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path: root/src/runtime/runtime2.go
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2019-10-28runtime: fix dumpgoroutine() to deal with open-coded defersDan Scales
_defer.fn can be nil, so we need to add a check when dumping _defer.fn.fn. Fixes #35172 Change-Id: Ic1138be5ec9dce915a87467cfa51ff83acc6e3a9 Reviewed-on: https://go-review.googlesource.com/c/go/+/203697 Run-TryBot: Dan Scales <danscales@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2019-10-25runtime: only shrink stacks at synchronous safe pointsAustin Clements
We're about to introduce asynchronous safe points, where we won't have precise pointer maps for all stack frames. That's okay for scanning the stack (conservatively), but not for shrinking the stack. Hence, this CL prepares for this by only shrinking the stack as part of the stack scan if the goroutine is stopped at a synchronous safe point. Otherwise, it queues up the stack shrink for the next synchronous safe point. We already have one condition under which we can't shrink the stack for very similar reasons: syscalls. Currently, we just give up on shrinking the stack if it's in a syscall. But with this mechanism, we defer that stack shrink until the next synchronous safe point. For #10958, #24543. Change-Id: Ifa1dec6f33fdf30f9067be2ce3f7ab8a7f62ce38 Reviewed-on: https://go-review.googlesource.com/c/go/+/201438 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-25runtime: make copystack/sudog synchronization more explicitAustin Clements
When we copy a stack of a goroutine blocked in a channel operation, we have to be very careful because other goroutines may be writing to that goroutine's stack. To handle this, stack copying acquires the locks for the channels a goroutine is waiting on. One complication is that stack growth may happen while a goroutine holds these locks, in which case stack copying must *not* acquire these locks because that would self-deadlock. Currently, stack growth never acquires these locks because stack growth only happens when a goroutine is running, which means it's either not blocking on a channel or it's holding the channel locks already. Stack shrinking always acquires these locks because shrinking happens asynchronously, so the goroutine is never running, so there are either no locks or they've been released by the goroutine. However, we're about to change when stack shrinking can happen, which is going to break the current rules. Rather than find a new way to derive whether to acquire these locks or not, this CL simply adds a flag to the g struct that indicates that stack copying should acquire channel locks. This flag is set while the goroutine is blocked on a channel op. For #10958, #24543. Change-Id: Ia2ac8831b1bfda98d39bb30285e144c4f7eaf9ab Reviewed-on: https://go-review.googlesource.com/c/go/+/172982 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2019-10-25runtime: remove g.gcscanvalidAustin Clements
Currently, gcscanvalid is used to resolve a race between attempts to scan a stack. Now that there's a clear owner of the stack scan operation, there's no longer any danger of racing or attempting to scan a stack more than once, so this CL eliminates gcscanvalid. I double-checked my reasoning by first adding a throw if gcscanvalid was set in scanstack and verifying that all.bash still passed. For #10958, #24543. Fixes #24363. Change-Id: I76794a5fcda325ed7cfc2b545e2a839b8b3bc713 Reviewed-on: https://go-review.googlesource.com/c/go/+/201139 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-25runtime: remove old stack scanning codeAustin Clements
This removes scang and preemptscan, since the stack scanning code now uses suspendG. For #10958, #24543. Change-Id: Ic868bf5d6dcce40662a82cb27bb996cb74d0720e Reviewed-on: https://go-review.googlesource.com/c/go/+/201138 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-25runtime: add general suspendG/resumeGAustin Clements
Currently, the process of suspending a goroutine is tied to stack scanning. In preparation for non-cooperative preemption, this CL abstracts this into general purpose suspendG/resumeG functions. suspendG and resumeG closely follow the existing scang and restartg functions with one exception: the addition of a _Gpreempted status. Currently, preemption tasks (stack scanning) are carried out by the target goroutine if it's in _Grunning. In this new approach, the task is always carried out by the goroutine that called suspendG. Thus, we need a reliable way to drive the target goroutine out of _Grunning until the requesting goroutine is ready to resume it. The new _Gpreempted state provides the handshake: when a runnable goroutine responds to a preemption request, it now parks itself and enters _Gpreempted. The requesting goroutine races to put it in _Gwaiting, which gives it ownership, but also the responsibility to start it again. This CL adds several TODOs about improving the synchronization on the G status. The existing code already has these problems; we're just taking note of them. The next CL will remove the now-dead scang and preemptscan. For #10958, #24543. Change-Id: I16dbf87bea9d50399cc86719c156f48e67198f16 Reviewed-on: https://go-review.googlesource.com/c/go/+/201137 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-25runtime: ensure _Grunning Gs have a valid g.m and g.m.pAustin Clements
We already claim on the documentation for _Grunning that this is case, but execute transitions to _Grunning before assigning g.m. Fix this and make the documentation even more explicit. For #10958, #24543, but also a good cleanup. Change-Id: I1eb0108e7762f55cfb0282aca624af1c0a15fe56 Reviewed-on: https://go-review.googlesource.com/c/go/+/201440 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-24cmd/compile, cmd/link, runtime: make defers low-cost through inline code and ↵Dan Scales
extra funcdata Generate inline code at defer time to save the args of defer calls to unique (autotmp) stack slots, and generate inline code at exit time to check which defer calls were made and make the associated function/method/interface calls. We remember that a particular defer statement was reached by storing in the deferBits variable (always stored on the stack). At exit time, we check the bits of the deferBits variable to determine which defer function calls to make (in reverse order). These low-cost defers are only used for functions where no defers appear in loops. In addition, we don't do these low-cost defers if there are too many defer statements or too many exits in a function (to limit code increase). When a function uses open-coded defers, we produce extra FUNCDATA_OpenCodedDeferInfo information that specifies the number of defers, and for each defer, the stack slots where the closure and associated args have been stored. The funcdata also includes the location of the deferBits variable. Therefore, for panics, we can use this funcdata to determine exactly which defers are active, and call the appropriate functions/methods/closures with the correct arguments for each active defer. In order to unwind the stack correctly after a recover(), we need to add an extra code segment to functions with open-coded defers that simply calls deferreturn() and returns. This segment is not reachable by the normal function, but is returned to by the runtime during recovery. We set the liveness information of this deferreturn() to be the same as the liveness at the first function call during the last defer exit code (so all return values and all stack slots needed by the defer calls will be live). I needed to increase the stackguard constant from 880 to 896, because of a small amount of new code in deferreturn(). The -N flag disables open-coded defers. '-d defer' prints out the kind of defer being used at each defer statement (heap-allocated, stack-allocated, or open-coded). Cost of defer statement [ go test -run NONE -bench BenchmarkDefer$ runtime ] With normal (stack-allocated) defers only: 35.4 ns/op With open-coded defers: 5.6 ns/op Cost of function call alone (remove defer keyword): 4.4 ns/op Text size increase (including funcdata) for go binary without/with open-coded defers: 0.09% The average size increase (including funcdata) for only the functions that use open-coded defers is 1.1%. The cost of a panic followed by a recover got noticeably slower, since panic processing now requires a scan of the stack for open-coded defer frames. This scan is required, even if no frames are using open-coded defers: Cost of panic and recover [ go test -run NONE -bench BenchmarkPanicRecover runtime ] Without open-coded defers: 62.0 ns/op With open-coded defers: 255 ns/op A CGO Go-to-C-to-Go benchmark got noticeably faster because of open-coded defers: CGO Go-to-C-to-Go benchmark [cd misc/cgo/test; go test -run NONE -bench BenchmarkCGoCallback ] Without open-coded defers: 443 ns/op With open-coded defers: 347 ns/op Updates #14939 (defer performance) Updates #34481 (design doc) Change-Id: I63b1a60d1ebf28126f55ee9fd7ecffe9cb23d1ff Reviewed-on: https://go-review.googlesource.com/c/go/+/202340 Reviewed-by: Austin Clements <austin@google.com>
2019-10-23runtime: add race detector support for new timersIan Lance Taylor
Since the new timers run on g0, which does not have a race context, we add a race context field to the P, and use that for timer functions. This works since all timer functions are in the standard library. Updates #27707 Change-Id: I8a5b727b4ddc8ca6fc60eb6d6f5e9819245e395b Reviewed-on: https://go-review.googlesource.com/c/go/+/171882 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2019-10-22runtime: add new modtimer functionIan Lance Taylor
This adds a new field to P, adjustTimers, that tells the P that one of its existing timers was modified to be earlier, and that it therefore needs to resort them. Updates #27707 Change-Id: I4c5f5b51ed116f1d898d3f87cdddfa1b552337f8 Reviewed-on: https://go-review.googlesource.com/c/go/+/171832 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2019-10-21runtime: initial scheduler changes for timers on P'sIan Lance Taylor
Add support to the main scheduler loop for handling timers on P's. This is not used yet, as timers are not yet put on P's. Updates #6239 Updates #27707 Change-Id: I6a359df408629f333a9232142ce19e8be8496dae Reviewed-on: https://go-review.googlesource.com/c/go/+/171826 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2019-10-16Revert "cmd/compile, cmd/link, runtime: make defers low-cost through inline ↵Bryan C. Mills
code and extra funcdata" This reverts CL 190098. Reason for revert: broke several builders. Change-Id: I69161352f9ded02537d8815f259c4d391edd9220 Reviewed-on: https://go-review.googlesource.com/c/go/+/201519 Run-TryBot: Bryan C. Mills <bcmills@google.com> Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Dan Scales <danscales@google.com>
2019-10-16cmd/compile, cmd/link, runtime: make defers low-cost through inline code and ↵Dan Scales
extra funcdata Generate inline code at defer time to save the args of defer calls to unique (autotmp) stack slots, and generate inline code at exit time to check which defer calls were made and make the associated function/method/interface calls. We remember that a particular defer statement was reached by storing in the deferBits variable (always stored on the stack). At exit time, we check the bits of the deferBits variable to determine which defer function calls to make (in reverse order). These low-cost defers are only used for functions where no defers appear in loops. In addition, we don't do these low-cost defers if there are too many defer statements or too many exits in a function (to limit code increase). When a function uses open-coded defers, we produce extra FUNCDATA_OpenCodedDeferInfo information that specifies the number of defers, and for each defer, the stack slots where the closure and associated args have been stored. The funcdata also includes the location of the deferBits variable. Therefore, for panics, we can use this funcdata to determine exactly which defers are active, and call the appropriate functions/methods/closures with the correct arguments for each active defer. In order to unwind the stack correctly after a recover(), we need to add an extra code segment to functions with open-coded defers that simply calls deferreturn() and returns. This segment is not reachable by the normal function, but is returned to by the runtime during recovery. We set the liveness information of this deferreturn() to be the same as the liveness at the first function call during the last defer exit code (so all return values and all stack slots needed by the defer calls will be live). I needed to increase the stackguard constant from 880 to 896, because of a small amount of new code in deferreturn(). The -N flag disables open-coded defers. '-d defer' prints out the kind of defer being used at each defer statement (heap-allocated, stack-allocated, or open-coded). Cost of defer statement [ go test -run NONE -bench BenchmarkDefer$ runtime ] With normal (stack-allocated) defers only: 35.4 ns/op With open-coded defers: 5.6 ns/op Cost of function call alone (remove defer keyword): 4.4 ns/op Text size increase (including funcdata) for go cmd without/with open-coded defers: 0.09% The average size increase (including funcdata) for only the functions that use open-coded defers is 1.1%. The cost of a panic followed by a recover got noticeably slower, since panic processing now requires a scan of the stack for open-coded defer frames. This scan is required, even if no frames are using open-coded defers: Cost of panic and recover [ go test -run NONE -bench BenchmarkPanicRecover runtime ] Without open-coded defers: 62.0 ns/op With open-coded defers: 255 ns/op A CGO Go-to-C-to-Go benchmark got noticeably faster because of open-coded defers: CGO Go-to-C-to-Go benchmark [cd misc/cgo/test; go test -run NONE -bench BenchmarkCGoCallback ] Without open-coded defers: 443 ns/op With open-coded defers: 347 ns/op Updates #14939 (defer performance) Updates #34481 (design doc) Change-Id: I51a389860b9676cfa1b84722f5fb84d3c4ee9e28 Reviewed-on: https://go-review.googlesource.com/c/go/+/190098 Reviewed-by: Austin Clements <austin@google.com>
2019-10-10all: remove nacl (part 3, more amd64p32)Brad Fitzpatrick
Part 1: CL 199499 (GOOS nacl) Part 2: CL 200077 (amd64p32 files, toolchain) Part 3: stuff that arguably should've been part of Part 2, but I forgot one of my grep patterns when splitting the original CL up into two parts. This one might also have interesting stuff to resurrect for any future x32 ABI support. Updates #30439 Change-Id: I2b4143374a253a003666f3c69e776b7e456bdb9c Reviewed-on: https://go-review.googlesource.com/c/go/+/200318 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-09-24runtime: update runtime2.go itab comments about sync structSean Chen
`cmd/compile/internal/gc/reflect.go:/^func.dumptypestructs` was modified many times, now is `cmd/compile/internal/gc/reflect.go:/^func.dumptabs` Change-Id: Ie949a5bee7878c998591468a04f67a8a70c61da7 GitHub-Last-Rev: 9ecc26985ef18c8e870649b46419db0a9c72054f GitHub-Pull-Request: golang/go#34489 Reviewed-on: https://go-review.googlesource.com/c/go/+/197037 Reviewed-by: Keith Randall <khr@golang.org>
2019-06-10Revert "Revert "cmd/compile,runtime: allocate defer records on the stack""Keith Randall
This reverts CL 180761 Reason for revert: Reinstate the stack-allocated defer CL. There was nothing wrong with the CL proper, but stack allocation of defers exposed two other issues. Issue #32477: Fix has been submitted as CL 181258. Issue #32498: Possible fix is CL 181377 (not submitted yet). Change-Id: I32b3365d5026600069291b068bbba6cb15295eb3 Reviewed-on: https://go-review.googlesource.com/c/go/+/181378 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-06-05Revert "cmd/compile,runtime: allocate defer records on the stack"Keith Randall
This reverts commit fff4f599fe1c21e411a99de5c9b3777d06ce0ce6. Reason for revert: Seems to still have issues around GC. Fixes #32452 Change-Id: Ibe7af629f9ad6a3d5312acd7b066123f484da7f0 Reviewed-on: https://go-review.googlesource.com/c/go/+/180761 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2019-06-04cmd/compile,runtime: allocate defer records on the stackKeith Randall
When a defer is executed at most once in a function body, we can allocate the defer record for it on the stack instead of on the heap. This should make defers like this (which are very common) faster. This optimization applies to 363 out of the 370 static defer sites in the cmd/go binary. name old time/op new time/op delta Defer-4 52.2ns ± 5% 36.2ns ± 3% -30.70% (p=0.000 n=10+10) Fixes #6980 Update #14939 Change-Id: I697109dd7aeef9e97a9eeba2ef65ff53d3ee1004 Reviewed-on: https://go-review.googlesource.com/c/go/+/171758 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2019-05-17runtime: remove redundant "//"Joey
Change-Id: I44af6cd8baa8fcd2a666429467fae4bed5f21fa0 GitHub-Last-Rev: d0c9722f082114b356de55fc79ce138ede019636 GitHub-Pull-Request: golang/go#32052 Reviewed-on: https://go-review.googlesource.com/c/go/+/177277 Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
2019-05-13runtime: resolve latent function type TODOTamir Duberstein
This was left over from the C->Go transition. Change-Id: I52494af3d49a388dc45b57210ba68292ae01cf84 Reviewed-on: https://go-review.googlesource.com/c/go/+/176897 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2019-05-09runtime: add background scavengerMichael Anthony Knyszek
This change adds a background scavenging goroutine whose pacing is determined when the heap goal changes. The scavenger is paced to use at most 1% of the mutator's time for most systems. Furthermore, the scavenger's pacing is computed based on the estimated number of scavengable huge pages to take advantage of optimizations provided by the OS. The purpose of this scavenger is to deal with a shrinking heap: if the heap goal is falling over time, the scavenger should kick in and start returning free pages from the heap to the OS. Also, now that we have a pacing system, the credit system used by scavengeLocked has become redundant. Replace it with a mechanism which only scavenges on the allocation path if it makes sense to do so with respect to the new pacing system. Fixes #30333. Change-Id: I6203f8dc84affb26c3ab04528889dd9663530edc Reviewed-on: https://go-review.googlesource.com/c/go/+/142960 Run-TryBot: Michael Knyszek <mknyszek@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2019-04-25runtime: document P statusesAustin Clements
We're about to change some of these rules, so it's about time we wrote them down! For #10958, #24543. Change-Id: I3efce0c44b53bfb6f31ce2d299809b2b4eb329f0 Reviewed-on: https://go-review.googlesource.com/c/go/+/172857 Reviewed-by: Russ Cox <rsc@golang.org>
2019-04-15runtime: remove some unused fields in m and pAustin Clements
Change-Id: Ie0171f48aaf48d8399ef578f95352445741d83a9 Reviewed-on: https://go-review.googlesource.com/c/go/+/171773 Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-04-11runtime: note about improved _Gscan bit handlingAustin Clements
Change-Id: I8de5aa64a24e77e0ef876918fcace7668769ebc2 Reviewed-on: https://go-review.googlesource.com/c/go/+/171022 Reviewed-by: Michael Knyszek <mknyszek@google.com>
2019-04-04runtime: ring buffer for binary debug loggingAustin Clements
This adds an internal runtime debug log. It uses per-M time-stamped ring buffers of binary log records. On panic, these buffers are collected, interleaved, and printed. The entry-point to the debug log is a new "dlog" function. dlog is designed so it can be used even from very constrained corners of the runtime such as signal handlers or inside the write barrier. The facility is only enabled if the debuglog build tag is set. Otherwise, it compiles away to a no-op implementation. The debug log format is also designed so it would be reasonable to decode from a core dump, though this hasn't been implemented. Change-Id: I6e2737c286358e97a0d8091826498070b95b66a3 Reviewed-on: https://go-review.googlesource.com/c/go/+/157997 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2019-03-29runtime: rename p racectx field to raceprocctxIan Lance Taylor
Both g and p had a racectx field, but they held different kinds of values. The g field held ThreadState values while the p field held Processor values (to use the names used in the C++ code in the compiler_rt support library). Rename the p field to raceprocctx to reduce potential confusion. Change-Id: Iefba0e259d240171e973054c452c3c15bf3f8f8f Reviewed-on: https://go-review.googlesource.com/c/go/+/169960 Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-01-08runtime: make FuncForPC return the innermost inlined frameKeith Randall
Returning the innermost frame instead of the outermost makes code that walks the results of runtime.Caller{,s} still work correctly in the presence of mid-stack inlining. Fixes #29582 Change-Id: I2392e3dd5636eb8c6f58620a61cef2194fe660a7 Reviewed-on: https://go-review.googlesource.com/c/156364 Run-TryBot: Keith Randall <khr@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-11-14runtime: make processor capability variable naming platform specificMartin Möhrmann
The current support_XXX variables are specific for the amd64 and 386 platforms. Prefix processor capability variables by architecture to have a consistent naming scheme and avoid reuse of the existing variables for new platforms. This also aligns naming of runtime variables closer with internal/cpu processor capability variable names. Change-Id: I3eabb29a03874678851376185d3a62e73c1aff1d Reviewed-on: https://go-review.googlesource.com/c/91435 Run-TryBot: Martin Möhrmann <martisch@uos.de> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2018-11-10runtime: ensure m.p is never staleNikhil Benesch
When a goroutine enters a syscall, its M unwires from its P to allow the P to be retaken by another M if the syscall is slow. The M retains a reference to its old P, however, so that if its old P has not been retaken when the syscall returns, it can quickly reacquire that P. The implementation, however, was confusing, as it left the reference to the potentially-retaken P in m.p, which implied that the P was still wired. Make the code clearer by enforcing the invariant that m.p is never stale. entersyscall now moves m.p to m.oldp and sets m.p to 0; exitsyscall does the reverse, provided m.oldp has not been retaken. With this scheme in place, the issue described in #27660 (assertion failures in the race detector) would have resulted in a clean segfault instead of silently corrupting memory. Change-Id: Ib3e03623ebed4f410e852a716919fe4538858f0a Reviewed-on: https://go-review.googlesource.com/c/148899 Run-TryBot: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-10-03runtime: on a signal, set traceback address to a deferreturn callKeith Randall
When a function triggers a signal (like a segfault which translates to a nil pointer exception) during execution, a sigpanic handler is just below it on the stack. The function itself did not stop at a safepoint, so we have to figure out what safepoint we should use to scan its stack frame. Previously we used the site of the most recent defer to get the live variables at the signal site. That answer is not quite correct, as explained in #27518. Instead, use the site of a deferreturn call. It has all the right variables marked as live (no args, all the return values, except those that escape to the heap, in which case the corresponding PAUTOHEAP variables will be live instead). This CL requires stack objects, so that all the local variables and args referenced by the deferred closures keep the right variables alive. Fixes #27518 Change-Id: Id45d8a8666759986c203181090b962e2981e48ca Reviewed-on: https://go-review.googlesource.com/c/134637 Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-10-02runtime: eliminate gchelper mechanismAustin Clements
Now that we do no mark work during mark termination, we no longer need the gchelper mechanism. Updates #26903. Updates #17503. Change-Id: Ie94e5c0f918cfa047e88cae1028fece106955c1b Reviewed-on: https://go-review.googlesource.com/c/134785 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rick Hudson <rlh@golang.org>
2018-10-02runtime: support disabling goroutine scheduling by classAustin Clements
This adds support for disabling the scheduling of user goroutines while allowing system goroutines like the garbage collector to continue running. User goroutines pass through the usual state transitions, but if we attempt to actually schedule one, it will get put on a deferred scheduling list. Updates #26903. This is preparation for unifying STW GC and concurrent GC. Updates #25578. This same mechanism can form the basis for disabling all but a single user goroutine for the purposes of debugger function call injection. Change-Id: Ib72a808e00c25613fe6982f5528160d3de3dbbc6 Reviewed-on: https://go-review.googlesource.com/c/134779 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rick Hudson <rlh@golang.org>
2018-08-26internal/bytealg: replace use of runtime.support_sse2 with cpu.X86.HasSSE2Martin Möhrmann
This makes the runtime.support_sse2 variable unused so it is removed in this CL too. Change-Id: Ia8b9ffee7ac97128179f74ef244b10315e44c234 Reviewed-on: https://go-review.googlesource.com/131455 Run-TryBot: Martin Möhrmann <moehrmann@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-08-24runtime: replace sys.CacheLineSize by corresponding internal/cpu const and varsMartin Möhrmann
sys here is runtime/internal/sys. Replace uses of sys.CacheLineSize for padding by cpu.CacheLinePad or cpu.CacheLinePadSize. Replace other uses of sys.CacheLineSize by cpu.CacheLineSize. Remove now unused sys.CacheLineSize. Updates #25203 Change-Id: I1daf410fe8f6c0493471c2ceccb9ca0a5a75ed8f Reviewed-on: https://go-review.googlesource.com/126601 Run-TryBot: Martin Möhrmann <moehrmann@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-08-24runtime: use internal/cpu variables in assembler codeMartin Möhrmann
Using internal/cpu variables has the benefit of avoiding false sharing (as those are padded) and allows memory and cache usage for these variables to be shared by multiple packages. Change-Id: I2bf68d03091bf52b466cf689230d5d25d5950037 Reviewed-on: https://go-review.googlesource.com/126599 Run-TryBot: Martin Möhrmann <moehrmann@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2018-08-20runtime: use gList for gfree listsAustin Clements
Change-Id: I3d21587e02264fe5da1cc38d98779facfa09b927 Reviewed-on: https://go-review.googlesource.com/129398 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rick Hudson <rlh@golang.org>
2018-08-20runtime: replace manually managed G dequeues with a typeAustin Clements
There are two manually managed G dequeues. Abstract these both into a shared gQueue type. This also introduces a gList type, which we'll use to replace several manually-managed G lists in follow-up CLs. This makes the code more readable and maintainable. gcFlushBgCredit in particular becomes much easier to follow. It also makes it easier to introduce more G queues in the future. Finally, the gList type clearly distinguishes between lists of Gs and individual Gs; currently both are represented by a *g, which can easily lead to confusion and bugs. Change-Id: Ic7798841b405d311fc8b6aa5a958ffa4c7993c6c Reviewed-on: https://go-review.googlesource.com/129396 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rick Hudson <rlh@golang.org>
2018-08-14runtime: go fmt runtime2.goMartin Möhrmann
Change-Id: I29a6125c9ef285fc365c4e11ab158b79224ae333 Reviewed-on: https://go-review.googlesource.com/126602 Run-TryBot: Martin Möhrmann <moehrmann@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-06-21cmd/compile: improve atomic add intrinsics with ARMv8.1 new instructionWei Xiao
ARMv8.1 has added new instruction (LDADDAL) for atomic memory operations. This CL improves existing atomic add intrinsics with the new instruction. Since the new instruction is only guaranteed to be present after ARMv8.1, we guard its usage with a conditional on CPU feature. Performance result on ARMv8.1 machine: name old time/op new time/op delta Xadd-224 1.05µs ± 6% 0.02µs ± 4% -98.06% (p=0.000 n=10+8) Xadd64-224 1.05µs ± 3% 0.02µs ±13% -98.10% (p=0.000 n=9+10) [Geo mean] 1.05µs 0.02µs -98.08% Performance result on ARMv8.0 machine: name old time/op new time/op delta Xadd-46 538ns ± 1% 541ns ± 1% +0.62% (p=0.000 n=9+9) Xadd64-46 505ns ± 1% 508ns ± 0% +0.48% (p=0.003 n=9+8) [Geo mean] 521ns 524ns +0.55% Change-Id: If4b5d8d0e2d6f84fe1492a4f5de0789910ad0ee9 Reviewed-on: https://go-review.googlesource.com/81877 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-05-25runtime: remove duplicate cpu feature detection on x86Martin Möhrmann
This also allows the GODEBUGCPU options to change the support_* runtime cpu feature variable values. Change-Id: I884c5f03993afc7e3344ff2fd471a2c6cfde43d4 Reviewed-on: https://go-review.googlesource.com/114615 Run-TryBot: Martin Möhrmann <moehrmann@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-05-03runtime: convert g.waitreason from string to uint8Josh Bleecher Snyder
Every time I poke at #14921, the g.waitreason string pointer writes show up. They're not particularly important performance-wise, but it'd be nice to clear the noise away. And it does open up a few extra bytes in the g struct for some future use. This is a re-roll of CL 99078, which was rolled back because of failures on s390x. Those failures were apparently due to an old version of gdb. Change-Id: Icc2c12f449b2934063fd61e272e06237625ed589 Reviewed-on: https://go-review.googlesource.com/111256 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Munday <mike.munday@ibm.com>
2018-04-17cmd/internal/obj/arm, runtime: delete old ARM softfloat codeCherry Zhang
CL 106735 changed to the new softfloat support on GOARM=5. ARM assembly code that uses FP instructions not guarded on GOARM, if any, will break. The easiest way to fix is probably to use Go implementation on GOARM=5, like MOVB runtime·goarm(SB), R11 CMP $5, R11 BEQ arm5 ... FP instructions ... RET arm5: CALL or JMP to Go implementation Change-Id: I52fc76fac9c854ebe7c6c856c365fba35d3f560a Reviewed-on: https://go-review.googlesource.com/107475 Run-TryBot: Cherry Zhang <cherryyz@google.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-04-15runtime: use internal/cpu.X86.HasAVX2 instead of support_avx2Tobias Klauser
After CL 104636 cpu.X86.HasAVX is set early enough that it can be used in runtime·memclrNoHeapPointers. Add an offset to use in assembly and replace the only occurence of support_avx2. Change-Id: Icada62efeb3e24d71251d55623a8a8602364c9a8 Reviewed-on: https://go-review.googlesource.com/106595 Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2018-04-13runtime/traceback: support tracking goroutine ancestor tracebacks with ↵Eric Daniels
GODEBUG="tracebackancestors=N" Currently, collecting a stack trace via runtime.Stack captures the stack for the immediately running goroutines. This change extends those tracebacks to include the tracebacks of their ancestors. This is done with a low memory cost and only utilized when debug option tracebackancestors is set to a value greater than 0. Resolves #22289 Change-Id: I7edacc62b2ee3bd278600c4a21052c351f313f3a Reviewed-on: https://go-review.googlesource.com/70993 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2018-04-11runtime: use internal/cpu instead of support_avxTobias Klauser
After CL 104636 cpu.X86.HasAVX is set early enough that it can be used to determine useAVXmemmove. Use it and remove support_avx. Change-Id: Ib7a627bede2bf96c92362507e742bd833cb42a74 Reviewed-on: https://go-review.googlesource.com/106235 Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-04-10runtime: use internal/cpu in alginitMeng Zhuo
After CL 104636 the feature flags in internal/cpu are initialized before alginit and can now be used for aeshash feature detection. Also remove now unused runtime variables: x86: support_ssse3 support_sse42 support_aes arm64: support_aes Change-Id: I2f64198d91750eaf3c6cf2aac6e9e17615811ec8 Reviewed-on: https://go-review.googlesource.com/106015 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-04-10runtime: remove support_bmi{1,2}Tobias Klauser
The code reading these variables was removed in CL 41476. They are only set but never read now, so remove them. Change-Id: I6b0b8d813e9a3ec2a13586ff92746e00ad1b5bf0 Reviewed-on: https://go-review.googlesource.com/106095 Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-04-04runtime: implement aeshash for arm64 platformMeng Zhuo
Fix #10109 name old time/op new time/op delta Hash5 72.3ns ± 0% 51.5ns ± 0% -28.71% (p=0.000 n=4+5) Hash16 78.8ns ± 0% 48.7ns ± 0% ~ (p=0.079 n=4+5) Hash64 196ns ±25% 73ns ±16% -62.68% (p=0.008 n=5+5) Hash1024 1.57µs ± 0% 0.27µs ± 1% -82.90% (p=0.000 n=5+4) Hash65536 96.5µs ± 0% 14.3µs ± 0% -85.14% (p=0.016 n=5+4) HashStringSpeed 156ns ± 6% 129ns ± 3% -17.56% (p=0.008 n=5+5) HashBytesSpeed 227ns ± 1% 200ns ± 1% -11.98% (p=0.008 n=5+5) HashInt32Speed 116ns ± 2% 102ns ± 0% -11.92% (p=0.016 n=5+4) HashInt64Speed 120ns ± 3% 101ns ± 2% -15.55% (p=0.008 n=5+5) HashStringArraySpeed 342ns ± 0% 306ns ± 2% -10.58% (p=0.008 n=5+5) FastrandHashiter 217ns ± 1% 217ns ± 1% ~ (p=1.000 n=5+5) name old speed new speed delta Hash5 69.1MB/s ± 0% 97.0MB/s ± 0% +40.32% (p=0.008 n=5+5) Hash16 203MB/s ± 0% 329MB/s ± 0% +61.76% (p=0.016 n=4+5) Hash64 332MB/s ±21% 881MB/s ±14% +165.66% (p=0.008 n=5+5) Hash1024 651MB/s ± 0% 3652MB/s ±17% +460.73% (p=0.008 n=5+5) Hash65536 679MB/s ± 0% 4570MB/s ± 0% +572.85% (p=0.016 n=5+4) Change-Id: I573028979f84cf2e0e087951271d5de8865dbf04 Reviewed-on: https://go-review.googlesource.com/89755 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2018-03-15runtime: identify special functions by flag instead of addressKeith Randall
When there are plugins, there may not be a unique copy of runtime functions like goexit, mcall, etc. So identifying them by entry address is problematic. Instead, keep track of each special function using a field in the symbol table. That way, multiple copies of the same runtime function will be treated identically. Fixes #24351 Fixes #23133 Change-Id: Iea3232df8a6af68509769d9ca618f530cc0f84fd Reviewed-on: https://go-review.googlesource.com/100739 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-03-13Revert "runtime: convert g.waitreason from string to uint8"Josh Bleecher Snyder
This reverts commit 4eea887fd477368653f6fcf8ad766030167936e5. Reason for revert: broke s390x build Change-Id: Id6c2b6a7319273c4d21f613d4cdd38b00d49f847 Reviewed-on: https://go-review.googlesource.com/100375 Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>