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  1. 30 Oct, 2016 3 commits
  3. 29 Oct, 2016 12 commits
  5. 28 Oct, 2016 25 commits
    • Ian Lance Taylor's avatar
      time: clarify Equal docs · 023556c0
      Ian Lance Taylor authored 
      The docs used to imply that using == would compare Locations, but of
course it just compares Location pointers, which will have unpredictable
results depending on how the pointers are loaded.

Change-Id: I783c1309e476a9616a1c1c290eac713aba3b0b57
Reviewed-on: https://go-review.googlesource.com/32332Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      023556c0
    • Mikio Hara's avatar
      net: use IPv4 reserved address blocks for documentation · 9575c580
      Mikio Hara authored 
      Updates #15228.

Change-Id: Iefdffa146703ee1c04afc2b71d9de1f0a0811f86
Reviewed-on: https://go-review.googlesource.com/32146
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      9575c580
    • Mikio Hara's avatar
      net: deflake TestLookupNonLDH · 69b7fe1a
      Mikio Hara authored 
      Fixes #17623.

Change-Id: I4717e8399f955c9be7ba19108bb0bcc108187c04
Reviewed-on: https://go-review.googlesource.com/32147
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      69b7fe1a
    • Peter Weinberger's avatar
      runtime: ensure elapsed cycles are not negative · a1b6e169
      Peter Weinberger authored 
      On solaris/amd64 sometimes the reported cycle count is negative. Replace
with 0.

Change-Id: I364eea5ca072281245c7ab3afb0bf69adc3a8eae
Reviewed-on: https://go-review.googlesource.com/32258Reviewed-by: 's avatarIan Lance Taylor <iant@golang.org>
      a1b6e169
    • Matthew Dempsky's avatar
      cmd/compile: improve not enough / too many arguments errors · ec5b6406
      Matthew Dempsky authored 
      Use "have" and "want" and multiple lines like other similar error
messages. Also, fix handling of ... and multi-value function calls.

Fixes #17650.

Change-Id: I4850e79c080eac8df3b92a4accf9e470dff63c9a
Reviewed-on: https://go-review.googlesource.com/32261Reviewed-by: 's avatarRobert Griesemer <gri@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
      ec5b6406
    • Austin Clements's avatar
      runtime: fix SP adjustment on amd64p32 · 1bd39e79
      Austin Clements authored 
      On amd64p32, rt0_go attempts to reserve 128 bytes of scratch space on
the stack, but due to a register mixup this ends up being a no-op. Fix
this so we actually reserve the stack space.

Change-Id: I04dbfbeb44f3109528c8ec74e1136bc00d7e1faa
Reviewed-on: https://go-review.googlesource.com/32331
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarIan Lance Taylor <iant@golang.org>
      1bd39e79
    • Austin Clements's avatar
      runtime: disable stack rescanning by default · bd640c88
      Austin Clements authored 
      With the hybrid barrier in place, we can now disable stack rescanning
by default. This commit adds a "gcrescanstacks" GODEBUG variable that
is off by default but can be set to re-enable STW stack rescanning.
The plan is to leave this off but available in Go 1.8 for debugging
and as a fallback.

With this change, worst-case mark termination time at GOMAXPROCS=12
*not* including time spent stopping the world (which is still
unbounded) is reliably under 100 µs, with a 95%ile around 50 µs in
every benchmark I tried (the go1 benchmarks, the x/benchmarks garbage
benchmark, and the gcbench activegs and rpc benchmarks). Including
time spent stopping the world usually adds about 20 µs to total STW
time at GOMAXPROCS=12, but I've seen it add around 150 µs in these
benchmarks when a goroutine takes time to reach a safe point (see
issue #10958) or when stopping the world races with goroutine
switches. At GOMAXPROCS=1, where this isn't an issue, worst case STW
is typically 30 µs.

The go-gcbench activegs benchmark is designed to stress large numbers
of dirty stacks. This commit reduces 95%ile STW time for 500k dirty
stacks by nearly three orders of magnitude, from 150ms to 195µs.

This has little effect on the throughput of the go1 benchmarks or the
x/benchmarks benchmarks.

name         old time/op  new time/op  delta
XGarbage-12  2.31ms ± 0%  2.32ms ± 1%  +0.28%  (p=0.001 n=17+16)
XJSON-12     12.4ms ± 0%  12.4ms ± 0%  +0.41%  (p=0.000 n=18+18)
XHTTP-12     11.8µs ± 0%  11.8µs ± 1%    ~     (p=0.492 n=20+18)

It reduces the tail latency of the x/benchmarks HTTP benchmark:

name      old p50-time  new p50-time  delta
XHTTP-12    489µs ± 0%    491µs ± 1%  +0.54%  (p=0.000 n=20+18)

name      old p95-time  new p95-time  delta
XHTTP-12    957µs ± 1%    960µs ± 1%  +0.28%  (p=0.002 n=20+17)

name      old p99-time  new p99-time  delta
XHTTP-12   1.76ms ± 1%   1.64ms ± 1%  -7.20%  (p=0.000 n=20+18)

Comparing to the beginning of the hybrid barrier implementation
("runtime: parallelize STW mcache flushing") shows that the hybrid
barrier trades a small performance impact for much better STW latency,
as expected. The magnitude of the performance impact is generally
small:

name                      old time/op    new time/op    delta
BinaryTree17-12              2.37s ± 1%     2.42s ± 1%  +2.04%  (p=0.000 n=19+18)
Fannkuch11-12                2.84s ± 0%     2.72s ± 0%  -4.00%  (p=0.000 n=19+19)
FmtFprintfEmpty-12          44.2ns ± 1%    45.2ns ± 1%  +2.20%  (p=0.000 n=17+19)
FmtFprintfString-12          130ns ± 1%     134ns ± 0%  +2.94%  (p=0.000 n=18+16)
FmtFprintfInt-12             114ns ± 1%     117ns ± 0%  +3.01%  (p=0.000 n=19+15)
FmtFprintfIntInt-12          176ns ± 1%     182ns ± 0%  +3.17%  (p=0.000 n=20+15)
FmtFprintfPrefixedInt-12     186ns ± 1%     187ns ± 1%  +1.04%  (p=0.000 n=20+19)
FmtFprintfFloat-12           251ns ± 1%     250ns ± 1%  -0.74%  (p=0.000 n=17+18)
FmtManyArgs-12               746ns ± 1%     761ns ± 0%  +2.08%  (p=0.000 n=19+20)
GobDecode-12                6.57ms ± 1%    6.65ms ± 1%  +1.11%  (p=0.000 n=19+20)
GobEncode-12                5.59ms ± 1%    5.65ms ± 0%  +1.08%  (p=0.000 n=17+17)
Gzip-12                      223ms ± 1%     223ms ± 1%  -0.31%  (p=0.006 n=20+20)
Gunzip-12                   38.0ms ± 0%    37.9ms ± 1%  -0.25%  (p=0.009 n=19+20)
HTTPClientServer-12         77.5µs ± 1%    78.9µs ± 2%  +1.89%  (p=0.000 n=20+20)
JSONEncode-12               14.7ms ± 1%    14.9ms ± 0%  +0.75%  (p=0.000 n=20+20)
JSONDecode-12               53.0ms ± 1%    55.9ms ± 1%  +5.54%  (p=0.000 n=19+19)
Mandelbrot200-12            3.81ms ± 0%    3.81ms ± 1%  +0.20%  (p=0.023 n=17+19)
GoParse-12                  3.17ms ± 1%    3.18ms ± 1%    ~     (p=0.057 n=20+19)
RegexpMatchEasy0_32-12      71.7ns ± 1%    70.4ns ± 1%  -1.77%  (p=0.000 n=19+20)
RegexpMatchEasy0_1K-12       946ns ± 0%     946ns ± 0%    ~     (p=0.405 n=18+18)
RegexpMatchEasy1_32-12      67.2ns ± 2%    67.3ns ± 2%    ~     (p=0.732 n=20+20)
RegexpMatchEasy1_1K-12       374ns ± 1%     378ns ± 1%  +1.14%  (p=0.000 n=18+19)
RegexpMatchMedium_32-12      107ns ± 1%     107ns ± 1%    ~     (p=0.259 n=18+20)
RegexpMatchMedium_1K-12     34.2µs ± 1%    34.5µs ± 1%  +1.03%  (p=0.000 n=18+18)
RegexpMatchHard_32-12       1.77µs ± 1%    1.79µs ± 1%  +0.73%  (p=0.000 n=19+18)
RegexpMatchHard_1K-12       53.6µs ± 1%    54.2µs ± 1%  +1.10%  (p=0.000 n=19+19)
Template-12                 61.5ms ± 1%    63.9ms ± 0%  +3.96%  (p=0.000 n=18+18)
TimeParse-12                 303ns ± 1%     300ns ± 1%  -1.08%  (p=0.000 n=19+20)
TimeFormat-12                318ns ± 1%     320ns ± 0%  +0.79%  (p=0.000 n=19+19)
Revcomp-12 (*)               509ms ± 3%     504ms ± 0%    ~     (p=0.967 n=7+12)
[Geo mean]                  54.3µs         54.8µs       +0.88%

(*) Revcomp is highly non-linear, so I only took samples with 2
iterations.

name         old time/op  new time/op  delta
XGarbage-12  2.25ms ± 0%  2.32ms ± 1%  +2.74%  (p=0.000 n=16+16)
XJSON-12     11.6ms ± 0%  12.4ms ± 0%  +6.81%  (p=0.000 n=18+18)
XHTTP-12     11.6µs ± 1%  11.8µs ± 1%  +1.62%  (p=0.000 n=17+18)

Updates #17503.

Updates #17099, since you can't have a rescan list bug if there's no
rescan list. I'm not marking it as fixed, since gcrescanstacks can
still be set to re-enable the rescan lists.

Change-Id: I6e926b4c2dbd4cd56721869d4f817bdbb330b851
Reviewed-on: https://go-review.googlesource.com/31766Reviewed-by: 's avatarRick Hudson <rlh@golang.org>
      bd640c88
    • Austin Clements's avatar
      runtime: implement unconditional hybrid barrier · 5380b229
      Austin Clements authored 
      This implements the unconditional version of the hybrid deletion write
barrier, which always shades both the old and new pointer. It's
unconditional for now because barriers on channel operations require
checking both the source and destination stacks and we don't have a
way to funnel this information into the write barrier at the moment.

As part of this change, we modify the typed memclr operations
introduced earlier to invoke the write barrier.

This has basically no overall effect on benchmark performance. This is
good, since it indicates that neither the extra shade nor the new bulk
clear barriers have much effect. It also has little effect on latency.
This is expected, since we haven't yet modified mark termination to
take advantage of the hybrid barrier.

Updates #17503.

Change-Id: Iebedf84af2f0e857bd5d3a2d525f760b5cf7224b
Reviewed-on: https://go-review.googlesource.com/31765Reviewed-by: 's avatarRick Hudson <rlh@golang.org>
      5380b229
    • Austin Clements's avatar
      runtime: avoid getfull() barrier most of the time · ee3d2012
      Austin Clements authored 
      With the hybrid barrier, unless we're doing a STW GC or hit a very
rare race (~once per all.bash) that can start mark termination before
all of the work is drained, we don't need to drain the work queue at
all. Even draining an empty work queue is rather expensive since we
have to enter the getfull() barrier, so it's worth avoiding this.

Conveniently, it's quite easy to detect whether or not we actually
need the getufull() barrier: since the world is stopped when we enter
mark termination, everything must have flushed its work to the work
queue, so we can just check the queue. If the queue is empty and we
haven't queued up any jobs that may create more work (which should
always be the case with the hybrid barrier), we can simply have all GC
workers perform non-blocking drains.

Also conveniently, this solution is quite safe. If we do somehow screw
something up and there's work on the work queue, some worker will
still process it, it just may not happen in parallel.

This is not the "right" solution, but it's simple, expedient,
low-risk, and maintains compatibility with debug.gcrescanstacks. When
we remove the gcrescanstacks fallback in Go 1.9, we should also fix
the race that starts mark termination early, and then we can eliminate
work draining from mark termination.

Updates #17503.

Change-Id: I7b3cd5de6a248ab29d78c2b42aed8b7443641361
Reviewed-on: https://go-review.googlesource.com/32186Reviewed-by: 's avatarRick Hudson <rlh@golang.org>
      ee3d2012
    • Austin Clements's avatar
      runtime: remove unnecessary step from bulkBarrierPreWrite · d8256824
      Austin Clements authored 
      Currently bulkBarrierPreWrite calls writebarrierptr_prewrite, but this
means that we check writeBarrier.needed twice and perform cgo checks
twice.

Change bulkBarrierPreWrite to call writebarrierptr_prewrite1 to skip
over these duplicate checks.

This may speed up bulkBarrierPreWrite slightly, but mostly this will
save us from running out of nosplit stack space on ppc64x in the near
future.

Updates #17503.

Change-Id: I1cea1a2207e884ab1a279c6a5e378dcdc048b63e
Reviewed-on: https://go-review.googlesource.com/31890Reviewed-by: 's avatarRick Hudson <rlh@golang.org>
      d8256824
    • Austin Clements's avatar
      runtime: add deletion barriers on gobuf.ctxt · 70c107c6
      Austin Clements authored 
      gobuf.ctxt is set to nil from many places in assembly code and these
assignments require write barriers with the hybrid barrier.

Conveniently, in most of these places ctxt should already be nil, in
which case we don't need the barrier. This commit changes these places
to assert that ctxt is already nil.

gogo is more complicated, since ctxt may not already be nil. For gogo,
we manually perform the write barrier if ctxt is not nil.

Updates #17503.

Change-Id: I9d75e27c75a1b7f8b715ad112fc5d45ffa856d30
Reviewed-on: https://go-review.googlesource.com/31764Reviewed-by: 's avatarCherry Zhang <cherryyz@google.com>
      70c107c6
    • Austin Clements's avatar
      runtime: perform write barrier before pointer write · 8f81dfe8
      Austin Clements authored 
      Currently, we perform write barriers after performing pointer writes.
At the moment, it simply doesn't matter what order this happens in, as
long as they appear atomic to GC. But both the hybrid barrier and ROC
are going to require a pre-write write barrier.

For the hybrid barrier, this is important because the barrier needs to
observe both the current value of the slot and the value that will be
written to it. (Alternatively, the caller could do the write and pass
in the old value, but it seems easier and more useful to just swap the
order of the barrier and the write.)

For ROC, this is necessary because, if the pointer write is going to
make the pointer reachable to some goroutine that it currently is not
visible to, the garbage collector must take some special action before
that pointer becomes more broadly visible.

This commits swaps pointer writes around so the write barrier occurs
before the pointer write.

The main subtlety here is bulk memory writes. Currently, these copy to
the destination first and then use the pointer bitmap of the
destination to find the copied pointers and invoke the write barrier.
This is necessary because the source may not have a pointer bitmap. To
handle these, we pass both the source and the destination to the bulk
memory barrier, which uses the pointer bitmap of the destination, but
reads the pointer values from the source.

Updates #17503.

Change-Id: I78ecc0c5c94ee81c29019c305b3d232069294a55
Reviewed-on: https://go-review.googlesource.com/31763Reviewed-by: 's avatarRick Hudson <rlh@golang.org>
      8f81dfe8
    • Russ Cox's avatar
      cmd/go: apply import restrictions to test code too · 0f06d0a0
      Russ Cox authored 
      We reject import of main packages, but we missed tests.
Reject in all tests except test of that main package.

We reject local (relative) imports from code with a
non-local import path, but again we missed tests.
Reject those too.

Fixes #14811.
Fixes #15795.
Fixes #17475.

Change-Id: I535ff26889520276a891904f54f1a85b2c40207d
Reviewed-on: https://go-review.googlesource.com/31821
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarIan Lance Taylor <iant@golang.org>
Reviewed-by: 's avatarQuentin Smith <quentin@golang.org>
      0f06d0a0
    • Josh Bleecher Snyder's avatar
      cmd/compile: add Param to Sizeof test · 91c1cdfb
      Josh Bleecher Snyder authored 
      Change-Id: I2a710f0e9b484b3dfc581d3a9a23aa13321ec267
Reviewed-on: https://go-review.googlesource.com/32316
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: 's avatarBrad Fitzpatrick <bradfitz@golang.org>
      91c1cdfb
    • Cherry Zhang's avatar
      cmd/internal/obj/arm64: materialize float constant 0 from zero register · a866df26
      Cherry Zhang authored 
      Materialize float constant 0 from integer zero register, instead
of loading from constant pool.

Also fix assembling FMOV from zero register to FP register.

Change-Id: Ie413dd342cedebdb95ba8cfc220e23ed2a39e885
Reviewed-on: https://go-review.googlesource.com/32250
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarDavid Chase <drchase@google.com>
      a866df26
    • Cherry Zhang's avatar
      cmd/link: put text at address 0x1000000 on darwin/amd64 · 9d1efba2
      Cherry Zhang authored 
      Apparently on macOS Sierra LLDB thinks /usr/lib/dyld is mapped
at address 0, even if Go code starts at 0x1000, and it looks up
addresses from dyld which shadows Go symbols. Move Go binary at
a higher address to avoid clash.

Fixes #17463. Re-enable TestLldbPython.

Change-Id: I89ca6f3ee48aa6da9862bfa0c2da91477cc93255
Reviewed-on: https://go-review.googlesource.com/32185
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarQuentin Smith <quentin@golang.org>
      9d1efba2
    • Austin Clements's avatar
      cmd/compile: disable various write barrier optimizations · c39918a0
      Austin Clements authored 
      Several of our current write barrier elision optimizations are invalid
with the hybrid barrier. Eliding the hybrid barrier requires that
*both* the current and new pointer be already shaded and, since we
don't have the flow analysis to figure out anything about the slot's
current value, for now we have to just disable several of these
optimizations.

This has a slight impact on binary size. On linux/amd64, the go tool
binary increases by 0.7% and the compile binary increases by 1.5%.

It also has a slight impact on performance, as one would expect. We'll
win some of this back in subsequent commits.

name                      old time/op    new time/op    delta
BinaryTree17-12              2.38s ± 1%     2.40s ± 1%  +0.82%  (p=0.000 n=18+20)
Fannkuch11-12                2.84s ± 1%     2.70s ± 0%  -4.97%  (p=0.000 n=18+18)
FmtFprintfEmpty-12          44.2ns ± 1%    46.4ns ± 2%  +4.89%  (p=0.000 n=16+18)
FmtFprintfString-12          131ns ± 0%     134ns ± 1%  +2.05%  (p=0.000 n=12+19)
FmtFprintfInt-12             114ns ± 1%     117ns ± 1%  +3.26%  (p=0.000 n=19+20)
FmtFprintfIntInt-12          176ns ± 1%     181ns ± 1%  +3.25%  (p=0.000 n=20+20)
FmtFprintfPrefixedInt-12     185ns ± 1%     190ns ± 1%  +2.77%  (p=0.000 n=19+18)
FmtFprintfFloat-12           249ns ± 1%     254ns ± 1%  +1.71%  (p=0.000 n=18+20)
FmtManyArgs-12               747ns ± 1%     743ns ± 1%  -0.58%  (p=0.000 n=19+18)
GobDecode-12                6.57ms ± 1%    6.61ms ± 0%  +0.73%  (p=0.000 n=19+20)
GobEncode-12                5.58ms ± 1%    5.60ms ± 0%  +0.27%  (p=0.001 n=18+18)
Gzip-12                      223ms ± 1%     223ms ± 1%    ~     (p=0.351 n=19+20)
Gunzip-12                   37.9ms ± 0%    37.9ms ± 1%    ~     (p=0.095 n=16+20)
HTTPClientServer-12         77.8µs ± 1%    78.5µs ± 1%  +0.97%  (p=0.000 n=19+20)
JSONEncode-12               14.8ms ± 1%    14.8ms ± 1%    ~     (p=0.079 n=20+19)
JSONDecode-12               53.7ms ± 1%    54.2ms ± 1%  +0.92%  (p=0.000 n=20+19)
Mandelbrot200-12            3.81ms ± 1%    3.81ms ± 0%    ~     (p=0.916 n=19+18)
GoParse-12                  3.19ms ± 1%    3.19ms ± 1%    ~     (p=0.175 n=20+19)
RegexpMatchEasy0_32-12      71.9ns ± 1%    70.6ns ± 1%  -1.87%  (p=0.000 n=19+20)
RegexpMatchEasy0_1K-12       946ns ± 0%     944ns ± 0%  -0.22%  (p=0.000 n=19+16)
RegexpMatchEasy1_32-12      67.3ns ± 2%    66.8ns ± 1%  -0.72%  (p=0.008 n=20+20)
RegexpMatchEasy1_1K-12       374ns ± 1%     384ns ± 1%  +2.69%  (p=0.000 n=18+20)
RegexpMatchMedium_32-12      107ns ± 1%     107ns ± 1%    ~     (p=1.000 n=20+20)
RegexpMatchMedium_1K-12     34.3µs ± 1%    34.6µs ± 1%  +0.90%  (p=0.000 n=20+20)
RegexpMatchHard_32-12       1.78µs ± 1%    1.80µs ± 1%  +1.45%  (p=0.000 n=20+19)
RegexpMatchHard_1K-12       53.6µs ± 0%    54.5µs ± 1%  +1.52%  (p=0.000 n=19+18)
Revcomp-12                   417ms ± 5%     391ms ± 1%  -6.42%  (p=0.000 n=16+19)
Template-12                 61.1ms ± 1%    64.2ms ± 0%  +5.07%  (p=0.000 n=19+20)
TimeParse-12                 302ns ± 1%     305ns ± 1%  +0.90%  (p=0.000 n=18+18)
TimeFormat-12                319ns ± 1%     315ns ± 1%  -1.25%  (p=0.000 n=18+18)
[Geo mean]                  54.0µs         54.3µs       +0.58%

name         old time/op  new time/op  delta
XGarbage-12  2.24ms ± 2%  2.28ms ± 1%  +1.68%  (p=0.000 n=18+17)
XHTTP-12     11.4µs ± 1%  11.6µs ± 2%  +1.63%  (p=0.000 n=18+18)
XJSON-12     11.6ms ± 0%  12.5ms ± 0%  +7.84%  (p=0.000 n=18+17)

Updates #17503.

Change-Id: I1899f8e35662971e24bf692b517dfbe2b533c00c
Reviewed-on: https://go-review.googlesource.com/31572Reviewed-by: 's avatarKeith Randall <khr@golang.org>
      c39918a0
    • Austin Clements's avatar
      runtime: eliminate write barriers from save · c3163d23
      Austin Clements authored 
      As for dropg, save is writing a nil pointer that will generate a write
barrier with the hybrid barrier. However, in this case, ctxt always
should already be nil, so replace the write with an assertion that
this is the case.

At this point, we're ready to disable the write barrier elision
optimizations that interfere with the hybrid barrier.

Updates #17503.

Change-Id: I83208e65aa33403d442401f355b2e013ab9a50e9
Reviewed-on: https://go-review.googlesource.com/31571Reviewed-by: 's avatarRick Hudson <rlh@golang.org>
      c3163d23
    • Austin Clements's avatar
      runtime: eliminate write barriers from dropg · 8044b77a
      Austin Clements authored 
      Currently this contains no write barriers because it's writing nil
pointers, but with the hybrid barrier, even these will produce write
barriers. However, since these are *gs and *ms, they don't need write
barriers, so we can simply eliminate them.

Updates #17503.

Change-Id: Ib188a60492c5cfb352814bf9b2bcb2941fb7d6c0
Reviewed-on: https://go-review.googlesource.com/31570Reviewed-by: 's avatarRick Hudson <rlh@golang.org>
      8044b77a
    • Austin Clements's avatar
      runtime: mark tiny blocks at GC start · 85c22bc3
      Austin Clements authored 
      The hybrid barrier requires allocate-black, but there's one case where
we don't currently allocate black: the tiny allocator. If we allocate
a *new* tiny alloc block during GC, it will be allocated black, but if
we allocated the current block before GC, it won't be black, and the
further allocations from it won't mark it, which means we may free a
reachable tiny block during sweeping.

Fix this by passing over all mcaches at the beginning of mark, while
the world is still stopped, and greying their tiny blocks.

Updates #17503.

Change-Id: I04d4df7cc2f553f8f7b1e4cb0b52e2946588111a
Reviewed-on: https://go-review.googlesource.com/31456Reviewed-by: 's avatarRick Hudson <rlh@golang.org>
      85c22bc3
    • Austin Clements's avatar
      runtime: shade stack-to-stack copy when starting a goroutine · ee785f03
      Austin Clements authored 
      The hybrid barrier requires barriers on stack-to-stack copies if
either stack is grey. There are only two instances of this in the
runtime: channel sends and starting a goroutine. Channel sends already
use typedmemmove and hence have the necessary barriers. This commits
adds barriers for the stack-to-stack copy when starting a goroutine.

Updates #17503.

Change-Id: Ibb55e08127ca4d021ac54be61cb96732efa5df5b
Reviewed-on: https://go-review.googlesource.com/31455Reviewed-by: 's avatarRick Hudson <rlh@golang.org>
      ee785f03
    • Michael Matloob's avatar
      runtime/pprof/internal/profile: add copyright notice to profile_memmap.go · 0c0960a2
      Michael Matloob authored 
      Change-Id: Ia511b0aadc87eb53e084d14cdb90ba4be958a43e
Reviewed-on: https://go-review.googlesource.com/32259Reviewed-by: 's avatarAustin Clements <austin@google.com>
      0c0960a2
    • Michael Matloob's avatar
      runtime/pprof: write profiles in protobuf format. · b33030a7
      Michael Matloob authored 
      Original Change by Daria Kolistratova <daria.kolistratova@intel.com>

Added functions with suffix proto and stuff from pprof tool to translate
to protobuf. Done as the profile proto is more extensible than the legacy
pprof format and is pprof's preferred profile format. Large part was taken
from https://github.com/google/pprof tool. Tested by hand and compared the
result with translated by pprof tool, profiles are identical.
Fixes #16093

Change-Id: I2751345b09a66ee2b6aa64be76cba4cd1c326aa6
Reviewed-on: https://go-review.googlesource.com/32257
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: 's avatarAlan Donovan <adonovan@google.com>
      b33030a7
    • Russ Cox's avatar
      encoding/csv: document Read error behavior · 30651b3b
      Russ Cox authored 
      Fixes #17342.

Change-Id: I76af756d7aff464554c5564d444962a468d0eccc
Reviewed-on: https://go-review.googlesource.com/32172
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: 's avatarQuentin Smith <quentin@golang.org>
      30651b3b
    • Russ Cox's avatar
      cmd/go, go/build: document form of import paths · e2bcae78
      Russ Cox authored 
      Fixes #16164.

Change-Id: Ic8f51ebd8235640143913a07b70f5b41ee061fe4
Reviewed-on: https://go-review.googlesource.com/32114Reviewed-by: 's avatarQuentin Smith <quentin@golang.org>
      e2bcae78