Currently the pprof package gives almost no guidance for how to use it
and, despite the standard boilerplate used to create CPU and memory
profiles, this boilerplate appears nowhere in the pprof documentation.
Update the pprof package documentation to give the standard
boilerplate in a form people can copy, paste, and tweak. This
boilerplate is based on rsc's 2011 blog post on profiling Go programs
at https://blog.golang.org/profiling-go-programs, which is where I
always go when I need to copy-paste the boilerplate.
Change-Id: I74021e494ea4dcc6b56d6fb5e59829ad4bb7b0be
Reviewed-on: https://go-review.googlesource.com/25182
Reviewed-by: Rick Hudson <rlh@golang.org>
This fixes erroneous handling of the more result parameter of
runtime.Frames.Next.
Fixes#16349.
Change-Id: I4f1c0263dafbb883294b31dbb8922b9d3e650200
Reviewed-on: https://go-review.googlesource.com/24911
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
In the comments for this file there is a reference to gperftools
for more info on pprof. pprof now live on its own repo on github,
and the version in gperftools is deprecated.
Change-Id: I8a188f129534f73edd132ef4e5a2d566e69df7e9
Reviewed-on: https://go-review.googlesource.com/24502
Reviewed-by: Ian Lance Taylor <iant@golang.org>
In order to support pprof for position independent executables, pprof
needs to adjust the PC addresses stored in the profile by the address at
which the program is loaded. The legacy profiling support which we use
already supports recording the GNU/Linux /proc/self/maps data
immediately after the CPU samples, so do that. Also change the pprof
symbolizer to use the information, if available, when looking up
addresses in the Go pcline data.
Fixes#15714.
Change-Id: I4bf679210ef7c51d85cf873c968ce82db8898e3e
Reviewed-on: https://go-review.googlesource.com/23525
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
This should help with debugging failures.
For #15138 and #15477.
Change-Id: I77db2b6375d8b4403d3edf5527899d076291e02c
Reviewed-on: https://go-review.googlesource.com/23134
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
The extra checks provided by newarray are
redundant in these cases.
This shrinks by one frame the call stack expected
by the pprof test.
name old time/op new time/op delta
MakeSlice-8 34.3ns ± 2% 30.5ns ± 3% -11.03% (p=0.000 n=24+22)
GrowSlicePtr-8 134ns ± 2% 129ns ± 3% -3.25% (p=0.000 n=25+24)
Change-Id: Icd828655906b921c732701fd9d61da3fa217b0af
Reviewed-on: https://go-review.googlesource.com/22276
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The test for profiling of channel blocking is timing dependent,
and in particular the blockSelectRecvAsync case can fail on a
slow builder (plan9_arm) when many tests are run in parallel.
The child goroutine sleeps for a fixed period so the parent
can be observed to block in a select call reading from the
child; but if the OS process running the parent goroutine is
delayed long enough, the child may wake again before the
parent has reached the blocking point. By repeating the test
three times, the likelihood of a blocking event is increased.
Fixes#15096
Change-Id: I2ddb9576a83408d06b51ded682bf8e71e53ce59e
Reviewed-on: https://go-review.googlesource.com/21604
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Flaky tests are a distraction and cover up real problems.
File bugs instead and mark them as flaky.
This moves the net/http flaky test flagging mechanism to internal/testenv.
Updates #15156
Updates #15157
Updates #15158
Change-Id: I0e561cd2a09c0dec369cd4ed93bc5a2b40233dfe
Reviewed-on: https://go-review.googlesource.com/21614
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Current runtime.WriteHeapProfile() doesn't print correct
EnableGC. Even if GOGC=off, the result file has below line:
# EnableGC = true
It is hard to print correct status of the variable because of corner
cases e.g. initialization. For avoiding confusion, this commit removes
the print.
Change-Id: Ia792454a6c650bdc50a06fbaff4df7b6330ae08a
Reviewed-on: https://go-review.googlesource.com/18600
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
The tree's pretty inconsistent about single space vs double space
after a period in documentation. Make it consistently a single space,
per earlier decisions. This means contributors won't be confused by
misleading precedence.
This CL doesn't use go/doc to parse. It only addresses // comments.
It was generated with:
$ perl -i -npe 's,^(\s*// .+[a-z]\.) +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.) +([A-Z])')
$ go test go/doc -update
Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7
Reviewed-on: https://go-review.googlesource.com/20022
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Day <djd@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This is a subset of https://golang.org/cl/20022 with only the copyright
header lines, so the next CL will be smaller and more reviewable.
Go policy has been single space after periods in comments for some time.
The copyright header template at:
https://golang.org/doc/contribute.html#copyright
also uses a single space.
Make them all consistent.
Change-Id: Icc26c6b8495c3820da6b171ca96a74701b4a01b0
Reviewed-on: https://go-review.googlesource.com/20111
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This indirectly implements a small fix for runtime/pprof: it used to
look for runtime.gopanic when it should have been looking for
runtime.sigpanic.
Update #11432.
Change-Id: I5e3f5203b2ac5463efd85adf6636e64174aacb1d
Reviewed-on: https://go-review.googlesource.com/19869
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
We used to include panic calls in tracebacks; however, when
runtime.panic was renamed to runtime.gopanic in the conversion of the
runtime to Go, we missed the special case in showframe that includes
panic calls even though they're in package runtime.
Fix the function name check in showframe (and, while we're here, fix
the other check for "runtime.panic" in runtime/pprof). Since the
"runtime.gopanic" name doesn't match what users call panic and hence
isn't very user-friendly, make traceback rewrite it to just "panic".
Updates #5832, #13857. Fixes#14315.
Change-Id: I8059621b41ec043e63d5cfb4cbee479f47f64973
Reviewed-on: https://go-review.googlesource.com/19492
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Currently we run profiling tests for around 200ms in short mode.
However, even on platforms with good profiling, these tests are
inherently flaky, especially on loaded systems like the builders.
To mitigate this, modify the profiling test harness so that if a test
fails in a way that could indicate there just weren't enough samples,
it retries with a longer duration.
This requires some adjustment to the profile checker to distinguish
"fatal" and "retryable" errors. In particular, we no longer consider
it a fatal error to get a profile with zero samples (which we
previously treated as a parse error). We replace this with a retryable
check that the total number of samples is reasonable.
Fixes#13943. Fixes#13871. Fixes#13223.
Change-Id: I9a08664a7e1734c5334b1f3792a56184fe314c4d
Reviewed-on: https://go-review.googlesource.com/18683
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When using c-archive/c-shared, the signal handler for SIGPROF will not
be installed, which means that runtime/pprof.StartCPUProfile won't work.
There is no really good solution here, as the main program may want to
do its own profiling. For now, just document that runtime/pprof doesn't
work as expected, but that it will work if you use Notify to install the
Go signal handler.
Fixes#14043.
Change-Id: I7ff7a01df6ef7f63a7f050aac3674d640a246fb4
Reviewed-on: https://go-review.googlesource.com/18911
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Sigh. Sleeps on FreeBSD also yield the rest of the time slice and
profiling signals are only delivered when a process completes a time
slice (worse, itimer time is only accounted to the process that
completes a time slice). It's less noticeable than the other BSDs
because the default tick rate is 1000Hz, but it's still failing
regularly.
Fixes#13846.
Change-Id: I41bf116bffe46682433b677183f86944d0944ed4
Reviewed-on: https://go-review.googlesource.com/18455
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
Just saw a few dragonfly failures here.
I'm tempted to preemptively add plan9 here too, but I'll wait until
I see it fail.
Change-Id: Ic99fc088dbfd1aa21f509148aee98ccfe7f640bf
Reviewed-on: https://go-review.googlesource.com/18306
Reviewed-by: Russ Cox <rsc@golang.org>
This test triggers a large number of usleep(100)s. linux/arm, openbsd,
and solaris have very poor timer resolution on the builders, so
usleep(100) actually gives up the whole scheduling quantum. On Linux
and OpenBSD (and probably Solaris), profiling signals are only
generated when a process completes a whole scheduling quantum, so this
test often gets zero profiling signals and fails.
Until we figure out what to do about this, skip this test on these
platforms.
Updates #13405.
Change-Id: Ica94e4a8ae7a8df3e5a840504f83ee2ec08727df
Reviewed-on: https://go-review.googlesource.com/18252
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
This test depends on GODEBUG=gcstackbarrierall, which doesn't work on
ppc64.
Updates #13334.
Change-Id: Ie554117b783c4e999387f97dd660484488499d85
Reviewed-on: https://go-review.googlesource.com/17120
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
This adds a test that runs CPU profiling with a high load of stack
barriers and stack barrier insertion/removal operations and checks
that both 1) the runtime doesn't crash and 2) stackBarrier itself
never appears in a profile. Prior to the fix for gentraceback starting
in the middle of stackBarrier, condition 2 often failed.
Change-Id: Ic28860448859029779844c4bf3bb28ca84611e2c
Reviewed-on: https://go-review.googlesource.com/17037
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Move tracing functions from runtime/pprof to the new runtime/trace package.
Fixes#9710
Change-Id: I718bcb2ae3e5959d9f72cab5e6708289e5c8ebd5
Reviewed-on: https://go-review.googlesource.com/12511
Reviewed-by: Russ Cox <rsc@golang.org>
The one in misc/makerelease/makerelease.go is particularly bad and
probably warrants rotating our keys.
I didn't update old weekly notes, and reverted some changes involving
test code for now, since we're late in the Go 1.5 freeze. Otherwise,
the rest are all auto-generated changes, and all manually reviewed.
Change-Id: Ia2753576ab5d64826a167d259f48a2f50508792d
Reviewed-on: https://go-review.googlesource.com/12048
Reviewed-by: Rob Pike <r@golang.org>
There were two issues.
1. Delayed EvGoSysExit could have been emitted during TraceStart,
while it had not yet emitted EvGoInSyscall.
2. Delayed EvGoSysExit could have been emitted during next tracing session.
Fixes#10476Fixes#11262
Change-Id: Iab68eb31cf38eb6eb6eee427f49c5ca0865a8c64
Reviewed-on: https://go-review.googlesource.com/9132
Reviewed-by: Russ Cox <rsc@golang.org>
This is a duplicate of CL 9491.
That CL broke the build due to pprof shortcomings
and was reverted in CL 9565.
CL 9623 fixed pprof, so this can go in again.
Fixes#10659.
Change-Id: If470fc90b3db2ade1d161b4417abd2f5c6c330b8
Reviewed-on: https://go-review.googlesource.com/10212
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This reverts commit c26fc88d56.
This broke pprof. See the comments at 9491.
Change-Id: Ic99ce026e86040c050a9bf0ea3024a1a42274ad1
Reviewed-on: https://go-review.googlesource.com/9565
Reviewed-by: Daniel Morsing <daniel.morsing@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
The heap statistics were only written if asked for a profile with debug > 0,
but that also prints a stack trace for each profile line, which is comparatively
much noisier. The statistics are short enough and separate enough
(they only appear at the end) and useful enough that we can print them
always.
This means that people using -test.memprofile in tests will get a memory
profile with statistics included now. Pprof won't care, but if people care to
look, the numbers will be there.
This avoids the need for hacks like using -memprofilerate=1 to find
the number of allocations.
Change-Id: I10a4f593403d0315aad11b37c6e554b734caa73f
Reviewed-on: https://go-review.googlesource.com/9491
Reviewed-by: David Chase <drchase@google.com>
Just like darwin/arm.
Change-Id: Ic75927bd6457d37cda7dd8279fd9b4cd52edc1d1
Reviewed-on: https://go-review.googlesource.com/8813
Reviewed-by: Minux Ma <minux@golang.org>
1) Large allocation in this test caused crash. This was not
detected by builder because builder runs tests with -test.short.
2) The command "go" for forking doesn't exist in some platforms
including android. This change uses the test binary itself which
is guaranteed to exist.
This change also adds logging of the total samples collected in
TestCPUProfileMultithreaded test that is flaky in android-arm
builder.
Change-Id: I225c6b7877d811edef8b25e7eb00559450640c42
Reviewed-on: https://go-review.googlesource.com/8131
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Channels and sync.Mutex'es allow another goroutine to acquire resource
ahead of an unblocked goroutine. This is good for performance, but
leads to futile wakeups (the unblocked goroutine needs to block again).
Futile wakeups caused user confusion during the very first evaluation
of tracing functionality on a real server (a goroutine as if acquires a mutex
in a loop, while there is no loop in user code).
This change detects futile wakeups on channels and emits a special event
to denote the fact. Later parser finds entire wakeup sequences
(unblock->start->block) and removes them.
sync.Mutex will be supported in a separate change.
Change-Id: Iaaaee9d5c0921afc62b449a97447445030ac19d3
Reviewed-on: https://go-review.googlesource.com/7380
Reviewed-by: Keith Randall <khr@golang.org>
This allows to test goroutine analysis code in runtime/pprof tests.
Also fix a nil-deref crash in goroutine analysis code that happens on runtime/pprof tests.
Change-Id: Id7884aa29f7fe4a8d7042482a86fe434e030461e
Reviewed-on: https://go-review.googlesource.com/7301
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
Augment ProcStart events with OS thread id.
This helps in scheduler locality analysis.
Change-Id: I93fea75d3072cf68de66110d0b59d07101badcb5
Reviewed-on: https://go-review.googlesource.com/7302
Reviewed-by: Keith Randall <khr@golang.org>
Some of the trace stacks are OS-dependent due to OS-specific code
in net package. Check these stacks only on subset of OSes.
Change-Id: If95e4485839f4120fd6395725374c3a2f8706dfc
Reviewed-on: https://go-review.googlesource.com/7300
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Stip uninteresting bottom and top frames from trace stacks.
This makes both binary and json trace files smaller,
and also makes stacks shorter and more readable in the viewer.
Change-Id: Ib9c80ccc280504f0e235f867f53f1d2652c41583
Reviewed-on: https://go-review.googlesource.com/5523
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
Change-Id: I9b08b74214e5a41a7e98866a993b038030a4c073
Reviewed-on: https://go-review.googlesource.com/6251
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Trace command allows to visualize and analyze traces.
Run as:
$ go tool trace binary trace.file
The commands opens web browser with the main page,
which contains links for trace visualization,
blocking profiler, network IO profiler and per-goroutine
traces.
Also move trace parser from runtime/pprof/trace_parser_test.go
to internal/trace/parser.go, so that it can be shared between
tests and the command.
Change-Id: Ic97ed59ad6e4c7e1dc9eca5e979701a2b4aed7cf
Reviewed-on: https://go-review.googlesource.com/3601
Reviewed-by: Andrew Gerrand <adg@golang.org>
The following line in sysFree:
n += (n + memRound) &^ memRound
doubles value of n (n += n).
Which is wrong and can lead to memory corruption.
Fixes#9712
Change-Id: I3c141b71da11e38837c09408cf4f1d22e8f7f36e
Reviewed-on: https://go-review.googlesource.com/3602
Reviewed-by: David du Colombier <0intro@gmail.com>
