguous. Change to a less ambiguous name. While we're at it, give the OS specific lookup functions a common name, so it can be used outside of osinit later. For #73193. Change-Id: I6a6a636cf21cc60de36b211f3c374080849fc667 Reviewed-on: https://go-review.googlesource.com/c/go/+/672277 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Knyszek <mknyszek@google.com> Auto-Submit: Michael Pratt <mpratt@google.com>
2025-05-19runtime: move atoi to internal/runtime/strconvMichael Pratt
Moving to a smaller package allows its use in other internal/runtime packages. This isn't internal/strconvlite since it can't be used directly by strconv. For #73193. Change-Id: I6a6a636c9c8b3f06b5fd6c07fe9dd5a7a37d1429 Reviewed-on: https://go-review.googlesource.com/c/go/+/672697 Reviewed-by: Michael Knyszek <mknyszek@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Auto-Submit: Michael Pratt <mpratt@google.com>
2025-04-03runtime: cleanup M vgetrandom state before dropping PMichael Pratt
When an M is destroyed, we put its vgetrandom state back on the shared list for another M to reuse. This list is simply a slice, so appending to the slice may allocate. Currently this operation is performed in mdestroy, after the P is released, meaning allocation is not allowed. More the cleanup earlier in mdestroy when allocation is still OK. Also add //go:nowritebarrierrec to mdestroy since it runs without a P, which would have caught this bug. Fixes #73141. Change-Id: I6a6a636c3fbf5c6eec09d07a260e39dbb4d2db12 Reviewed-on: https://go-review.googlesource.com/c/go/+/662455 Reviewed-by: Jason Donenfeld <Jason@zx2c4.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Keith Randall <khr@google.com>
2025-03-04runtime: decorate anonymous memory mappingsLénaïc Huard
Leverage the prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, ...) API to name the anonymous memory areas. This API has been introduced in Linux 5.17 to decorate the anonymous memory areas shown in /proc/<pid>/maps. This is already used by glibc. See: * https://sourceware.org/git/?p=glibc.git;a=blob;f=malloc/malloc.c;h=27dfd1eb907f4615b70c70237c42c552bb4f26a8;hb=HEAD#l2434 * https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/setvmaname.c;h=ea93a5ffbebc9e5a7e32a297138f465724b4725f;hb=HEAD#l63 This can be useful when investigating the memory consumption of a multi-language program. On a 100% Go program, pprof profiler can be used to profile the memory consumption of the program. But pprof is only aware of what happens within the Go world. On a multi-language program, there could be a doubt about whether the suspicious extra-memory consumption comes from the Go part or the native part. With this change, the following Go program: package main import ( "fmt" "log" "os" ) /* #include <stdlib.h> void f(void) { (void)malloc(1024*1024*1024); } */ import "C" func main() { C.f() data, err := os.ReadFile("/proc/self/maps") if err != nil { log.Fatal(err) } fmt.Println(string(data)) } produces this output: $ GLIBC_TUNABLES=glibc.mem.decorate_maps=1 ~/doc/devel/open-source/go/bin/go run . 00400000-00402000 r--p 00000000 00:21 28451768 /home/lenaic/.cache/go-build/9f/9f25a17baed5a80d03eb080a2ce2a5ff49c17f9a56e28330f0474a2bb74a30a0-d/test_vma_name 00402000-004a4000 r-xp 00002000 00:21 28451768 /home/lenaic/.cache/go-build/9f/9f25a17baed5a80d03eb080a2ce2a5ff49c17f9a56e28330f0474a2bb74a30a0-d/test_vma_name 004a4000-00574000 r--p 000a4000 00:21 28451768 /home/lenaic/.cache/go-build/9f/9f25a17baed5a80d03eb080a2ce2a5ff49c17f9a56e28330f0474a2bb74a30a0-d/test_vma_name 00574000-00575000 r--p 00173000 00:21 28451768 /home/lenaic/.cache/go-build/9f/9f25a17baed5a80d03eb080a2ce2a5ff49c17f9a56e28330f0474a2bb74a30a0-d/test_vma_name 00575000-00580000 rw-p 00174000 00:21 28451768 /home/lenaic/.cache/go-build/9f/9f25a17baed5a80d03eb080a2ce2a5ff49c17f9a56e28330f0474a2bb74a30a0-d/test_vma_name 00580000-005a4000 rw-p 00000000 00:00 0 2e075000-2e096000 rw-p 00000000 00:00 0 [heap] c000000000-c000400000 rw-p 00000000 00:00 0 [anon: Go: heap] c000400000-c004000000 ---p 00000000 00:00 0 [anon: Go: heap reservation] 777f40000000-777f40021000 rw-p 00000000 00:00 0 [anon: glibc: malloc arena] 777f40021000-777f44000000 ---p 00000000 00:00 0 777f44000000-777f44021000 rw-p 00000000 00:00 0 [anon: glibc: malloc arena] 777f44021000-777f48000000 ---p 00000000 00:00 0 777f48000000-777f48021000 rw-p 00000000 00:00 0 [anon: glibc: malloc arena] 777f48021000-777f4c000000 ---p 00000000 00:00 0 777f4c000000-777f4c021000 rw-p 00000000 00:00 0 [anon: glibc: malloc arena] 777f4c021000-777f50000000 ---p 00000000 00:00 0 777f50000000-777f50021000 rw-p 00000000 00:00 0 [anon: glibc: malloc arena] 777f50021000-777f54000000 ---p 00000000 00:00 0 777f55afb000-777f55afc000 ---p 00000000 00:00 0 777f55afc000-777f562fc000 rw-p 00000000 00:00 0 [anon: glibc: pthread stack: 216378] 777f562fc000-777f562fd000 ---p 00000000 00:00 0 777f562fd000-777f56afd000 rw-p 00000000 00:00 0 [anon: glibc: pthread stack: 216377] 777f56afd000-777f56afe000 ---p 00000000 00:00 0 777f56afe000-777f572fe000 rw-p 00000000 00:00 0 [anon: glibc: pthread stack: 216376] 777f572fe000-777f572ff000 ---p 00000000 00:00 0 777f572ff000-777f57aff000 rw-p 00000000 00:00 0 [anon: glibc: pthread stack: 216375] 777f57aff000-777f57b00000 ---p 00000000 00:00 0 777f57b00000-777f58300000 rw-p 00000000 00:00 0 [anon: glibc: pthread stack: 216374] 777f58300000-777f58400000 rw-p 00000000 00:00 0 [anon: Go: page alloc index] 777f58400000-777f5a400000 rw-p 00000000 00:00 0 [anon: Go: heap index] 777f5a400000-777f6a580000 ---p 00000000 00:00 0 [anon: Go: scavenge index] 777f6a580000-777f6a581000 rw-p 00000000 00:00 0 [anon: Go: scavenge index] 777f6a581000-777f7a400000 ---p 00000000 00:00 0 [anon: Go: scavenge index] 777f7a400000-777f8a580000 ---p 00000000 00:00 0 [anon: Go: page summary] 777f8a580000-777f8a581000 rw-p 00000000 00:00 0 [anon: Go: page alloc] 777f8a581000-777f9c430000 ---p 00000000 00:00 0 [anon: Go: page summary] 777f9c430000-777f9c431000 rw-p 00000000 00:00 0 [anon: Go: page alloc] 777f9c431000-777f9e806000 ---p 00000000 00:00 0 [anon: Go: page summary] 777f9e806000-777f9e807000 rw-p 00000000 00:00 0 [anon: Go: page alloc] 777f9e807000-777f9ec00000 ---p 00000000 00:00 0 [anon: Go: page summary] 777f9ec36000-777f9ecb6000 rw-p 00000000 00:00 0 [anon: Go: immortal metadata] 777f9ecb6000-777f9ecc6000 rw-p 00000000 00:00 0 [anon: Go: gc bits] 777f9ecc6000-777f9ecd6000 rw-p 00000000 00:00 0 [anon: Go: allspans array] 777f9ecd6000-777f9ece7000 rw-p 00000000 00:00 0 [anon: Go: immortal metadata] 777f9ece7000-777f9ed67000 ---p 00000000 00:00 0 [anon: Go: page summary] 777f9ed67000-777f9ed68000 rw-p 00000000 00:00 0 [anon: Go: page alloc] 777f9ed68000-777f9ede7000 ---p 00000000 00:00 0 [anon: Go: page summary] 777f9ede7000-777f9ee07000 rw-p 00000000 00:00 0 [anon: Go: page alloc] 777f9ee07000-777f9ee0a000 rw-p 00000000 00:00 0 [anon: glibc: loader malloc] 777f9ee0a000-777f9ee2e000 r--p 00000000 00:21 48158213 /usr/lib/libc.so.6 777f9ee2e000-777f9ef9f000 r-xp 00024000 00:21 48158213 /usr/lib/libc.so.6 777f9ef9f000-777f9efee000 r--p 00195000 00:21 48158213 /usr/lib/libc.so.6 777f9efee000-777f9eff2000 r--p 001e3000 00:21 48158213 /usr/lib/libc.so.6 777f9eff2000-777f9eff4000 rw-p 001e7000 00:21 48158213 /usr/lib/libc.so.6 777f9eff4000-777f9effc000 rw-p 00000000 00:00 0 777f9effc000-777f9effe000 rw-p 00000000 00:00 0 [anon: glibc: loader malloc] 777f9f00a000-777f9f04a000 rw-p 00000000 00:00 0 [anon: Go: immortal metadata] 777f9f04a000-777f9f04c000 r--p 00000000 00:00 0 [vvar] 777f9f04c000-777f9f04e000 r--p 00000000 00:00 0 [vvar_vclock] 777f9f04e000-777f9f050000 r-xp 00000000 00:00 0 [vdso] 777f9f050000-777f9f051000 r--p 00000000 00:21 48158204 /usr/lib/ld-linux-x86-64.so.2 777f9f051000-777f9f07a000 r-xp 00001000 00:21 48158204 /usr/lib/ld-linux-x86-64.so.2 777f9f07a000-777f9f085000 r--p 0002a000 00:21 48158204 /usr/lib/ld-linux-x86-64.so.2 777f9f085000-777f9f087000 r--p 00034000 00:21 48158204 /usr/lib/ld-linux-x86-64.so.2 777f9f087000-777f9f088000 rw-p 00036000 00:21 48158204 /usr/lib/ld-linux-x86-64.so.2 777f9f088000-777f9f089000 rw-p 00000000 00:00 0 7ffc7bfa7000-7ffc7bfc8000 rw-p 00000000 00:00 0 [stack] ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0 [vsyscall] The anonymous memory areas are now labelled so that we can see which ones have been allocated by the Go runtime versus which ones have been allocated by the glibc. Fixes #71546 Change-Id: I304e8b4dd7f2477a6da794fd44e9a7a5354e4bf4 Reviewed-on: https://go-review.googlesource.com/c/go/+/646095 Auto-Submit: Alan Donovan <adonovan@google.com> Commit-Queue: Alan Donovan <adonovan@google.com> Reviewed-by: Felix Geisendörfer <felix.geisendoerfer@datadoghq.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
2024-11-15runtime: allow futex OSes to use sema-based mutexRhys Hiltner
Implement sema{create,sleep,wakeup} in terms of the futex syscall when available. Split the lock2/unlock2 implementations out of lock_sema.go and lock_futex.go (which they shared with runtime.note) to allow swapping in new implementations of those. Let futex-based platforms use the semaphore-based mutex implementation. Control that via the new "spinbitmutex" GOEXPERMENT value, disabled by default. This lays the groundwork for a "spinbit" mutex implementation; it does not include the new mutex implementation. For #68578. Change-Id: I091289c85124212a87abec7079ecbd9e610b4270 Reviewed-on: https://go-review.googlesource.com/c/go/+/622996 Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-10-07runtime: overwrite startupRand instead of clearing itFilippo Valsorda
AT_RANDOM is unfortunately used by libc before we run (so make sure it's not cleared) but also is available to cgo programs after we did. It would be unfortunate if a cgo program assumed it could use AT_RANDOM but instead found all zeroes there. Change-Id: I82eff34d8cf5a499b439052b7827b8ef7cabc21d Reviewed-on: https://go-review.googlesource.com/c/go/+/608437 Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Daniel McCarney <daniel@binaryparadox.net> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Roland Shoemaker <roland@golang.org>
2024-09-28runtime: use vDSO for getrandom() on linuxJason A. Donenfeld
Linux 6.11 supports calling getrandom() from the vDSO. It operates on a thread-local opaque state allocated with mmap using flags specified by the vDSO. Opaque states are allocated in chunks, ideally ncpu at a time as a hint, rounding up to as many fit in a complete page. On first use, a state is assigned to an m, which owns that state, until the m exits, at which point it is given back to the pool. Performance appears to be quite good: │ sec/op │ sec/op vs base │ Read/4-16 222.45n ± 3% 27.13n ± 6% -87.80% (p=0.000 n=10) │ B/s │ B/s vs base │ Read/4-16 17.15Mi ± 3% 140.61Mi ± 6% +719.82% (p=0.000 n=10) Fixes #69577. Change-Id: Ib6f44e8f2f3940c94d970eaada0eb566ec297dc7 Reviewed-on: https://go-review.googlesource.com/c/go/+/614835 Reviewed-by: Filippo Valsorda <filippo@golang.org> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com> Auto-Submit: Jason Donenfeld <Jason@zx2c4.com> Reviewed-by: Paul Murphy <murp@ibm.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Michael Pratt <mpratt@google.com>
2024-09-26os: ignore SIGSYS in checkPidfdcions
In Android version 11 and earlier, pidfd-related system calls are not allowed by the seccomp policy, which causes crashes due to SIGSYS signals. Fixes #69065 Change-Id: Ib29631639a5cf221ac11b4d82390cb79436b8657 GitHub-Last-Rev: aad6b3b32c81795f86bc4a9e81aad94899daf520 GitHub-Pull-Request: golang/go#69543 Reviewed-on: https://go-review.googlesource.com/c/go/+/614277 Auto-Submit: Ian Lance Taylor <iant@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com>
2024-08-20src: fix typosAlexander Cyon
Fix typos in ~30 files Change-Id: Ie433aea01e7d15944c1e9e103691784876d5c1f9 GitHub-Last-Rev: bbaeb3d1f88a5fa6bbb69607b1bd075f496a7894 GitHub-Pull-Request: golang/go#68964 Reviewed-on: https://go-review.googlesource.com/c/go/+/606955 Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Ian Lance Taylor <iant@google.com>
2024-03-25runtime: migrate internal/atomic to internal/runtimeAndy Pan
For #65355 Change-Id: I65dd090fb99de9b231af2112c5ccb0eb635db2be Reviewed-on: https://go-review.googlesource.com/c/go/+/560155 Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Ibrahim Bazoka <ibrahimbazoka729@gmail.com> Auto-Submit: Emmanuel Odeke <emmanuel@orijtech.com>
2024-03-19runtime: optimize permission changes with mprotectLance Yang
On Linux, both mprotect() and mmap() acquire the mmap_lock (in writer mode), posing scalability challenges. The mmap_lock (formerly called mmap_sem) is a reader/writer lock that controls access to a process's address space; before making changes there (mapping in a new range, for example), the kernel must acquire that lock. Page-fault handling must also acquire mmap_lock (in reader mode) to ensure that the address space doesn't change in surprising ways while a fault is being resolved. A process can have a large address space and many threads running (and incurring page faults) concurrently, turning mmap_lock into a significant bottleneck. While both mmap() and mprotect() are protected by the mmap_lock, the shorter duration of mprotect system call, due to their simpler nature, results in a reduced locking time for the mmap_lock. Change-Id: I7f929544904e31eab34d0d8a9e368abe4de64637 GitHub-Last-Rev: 6f27a216b4fb789181d00316561b44358a118b19 GitHub-Pull-Request: golang/go#65038 Reviewed-on: https://go-review.googlesource.com/c/go/+/554935 Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Mauri de Souza Meneguzzo <mauri870@gmail.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Pratt <mpratt@google.com>
2024-02-21runtime: migrate internal/syscall to internal/runtimeAndy Pan
For #65355 Change-Id: I5fefe30dcb520159de565e61dafc74a740fc8730 Reviewed-on: https://go-review.googlesource.com/c/go/+/559715 Reviewed-by: Michael Pratt <mpratt@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2023-12-05math/rand, math/rand/v2: use ChaCha8 for global randRuss Cox
Move ChaCha8 code into internal/chacha8rand and use it to implement runtime.rand, which is used for the unseeded global source for both math/rand and math/rand/v2. This also affects the calculation of the start point for iteration over very very large maps (when the 32-bit fastrand is not big enough). The benefit is that misuse of the global random number generators in math/rand and math/rand/v2 in contexts where non-predictable randomness is important for security reasons is no longer a security problem, removing a common mistake among programmers who are unaware of the different kinds of randomness. The cost is an extra 304 bytes per thread stored in the m struct plus 2-3ns more per random uint64 due to the more sophisticated algorithm. Using PCG looks like it would cost about the same, although I haven't benchmarked that. Before this, the math/rand and math/rand/v2 global generator was wyrand (https://github.com/wangyi-fudan/wyhash). For math/rand, using wyrand instead of the Mitchell/Reeds/Thompson ALFG was justifiable, since the latter was not any better. But for math/rand/v2, the global generator really should be at least as good as one of the well-studied, specific algorithms provided directly by the package, and it's not. (Wyrand is still reasonable for scheduling and cache decisions.) Good randomness does have a cost: about twice wyrand. Also rationalize the various runtime rand references. goos: linux goarch: amd64 pkg: math/rand/v2 cpu: AMD Ryzen 9 7950X 16-Core Processor │ bbb48afeb7.amd64 │ 5cf807d1ea.amd64 │ │ sec/op │ sec/op vs base │ ChaCha8-32 1.862n ± 2% 1.861n ± 2% ~ (p=0.825 n=20) PCG_DXSM-32 1.471n ± 1% 1.460n ± 2% ~ (p=0.153 n=20) SourceUint64-32 1.636n ± 2% 1.582n ± 1% -3.30% (p=0.000 n=20) GlobalInt64-32 2.087n ± 1% 3.663n ± 1% +75.54% (p=0.000 n=20) GlobalInt64Parallel-32 0.1042n ± 1% 0.2026n ± 1% +94.48% (p=0.000 n=20) GlobalUint64-32 2.263n ± 2% 3.724n ± 1% +64.57% (p=0.000 n=20) GlobalUint64Parallel-32 0.1019n ± 1% 0.1973n ± 1% +93.67% (p=0.000 n=20) Int64-32 1.771n ± 1% 1.774n ± 1% ~ (p=0.449 n=20) Uint64-32 1.863n ± 2% 1.866n ± 1% ~ (p=0.364 n=20) GlobalIntN1000-32 3.134n ± 3% 4.730n ± 2% +50.95% (p=0.000 n=20) IntN1000-32 2.489n ± 1% 2.489n ± 1% ~ (p=0.683 n=20) Int64N1000-32 2.521n ± 1% 2.516n ± 1% ~ (p=0.394 n=20) Int64N1e8-32 2.479n ± 1% 2.478n ± 2% ~ (p=0.743 n=20) Int64N1e9-32 2.530n ± 2% 2.514n ± 2% ~ (p=0.193 n=20) Int64N2e9-32 2.501n ± 1% 2.494n ± 1% ~ (p=0.616 n=20) Int64N1e18-32 3.227n ± 1% 3.205n ± 1% ~ (p=0.101 n=20) Int64N2e18-32 3.647n ± 1% 3.599n ± 1% ~ (p=0.019 n=20) Int64N4e18-32 5.135n ± 1% 5.069n ± 2% ~ (p=0.034 n=20) Int32N1000-32 2.657n ± 1% 2.637n ± 1% ~ (p=0.180 n=20) Int32N1e8-32 2.636n ± 1% 2.636n ± 1% ~ (p=0.763 n=20) Int32N1e9-32 2.660n ± 2% 2.638n ± 1% ~ (p=0.358 n=20) Int32N2e9-32 2.662n ± 2% 2.618n ± 2% ~ (p=0.064 n=20) Float32-32 2.272n ± 2% 2.239n ± 2% ~ (p=0.194 n=20) Float64-32 2.272n ± 1% 2.286n ± 2% ~ (p=0.763 n=20) ExpFloat64-32 3.762n ± 1% 3.744n ± 1% ~ (p=0.171 n=20) NormFloat64-32 3.706n ± 1% 3.655n ± 2% ~ (p=0.066 n=20) Perm3-32 32.93n ± 3% 34.62n ± 1% +5.13% (p=0.000 n=20) Perm30-32 202.9n ± 1% 204.0n ± 1% ~ (p=0.482 n=20) Perm30ViaShuffle-32 115.0n ± 1% 114.9n ± 1% ~ (p=0.358 n=20) ShuffleOverhead-32 112.8n ± 1% 112.7n ± 1% ~ (p=0.692 n=20) Concurrent-32 2.107n ± 0% 3.725n ± 1% +76.75% (p=0.000 n=20) goos: darwin goarch: arm64 pkg: math/rand/v2 │ bbb48afeb7.arm64 │ 5cf807d1ea.arm64 │ │ sec/op │ sec/op vs base │ ChaCha8-8 2.480n ± 0% 2.429n ± 0% -2.04% (p=0.000 n=20) PCG_DXSM-8 2.531n ± 0% 2.530n ± 0% ~ (p=0.877 n=20) SourceUint64-8 2.534n ± 0% 2.533n ± 0% ~ (p=0.732 n=20) GlobalInt64-8 2.172n ± 1% 4.794n ± 0% +120.67% (p=0.000 n=20) GlobalInt64Parallel-8 0.4320n ± 0% 0.9605n ± 0% +122.32% (p=0.000 n=20) GlobalUint64-8 2.182n ± 0% 4.770n ± 0% +118.58% (p=0.000 n=20) GlobalUint64Parallel-8 0.4307n ± 0% 0.9583n ± 0% +122.51% (p=0.000 n=20) Int64-8 4.107n ± 0% 4.104n ± 0% ~ (p=0.416 n=20) Uint64-8 4.080n ± 0% 4.080n ± 0% ~ (p=0.052 n=20) GlobalIntN1000-8 2.814n ± 2% 5.643n ± 0% +100.50% (p=0.000 n=20) IntN1000-8 4.141n ± 0% 4.139n ± 0% ~ (p=0.140 n=20) Int64N1000-8 4.140n ± 0% 4.140n ± 0% ~ (p=0.313 n=20) Int64N1e8-8 4.140n ± 0% 4.139n ± 0% ~ (p=0.103 n=20) Int64N1e9-8 4.139n ± 0% 4.140n ± 0% ~ (p=0.761 n=20) Int64N2e9-8 4.140n ± 0% 4.140n ± 0% ~ (p=0.636 n=20) Int64N1e18-8 5.266n ± 0% 5.326n ± 1% +1.14% (p=0.001 n=20) Int64N2e18-8 6.052n ± 0% 6.167n ± 0% +1.90% (p=0.000 n=20) Int64N4e18-8 8.826n ± 0% 9.051n ± 0% +2.55% (p=0.000 n=20) Int32N1000-8 4.127n ± 0% 4.132n ± 0% +0.12% (p=0.000 n=20) Int32N1e8-8 4.126n ± 0% 4.131n ± 0% +0.12% (p=0.000 n=20) Int32N1e9-8 4.127n ± 0% 4.132n ± 0% +0.12% (p=0.000 n=20) Int32N2e9-8 4.132n ± 0% 4.131n ± 0% ~ (p=0.017 n=20) Float32-8 4.109n ± 0% 4.105n ± 0% ~ (p=0.379 n=20) Float64-8 4.107n ± 0% 4.106n ± 0% ~ (p=0.867 n=20) ExpFloat64-8 5.339n ± 0% 5.383n ± 0% +0.82% (p=0.000 n=20) NormFloat64-8 5.735n ± 0% 5.737n ± 1% ~ (p=0.856 n=20) Perm3-8 26.65n ± 0% 26.80n ± 1% +0.58% (p=0.000 n=20) Perm30-8 194.8n ± 1% 197.0n ± 0% +1.18% (p=0.000 n=20) Perm30ViaShuffle-8 156.6n ± 0% 157.6n ± 1% +0.61% (p=0.000 n=20) ShuffleOverhead-8 124.9n ± 0% 125.5n ± 0% +0.52% (p=0.000 n=20) Concurrent-8 2.434n ± 3% 5.066n ± 0% +108.09% (p=0.000 n=20) goos: linux goarch: 386 pkg: math/rand/v2 cpu: AMD Ryzen 9 7950X 16-Core Processor │ bbb48afeb7.386 │ 5cf807d1ea.386 │ │ sec/op │ sec/op vs base │ ChaCha8-32 11.295n ± 1% 4.748n ± 2% -57.96% (p=0.000 n=20) PCG_DXSM-32 7.693n ± 1% 7.738n ± 2% ~ (p=0.542 n=20) SourceUint64-32 7.658n ± 2% 7.622n ± 2% ~ (p=0.344 n=20) GlobalInt64-32 3.473n ± 2% 7.526n ± 2% +116.73% (p=0.000 n=20) GlobalInt64Parallel-32 0.3198n ± 0% 0.5444n ± 0% +70.22% (p=0.000 n=20) GlobalUint64-32 3.612n ± 0% 7.575n ± 1% +109.69% (p=0.000 n=20) GlobalUint64Parallel-32 0.3168n ± 0% 0.5403n ± 0% +70.51% (p=0.000 n=20) Int64-32 7.673n ± 2% 7.789n ± 1% ~ (p=0.122 n=20) Uint64-32 7.773n ± 1% 7.827n ± 2% ~ (p=0.920 n=20) GlobalIntN1000-32 6.268n ± 1% 9.581n ± 1% +52.87% (p=0.000 n=20) IntN1000-32 10.33n ± 2% 10.45n ± 1% ~ (p=0.233 n=20) Int64N1000-32 10.98n ± 2% 11.01n ± 1% ~ (p=0.401 n=20) Int64N1e8-32 11.19n ± 2% 10.97n ± 1% ~ (p=0.033 n=20) Int64N1e9-32 11.06n ± 1% 11.08n ± 1% ~ (p=0.498 n=20) Int64N2e9-32 11.10n ± 1% 11.01n ± 2% ~ (p=0.995 n=20) Int64N1e18-32 15.23n ± 2% 15.04n ± 1% ~ (p=0.973 n=20) Int64N2e18-32 15.89n ± 1% 15.85n ± 1% ~ (p=0.409 n=20) Int64N4e18-32 18.96n ± 2% 19.34n ± 2% ~ (p=0.048 n=20) Int32N1000-32 10.46n ± 2% 10.44n ± 2% ~ (p=0.480 n=20) Int32N1e8-32 10.46n ± 2% 10.49n ± 2% ~ (p=0.951 n=20) Int32N1e9-32 10.28n ± 2% 10.26n ± 1% ~ (p=0.431 n=20) Int32N2e9-32 10.50n ± 2% 10.44n ± 2% ~ (p=0.249 n=20) Float32-32 13.80n ± 2% 13.80n ± 2% ~ (p=0.751 n=20) Float64-32 23.55n ± 2% 23.87n ± 0% ~ (p=0.408 n=20) ExpFloat64-32 15.36n ± 1% 15.29n ± 2% ~ (p=0.316 n=20) NormFloat64-32 13.57n ± 1% 13.79n ± 1% +1.66% (p=0.005 n=20) Perm3-32 45.70n ± 2% 46.99n ± 2% +2.81% (p=0.001 n=20) Perm30-32 399.0n ± 1% 403.8n ± 1% +1.19% (p=0.006 n=20) Perm30ViaShuffle-32 349.0n ± 1% 350.4n ± 1% ~ (p=0.909 n=20) ShuffleOverhead-32 322.3n ± 1% 323.8n ± 1% ~ (p=0.410 n=20) Concurrent-32 3.331n ± 1% 7.312n ± 1% +119.50% (p=0.000 n=20) For #61716. Change-Id: Ibdddeed85c34d9ae397289dc899e04d4845f9ed2 Reviewed-on: https://go-review.googlesource.com/c/go/+/516860 Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Filippo Valsorda <filippo@golang.org> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2023-11-15runtime/metrics: add STW stopping and total time metricsMichael Pratt
This CL adds four new time histogram metrics: /sched/pauses/stopping/gc:seconds /sched/pauses/stopping/other:seconds /sched/pauses/total/gc:seconds /sched/pauses/total/other:seconds The "stopping" metrics measure the time taken to start a stop-the-world pause. i.e., how long it takes stopTheWorldWithSema to stop all Ps. This can be used to detect STW struggling to preempt Ps. The "total" metrics measure the total duration of a stop-the-world pause, from starting to stop-the-world until the world is started again. This includes the time spent in the "start" phase. The "gc" metrics are used for GC-related STW pauses. The "other" metrics are used for all other STW pauses. All of these metrics start timing in stopTheWorldWithSema only after successfully acquiring sched.lock, thus excluding lock contention on sched.lock. The reasoning behind this is that while waiting on sched.lock the world is not stopped at all (all other Ps can run), so the impact of this contention is primarily limited to the goroutine attempting to stop-the-world. Additionally, we already have some visibility into sched.lock contention via contention profiles (#57071). /sched/pauses/total/gc:seconds is conceptually equivalent to /gc/pauses:seconds, so the latter is marked as deprecated and returns the same histogram as the former. In the implementation, there are a few minor differences: * For both mark and sweep termination stops, /gc/pauses:seconds started timing prior to calling startTheWorldWithSema, thus including lock contention. These details are minor enough, that I do not believe the slight change in reporting will matter. For mark termination stops, moving timing stop into startTheWorldWithSema does have the side effect of requiring moving other GC metric calculations outside of the STW, as they depend on the same end time. Fixes #63340 Change-Id: Iacd0bab11bedab85d3dcfb982361413a7d9c0d05 Reviewed-on: https://go-review.googlesource.com/c/go/+/534161 Reviewed-by: Michael Knyszek <mknyszek@google.com> Auto-Submit: Michael Pratt <mpratt@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2023-10-31runtime: on arm32, detect whether we have sync instructionsKeith Randall
Make the choice of using these instructions dynamic (triggered by cpu feature detection) rather than static (trigered by GOARM setting). if GOARM>=7, we know we have them. For GOARM=5/6, dynamically dispatch based on auxv information. Update #17082 Update #61588 Change-Id: I8a50481d942f62cf36348998a99225d0d242f8af Reviewed-on: https://go-review.googlesource.com/c/go/+/525637 TryBot-Result: Gopher Robot <gobot@golang.org> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Run-TryBot: Keith Randall <khr@google.com> Reviewed-by: Keith Randall <khr@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com>
2023-09-11runtime: avoid staticinit dependency with sigsetAllExitingMatthew Dempsky
Currently, package runtime runs `osinit` before dynamic initialization of package-scope variables; but on GOOS=linux, `osinit` involves mutating `sigsetAllExiting`. This currently works because cmd/compile and gccgo have non-spec-conforming optimizations that statically initialize `sigsetAllExiting`, but disabling that optimization causes `sigsetAllExiting` to be dynamically initialized instead. This in turn causes the mutations in `osinit` to get lost. This CL moves the initialization of `sigsetAllExiting` from `osinit` into its initialization expression, and then removes the special case for continuing to perform the static-initialization optimization for package runtime. Updates #51913. Change-Id: I3be31454277c103372c9701d227dc774b2311dad Reviewed-on: https://go-review.googlesource.com/c/go/+/405549 Auto-Submit: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Heschi Kreinick <heschi@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2023-09-06runtime: clear procid in unminitMichael Pratt
Extra Ms can move between system threads. needm will reinitialize procid (via minit) on the new thread, but leaving a stale procid behind after dropm can be misleading if printing the M early in needm for debugging. Change-Id: I668891971a0baeab31170d1e40a97126416e7379 Reviewed-on: https://go-review.googlesource.com/c/go/+/526118 Reviewed-by: Cherry Mui <cherryyz@google.com> Auto-Submit: Michael Pratt <mpratt@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2023-06-06runtime: implement SUID/SGID protectionsRoland Shoemaker
On Unix platforms, the runtime previously did nothing special when a program was run with either the SUID or SGID bits set. This can be dangerous in certain cases, such as when dumping memory state, or assuming the status of standard i/o file descriptors. Taking cues from glibc, this change implements a set of protections when a binary is run with SUID or SGID bits set (or is SUID/SGID-like). On Linux, whether to enable these protections is determined by whether the AT_SECURE flag is passed in the auxiliary vector. On platforms which have the issetugid syscall (the BSDs, darwin, and Solaris/Illumos), that is used. On the remaining platforms (currently only AIX) we check !(getuid() == geteuid() && getgid == getegid()). Currently when we determine a binary is "tainted" (using the glibc terminology), we implement two specific protections: 1. we check if the file descriptors 0, 1, and 2 are open, and if they are not, we open them, pointing at /dev/null (or fail). 2. we force GOTRACKBACK=none, and generally prevent dumping of trackbacks and registers when a program panics/aborts. In the future we may add additional protections. This change requires implementing issetugid on the platforms which support it, and implementing getuid, geteuid, getgid, and getegid on AIX. Thanks to Vincent Dehors from Synacktiv for reporting this issue. Fixes #60272 Fixes CVE-2023-29403 Change-Id: I73fc93f2b7a8933c192ce3eabbf1db359db7d5fa Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/1878434 Reviewed-by: Damien Neil <dneil@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com> Run-TryBot: Roland Shoemaker <bracewell@google.com> Reviewed-by: Russ Cox <rsc@google.com> Reviewed-on: https://go-review.googlesource.com/c/go/+/501223 Run-TryBot: David Chase <drchase@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-05-20runtime: change fcntl to return two valuesIan Lance Taylor
Separate the result and the errno value, rather than assuming that the result can never be negative. Change-Id: Ib01a70a3d46285aa77e95371cdde74e1504e7c12 Reviewed-on: https://go-review.googlesource.com/c/go/+/496416 Run-TryBot: Ian Lance Taylor <iant@golang.org> Run-TryBot: Ian Lance Taylor <iant@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com> Reviewed-by: Bryan Mills <bcmills@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com>
2023-05-19runtime: emit STW events for all pauses, not just those for the GCMichael Anthony Knyszek
Currently STW events are only emitted for GC STWs. There's little reason why the trace can't contain events for every STW: they're rare so don't take up much space in the trace, yet being able to see when the world was stopped is often critical to debugging certain latency issues, especially when they stem from user-level APIs. This change adds new "kinds" to the EvGCSTWStart event, renames the GCSTW events to just "STW," and lets the parser deal with unknown STW kinds for future backwards compatibility. But, this change must break trace compatibility, so it bumps the trace version to Go 1.21. This change also includes a small cleanup in the trace command, which previously checked for STW events when deciding whether user tasks overlapped with a GC. Looking at the source, I don't see a way for STW events to ever enter the stream that that code looks at, so that condition has been deleted. Change-Id: I9a5dc144092c53e92eb6950e9a5504a790ac00cf Reviewed-on: https://go-review.googlesource.com/c/go/+/494495 Reviewed-by: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Michael Knyszek <mknyszek@google.com>
2023-05-17runtime: consistently define fcntlIan Lance Taylor
Clean up and consolidate on a single consistent definition of fcntl, which takes three int32 arguments and returns either a positive result or a negative errno value. Change-Id: Id9505492712db4b0aab469c6bd15e4fce3c9ff6e Reviewed-on: https://go-review.googlesource.com/c/go/+/495075 Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Ian Lance Taylor <iant@google.com> Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com> Reviewed-by: Michael Pratt <mpratt@google.com>
2023-03-24runtime: add "sigaction" to sigreturn symbol nameMichael Pratt
In order to identify the sigreturn function, gdb looks for "__restore_rt". However because that symbol is sometimes missing from the symbol table, it also performs the same instruction matching as libgcc, but only in symbols containing "sigaction" (it expects sigaction to preceed __restore_rt). To match this heuristic, we add __sigaction to the sigreturn symbol name. Fixes #25218. Change-Id: I09cb231ad23f668d451f31dd5633f782355fc91d Reviewed-on: https://go-review.googlesource.com/c/go/+/479096 Auto-Submit: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com> Run-TryBot: Michael Pratt <mpratt@google.com>
2023-02-16runtime: expose auxv for use by x/sys/cpuBrad Fitzpatrick
Updates #57336 Change-Id: I181885f59bac59360b855d3990326ea2b268bd28 Reviewed-on: https://go-review.googlesource.com/c/go/+/458256 Reviewed-by: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Austin Clements <austin@google.com> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2023-01-28runtime: remove go118UseTimerCreateProfilerKeith Randall
Change-Id: I37b15690fef6ca5354def834b1f6094e133a9fe4 Reviewed-on: https://go-review.googlesource.com/c/go/+/463736 Run-TryBot: Keith Randall <khr@golang.org> Reviewed-by: Rhys Hiltner <rhys@justin.tv> Auto-Submit: Keith Randall <khr@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Keith Randall <khr@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
2022-11-10runtime: retry thread creation on EAGAINIan Lance Taylor
This copies the logic we use in runtime/cgo, when calling pthread_create, into runtime proper, when calling newosproc. We only do this in newosproc, not newosproc0, because in newosproc0 we need a nosplit function literal, and we need to pass arguments to it through newosproc, which is a pain. Also newosproc0 is only called at process startup, when thread creation is less likely to fail anyhow. Fixes #49438 Change-Id: Ia26813952fdbae8aaad5904c9102269900a07ba9 Reviewed-on: https://go-review.googlesource.com/c/go/+/447175 Reviewed-by: Michael Knyszek <mknyszek@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com>
2022-11-10runtime: consolidate some low-level error reportingIan Lance Taylor
Use a single writeErrStr function. Avoid using global variables. Use a single version of some error messages rather than duplicating the messages in OS-specific files. Change-Id: If259fbe78faf797f0a21337d14472160ca03efa0 Reviewed-on: https://go-review.googlesource.com/c/go/+/447055 Run-TryBot: Ian Lance Taylor <iant@golang.org> Run-TryBot: Ian Lance Taylor <iant@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2022-10-26runtime: add missing closing curly brace in runtime corruption error messageBrad Fitzpatrick
(Fixing the most important part of this bug.) Updates #56426 Change-Id: If657ae47a5fe7dacc31d2c487e53e9f2dd5d03bf Reviewed-on: https://go-review.googlesource.com/c/go/+/445695 TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> Auto-Submit: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com> Reviewed-by: Michael Pratt <mpratt@google.com>
2022-10-26runtime: fix a few function names on commentscui fliter
Change-Id: I4be0b1e612dcc21ca6bb7d4395f1c0aa52480759 GitHub-Last-Rev: 032480c4c9ddb2bedea26b01bb80b8a079bfdcf3 GitHub-Pull-Request: golang/go#55993 Reviewed-on: https://go-review.googlesource.com/c/go/+/437518 Reviewed-by: hopehook <hopehook@golangcn.org> Reviewed-by: Keith Randall <khr@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Carlos Amedee <carlos@golang.org> Reviewed-by: Keith Randall <khr@golang.org> Run-TryBot: hopehook <hopehook@golangcn.org>
2022-09-21runtime: treat SI_TKILL like SI_USER on LinuxIan Lance Taylor
On Linux a signal sent using tgkill will have si_code == SI_TKILL, not SI_USER. Treat the two cases the same. Add a Linux-specific test. Change the test to use the C pause function rather than sleeping for a second, as that achieves the same effect. This is a roll forward of CL 431255 which was rolled back in CL 431715. This new version skips flaky tests on more systems, and marks a new method nosplit. Change-Id: Ibf2d3e6fc43d63d0a71afa8fcca6a11fda03f291 Reviewed-on: https://go-review.googlesource.com/c/go/+/432136 Auto-Submit: Ian Lance Taylor <iant@golang.org> Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Bryan Mills <bcmills@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-09-19Revert "runtime: treat SI_TKILL like SI_USER on Linux"Cuong Manh Le
This reverts CL 431255. Reason for revert: breaks darwin-arm and linux-noopt builders. Change-Id: I29332b935cc1e35fa039af3d70465e496361fcc9 Reviewed-on: https://go-review.googlesource.com/c/go/+/431715 Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Bryan Mills <bcmills@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-09-17runtime: treat SI_TKILL like SI_USER on LinuxIan Lance Taylor
On Linux a signal sent using tgkill will have si_code == SI_TKILL, not SI_USER. Treat the two cases the same. Add a Linux-specific test. Change the test to use the C pause function rather than sleeping for a second, as that achieves the same effect. Change-Id: I2a36646aecabcab9ec42ed9a048b07c2ff0a3987 Reviewed-on: https://go-review.googlesource.com/c/go/+/431255 TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com>
2022-08-31runtime: convert mOS.profileTimerValid to internal atomic typeAndy Pan
For #53821 Change-Id: I6ef90867e918d4907baa83c5a811f1f93e8c09a5 Reviewed-on: https://go-review.googlesource.com/c/go/+/426196 Reviewed-by: Michael Knyszek <mknyszek@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Michael Pratt <mpratt@google.com> Run-TryBot: Michael Knyszek <mknyszek@google.com> Reviewed-by: Michael Pratt <mpratt@google.com>
2022-05-19all: gofmt main repoRuss Cox
Excluding vendor and testdata. CL 384268 already reformatted most, but these slipped past. The struct in the doc comment in debug/dwarf/type.go was fixed up by hand to indent the first and last lines as well. For #51082. Change-Id: Iad020f83aafd671ff58238fe491907e85923d0c7 Reviewed-on: https://go-review.googlesource.com/c/go/+/407137 Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Russ Cox <rsc@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com>
2022-04-28runtime: differentiate "user" and "system" throwsMichael Pratt
"User" throws are throws due to some invariant broken by the application. "System" throws are due to some invariant broken by the runtime, environment, etc (i.e., not the fault of the application). This CL sends "user" throws through the new fatal. Currently this function is identical to throw, but with a different name to clearly differentiate the throw type in the stack trace, and hopefully be a bit more clear to users what it means. This CL changes a few categories of throw to fatal: 1. Concurrent map read/write. 2. Deadlock detection. 3. Unlock of unlocked sync.Mutex. 4. Inconsistent results from syscall.AllThreadsSyscall. "Thread exhaustion" and "out of memory" (usually address space full) throws are additional throws that are arguably the fault of user code, but I've left off for now because there is no specific invariant that they have broken to get into these states. For #51485 Change-Id: I713276a6c290fd34a6563e6e9ef378669d74ae32 Reviewed-on: https://go-review.googlesource.com/c/go/+/390420 TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com> Run-TryBot: Michael Pratt <mpratt@google.com>
2022-04-11all: gofmt main repoRuss Cox
[This CL is part of a sequence implementing the proposal #51082. The design doc is at https://go.dev/s/godocfmt-design.] Run the updated gofmt, which reformats doc comments, on the main repository. Vendored files are excluded. For #51082. Change-Id: I7332f099b60f716295fb34719c98c04eb1a85407 Reviewed-on: https://go-review.googlesource.com/c/go/+/384268 Reviewed-by: Jonathan Amsterdam <jba@google.com> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-04-05all: separate doc comment from //go: directivesRuss Cox
A future change to gofmt will rewrite // Doc comment. //go:foo to // Doc comment. // //go:foo Apply that change preemptively to all comments (not necessarily just doc comments). For #51082. Change-Id: Iffe0285418d1e79d34526af3520b415a12203ca9 Reviewed-on: https://go-review.googlesource.com/c/go/+/384260 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-03runtime: remove fallback to pipe on platforms with pipe2Tobias Klauser
On Linux, the minimum required kernel version for Go 1.18 was be changed to 2.6.32, see #45964. The pipe2 syscall was added in 2.6.27. All other platforms already provide the pipe2 syscall in the minimum supported version: - DragonFly BSD added it in version 4.2, see https://www.dragonflybsd.org/release42/ - FreeBSD added it in version 10.0, see https://www.freebsd.org/cgi/man.cgi?pipe(2)#end - NetBSD added it in version 6.0, see https://man.netbsd.org/pipe2.2#HISTORY - OpenBSD added it in version 5.7, see https://man.openbsd.org/pipe.2#HISTORY - Illumos supports it since 2013, see https://www.illumos.org/issues/3714 - Solaris supports it since 11.4 This also allows to remove setNonblock which was only used in the pipe fallback path on these platforms. Change-Id: I1f40d32fd3065d74e22af77b9ff2292b9cf66706 Reviewed-on: https://go-review.googlesource.com/c/go/+/389354 Trust: Tobias Klauser <tobias.klauser@gmail.com> Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-02-15runtime, syscall: reimplement AllThreadsSyscall using only signals.Michael Pratt
In issue 50113, we see that a thread blocked in a system call can result in a hang of AllThreadsSyscall. To resolve this, we must send a signal to these threads to knock them out of the system call long enough to run the per-thread syscall. Stepping back, if we need to send signals anyway, it should be possible to implement this entire mechanism on top of signals. This CL does so, vastly simplifying the mechanism, both as a direct result of newly-unnecessary code as well as some ancillary simplifications to make things simpler to follow. Major changes: * The rest of the mechanism is moved to os_linux.go, with fields in mOS instead of m itself. * 'Fixup' fields and functions are renamed to 'perThreadSyscall' so they are more precise about their purpose. * Rather than getting passed a closure, doAllThreadsSyscall takes the syscall number and arguments. This avoids a lot of hairy behavior: * The closure may potentially only be live in fields in the M, hidden from the GC. Not necessary with no closure. * The need to loan out the race context. A direct RawSyscall6 call does not require any race context. * The closure previously conditionally panicked in strange locations, like a signal handler. Now we simply throw. * All manual fixup synchronization with mPark, sysmon, templateThread, sigqueue, etc is gone. The core approach is much simpler: doAllThreadsSyscall sends a signal to every thread in allm, which executes the system call from the signal handler. We use (SIGRTMIN + 1), aka SIGSETXID, the same signal used by glibc for this purpose. As such, we are careful to only handle this signal on non-cgo binaries. Synchronization with thread creation is a key part of this CL. The comment near the top of doAllThreadsSyscall describes the required synchronization semantics and how they are achieved. Note that current use of allocmLock protects the state mutations of allm that are also protected by sched.lock. allocmLock is used instead of sched.lock simply to avoid holding sched.lock for so long. Fixes #50113 Change-Id: Ic7ea856dc66cf711731540a54996e08fc986ce84 Reviewed-on: https://go-review.googlesource.com/c/go/+/383434 Reviewed-by: Austin Clements <austin@google.com> Trust: Michael Pratt <mpratt@google.com> Run-TryBot: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-02-15runtime: move doAllThreadsSyscall to os_linux.goMichael Pratt
syscall_runtime_doAllThreadsSyscall is only used on Linux. In preparation of a follow-up CL that will modify the function to use other Linux-only functions, move it to os_linux.go with no changes. For #50113. Change-Id: I348b6130038603aa0a917be1f1debbca5a5a073f Reviewed-on: https://go-review.googlesource.com/c/go/+/383996 Trust: Michael Pratt <mpratt@google.com> Reviewed-by: Andrew G. Morgan <agm@google.com> Reviewed-by: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2021-11-02runtime: add padding to Linux kernel structuresRhys Hiltner
Go exchanges siginfo and sigevent structures with the kernel. They contain unions, but Go's use is limited to the first few fields. Pad out the rest so the size Go sees is the same as what the Linux kernel sees. This is a follow-up to CL 342052 which added the sigevent struct without padding, and to CL 353136 which added the padding but with an assertion that confused several type-checkers. It updates the siginfo struct as well so there are no bad examples in the defs_linux_*.go files. Reviewed-on: https://go-review.googlesource.com/c/go/+/353136 Change-Id: I9610632ff0ec43eba91f560536f5441fa907b36f Reviewed-on: https://go-review.googlesource.com/c/go/+/360094 Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com>
2021-10-04Revert "runtime: add padding to Linux kernel structures"Michael Pratt
This reverts commit f0db7eae74ea235e9fbc2598252bfd46c1cc5510. Reason for revert: Breaks linux-386 tests Change-Id: Ia51fbf97460ab52920b67d6db6177ac2d6b0058e Reviewed-on: https://go-review.googlesource.com/c/go/+/353432 Trust: Michael Pratt <mpratt@google.com> Run-TryBot: Michael Pratt <mpratt@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com>
2021-10-04runtime: add padding to Linux kernel structuresRhys Hiltner
Go exchanges siginfo and sigevent structures with the kernel. They contain unions, but Go's use is limited to the first few fields. Pad out the rest so the size Go sees is the same as what the Linux kernel sees. This is a follow-up to CL 342052 which added the sigevent struct without padding. It updates the siginfo struct as well so there are no bad examples in the defs_linux_*.go files. Change-Id: Id991d4a57826677dd7e6cc30ad113fa3b321cddf Reviewed-on: https://go-review.googlesource.com/c/go/+/353136 Run-TryBot: Rhys Hiltner <rhys@justin.tv> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com> Trust: Michael Knyszek <mknyszek@google.com>
2021-09-27runtime: use per-thread profiler for SetCgoTraceback platformsRhys Hiltner
Updates #35057 Change-Id: I61d772a2cbfb27540fb70c14676c68593076ca94 Reviewed-on: https://go-review.googlesource.com/c/go/+/342054 Run-TryBot: Rhys Hiltner <rhys@justin.tv> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com> Trust: Michael Knyszek <mknyszek@google.com>
2021-09-27runtime: profile with per-thread timers on LinuxRhys Hiltner
Using setitimer on Linux to request SIGPROF signal deliveries in proportion to the process's on-CPU time results in under-reporting when the program uses several goroutines in parallel. Linux calculates the process's total CPU spend on a regular basis (often every 4ms); if the process has spent enough CPU time since the last calculation to warrant more than one SIGPROF (usually 10ms for the default sample rate of 100 Hz), the kernel is often able to deliver only one of them. With these common settings, that results in Go CPU profiles being attenuated for programs that use more than 2.5 goroutines in parallel. To avoid in effect overflowing the kernel's process-wide CPU counter, and relying on Linux's typical behavior of having the active thread handle the resulting process-targeted signal, use timer_create to request a timer for each OS thread that the Go runtime manages. Have each timer track the CPU time of a single thread, with the resulting SIGPROF going directly to that thread. To continue tracking CPU time spent on threads that don't interact with the Go runtime (such as those created and used in cgo), keep using setitimer in addition to the new mechanism. When a SIGPROF signal arrives, check whether it's due to setitimer or timer_create and filter as appropriate: If the thread is known to Go (has an M) and has a timer_create timer, ignore SIGPROF signals from setitimer. If the thread is not known to Go (does not have an M), ignore SIGPROF signals that are not from setitimer. Counteract the new bias that per-thread profiling adds against short-lived threads (or those that are only active on occasion for a short time, such as garbage collection workers on mostly-idle systems) by configuring the timers' initial trigger to be from a uniform random distribution between "immediate trigger" and the full requested sample period. Updates #35057 Change-Id: Iab753c4e5101bdc09ef9132eec84a75478e05579 Reviewed-on: https://go-review.googlesource.com/c/go/+/324129 Run-TryBot: Rhys Hiltner <rhys@justin.tv> TryBot-Result: Go Bot <gobot@golang.org> Trust: David Chase <drchase@google.com> Reviewed-by: Michael Pratt <mpratt@google.com>
2021-09-27runtime: allow per-OS changes to unix profilerRhys Hiltner
Updates #35057 Change-Id: I56ea8f4750022847f0866c85e237a2cea40e0ff7 Reviewed-on: https://go-review.googlesource.com/c/go/+/342053 Run-TryBot: Rhys Hiltner <rhys@justin.tv> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com> Trust: Michael Knyszek <mknyszek@google.com>
2021-09-27runtime: add timer_create syscalls for LinuxRhys Hiltner
Updates #35057 Change-Id: Id702b502fa4e4005ba1e450a945bc4420a8a8b8c Reviewed-on: https://go-review.googlesource.com/c/go/+/342052 Run-TryBot: Rhys Hiltner <rhys@justin.tv> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com> Trust: Than McIntosh <thanm@google.com>
2021-06-17[dev.typeparams] runtime: replace uses of runtime/internal/sys.PtrSize with ↵Michael Anthony Knyszek
internal/goarch.PtrSize [generated] [git-generate] cd src/runtime/internal/math gofmt -w -r "sys.PtrSize -> goarch.PtrSize" . goimports -w *.go cd ../.. gofmt -w -r "sys.PtrSize -> goarch.PtrSize" . goimports -w *.go Change-Id: I43491cdd54d2e06d4d04152b3d213851b7d6d423 Reviewed-on: https://go-review.googlesource.com/c/go/+/328337 Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Michael Knyszek <mknyszek@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-05-21[dev.typeparams] runtime: replace funcPC with internal/abi.FuncPCABIInternalCherry Mui
At this point all funcPC references are ABIInternal functions. Replace with the intrinsics. Change-Id: I3ba7e485c83017408749b53f92877d3727a75e27 Reviewed-on: https://go-review.googlesource.com/c/go/+/321954 Trust: Cherry Mui <cherryyz@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-05-21[dev.typeparams] runtime: use internal/abi.FuncPCABI0 to reference ABI0 ↵Cherry Mui
assembly symbols Use FuncPCABI0 to reference ABI0 assembly symbols. Currently, they are referenced using funcPC, which will get the ABI wrapper's address. They don't seem to affect correctness (either the wrapper is harmless, or, on non-AMD64 architectures, not enabled). They should have been converted. This CL does not yet completely eliminate funcPC. But at this point we should be able to replace all remaining uses of funcPC to internal/abi.FuncPCABIInternal. Change-Id: I383a686e11d570f757f185fe46769a42c856ab77 Reviewed-on: https://go-review.googlesource.com/c/go/+/321952 Trust: Cherry Mui <cherryyz@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>