A temporary 512 bytes buffer is allocated for every call to
readHeader. This buffer isn't returned to the caller and it could
be reused to lower the number of memory allocations.
This CL improves it by using a pool and zeroing out the buffer before
putting it back into the pool.
benchmark old ns/op new ns/op delta
BenchmarkListFiles100k 545249903 538832687 -1.18%
benchmark old allocs new allocs delta
BenchmarkListFiles100k 2105167 2005692 -4.73%
benchmark old bytes new bytes delta
BenchmarkListFiles100k 105903472 54831527 -48.22%
This improvement is very important if your code has to deal with a lot
of tarballs which contain a lot of files.
LGTM=dsymonds
R=golang-codereviews, dave, dsymonds, bradfitz
CC=golang-codereviews
https://golang.org/cl/108240044
A temporary 512 bytes buffer is allocated for every call to
writeHeader. This buffer could be reused the lower the number
of memory allocations.
benchmark old ns/op new ns/op delta
BenchmarkWriteFiles100k 634622051 583810847 -8.01%
benchmark old allocs new allocs delta
BenchmarkWriteFiles100k 2701920 2602621 -3.68%
benchmark old bytes new bytes delta
BenchmarkWriteFiles100k 115383884 64349922 -44.23%
This change is very important if your code has to write a lot of
tarballs with a lot of files.
LGTM=dsymonds
R=golang-codereviews, dave, dsymonds
CC=golang-codereviews
https://golang.org/cl/107440043
Thanks to Cedric Staub for noting that a short session key would lead
to an out-of-bounds access when conditionally copying the too short
buffer over the random session key.
LGTM=davidben, bradfitz
R=davidben, bradfitz
CC=golang-codereviews
https://golang.org/cl/102670044
The main changes fall into a few patterns:
1. Replace #define with enum.
2. Add /*c2go */ comment giving effect of #define.
This is necessary for function-like #defines and
non-enum-able #defined constants.
(Not all compilers handle negative or large enums.)
3. Add extra braces in struct initializer.
(c2go does not implement the full rules.)
This is enough to let c2go typecheck the source tree.
There may be more changes once it is doing
other semantic analyses.
LGTM=minux, iant
R=minux, dave, iant
CC=golang-codereviews
https://golang.org/cl/106860045
A TLS slot is reserved by _rt0_.*_plan9 as an automatic and
its address (which is static on Plan 9) is saved in the
global _privates symbol. The startup linkage now is exactly
like that from Plan 9 libc, and the way we access g is
exactly as if we'd have used privalloc(2).
Aside from making the code more standard, this change
drastically simplifies it, both for 386 and for amd64, and
makes the Plan 9 code in liblink common for both 386 and
amd64.
The amd64 runtime code was cleared of nxm assumptions, and
now runs on the standard Plan 9 kernel.
Note handling fixes will follow in a separate CL.
LGTM=rsc
R=golang-codereviews, rsc, bradfitz, dave
CC=0intro, ality, golang-codereviews, jas, minux.ma, mischief
https://golang.org/cl/101510049
We restored registers correctly in the usual case where the thread
is a Go-managed thread and called runtime·sighandler, but we
failed to do so when runtime·sigtramp was called on a cgo-created
thread. In that case, runtime·sigtramp called runtime·badsignal,
a Go function, and did not restore registers after it returned
LGTM=rsc, dave
R=rsc, dave
CC=golang-codereviews, minux.ma
https://golang.org/cl/105280050
On amd64, the real time is reduced from 176.76s to 140.26s.
On ARM, the real time is reduced from 921.61s to 726.30s.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/101580043
Move decAlloc calls a bit higher in the call tree.
Cleans code marginally, improves speed marginally.
The benchmarks are noisy but the median time from
20 consective 1-second runs improves by about 2%.
LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/105530043
3-index slices of the form s[:len(s):len(s)]
cannot be simplified to s[::len(s)].
LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/108330043
We are not the right people to support editor plugins, and the profusion
of editors in this CL demonstrates the unreality of pretending to do so.
People are free to create and advertise their own repos with support.
For discussion: https://groups.google.com/forum/#!topic/golang-dev/SA7fD470FxU
LGTM=rminnich, kamil.kisiel, gri, rsc, dave, josharian, ruiu
R=golang-codereviews, rminnich, kamil.kisiel, gri, rsc, dominik.honnef, dave, josharian, ruiu, ajstarks
CC=golang-codereviews
https://golang.org/cl/105470043
There is no reason to generate different code for cap and len.
Fixes#8025.
Fixes#8026.
LGTM=rsc
R=rsc, iant, khr
CC=golang-codereviews
https://golang.org/cl/93570044
Breaks windows and race detector.
TBR=rsc
««« original CL description
runtime: stack allocator, separate from mallocgc
In order to move malloc to Go, we need to have a
separate stack allocator. If we run out of stack
during malloc, malloc will not be available
to allocate a new stack.
Stacks are the last remaining FlagNoGC objects in the
GC heap. Once they are out, we can get rid of the
distinction between the allocated/blockboundary bits.
(This will be in a separate change.)
Fixes#7468Fixes#7424
LGTM=rsc, dvyukov
R=golang-codereviews, dvyukov, khr, dave, rsc
CC=golang-codereviews
https://golang.org/cl/104200047
»»»
TBR=rsc
CC=golang-codereviews
https://golang.org/cl/101570044
In order to move malloc to Go, we need to have a
separate stack allocator. If we run out of stack
during malloc, malloc will not be available
to allocate a new stack.
Stacks are the last remaining FlagNoGC objects in the
GC heap. Once they are out, we can get rid of the
distinction between the allocated/blockboundary bits.
(This will be in a separate change.)
Fixes#7468Fixes#7424
LGTM=rsc, dvyukov
R=golang-codereviews, dvyukov, khr, dave, rsc
CC=golang-codereviews
https://golang.org/cl/104200047
The old code's structure needed to track indirections because of the
use of unsafe. That is no longer necessary, so we can remove all
that tracking. The code cleans up considerably but is a little slower.
We may be able to recover that performance drop. I believe the
code quality improvement is worthwhile regardless.
BenchmarkEndToEndPipe 5610 5780 +3.03%
BenchmarkEndToEndByteBuffer 3156 3222 +2.09%
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/103700043
If the actual types of two reflect values are
the same and the values are structs, they must
have the same number of fields.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/108280043
This removes a major unsafe thorn in our side, a perennial obstacle
to clean garbage collection.
Not coincidentally: In cleaning this up, several bugs were found,
including code that reached inside by-value interfaces to create
pointers for pointer-receiver methods. Unsafe code is just as
advertised.
Performance of course suffers, but not too badly. The Pipe number
is more indicative, since it's doing I/O that simulates a network
connection. Plus these are end-to-end, so each end suffers
only half of this pain.
The edit is pretty much a line-by-line conversion, with a few
simplifications and a couple of new tests. There may be more
performance to gain.
BenchmarkEndToEndByteBuffer 2493 3033 +21.66%
BenchmarkEndToEndPipe 4953 5597 +13.00%
Fixes#5159.
LGTM=rsc
R=rsc
CC=golang-codereviews, khr
https://golang.org/cl/102680045
The only text that describes the accepted format is in the package doc,
which is far away from these functions. The other flag types don't need
this explicitness because they are more obvious.
LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/101550043
Remove GC bitmap backward scanning.
This was already done once in https://golang.org/cl/5530074/
Still makes GC a bit faster.
On the garbage benchmark, before:
gc-pause-one=237345195
gc-pause-total=4746903
cputime=32427775
time=32458208
after:
gc-pause-one=235484019
gc-pause-total=4709680
cputime=31861965
time=31877772
Also prepares mgc0.c for future changes.
R=golang-codereviews, khr, khr
CC=golang-codereviews, rsc
https://golang.org/cl/105380043
newproc takes two extra pointers, not two extra registers.
On amd64p32 (nacl) they are different.
We diagnosed this before the 1.3 cut but the tree was frozen.
I believe this is causing the random problems on the builder.
Fixes#8199.
TBR=r
CC=golang-codereviews
https://golang.org/cl/102710043
Include these files in the build,
even though they don't get executed.
LGTM=r
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/108180043
Output number of spinning threads,
this is useful to understanding whether the scheduler
is in a steady state or not.
R=golang-codereviews, khr
CC=golang-codereviews, rsc
https://golang.org/cl/103540045
Say when a goroutine is locked to OS thread in crash reports
and goroutine profiles.
It can be useful to understand what goroutines consume OS threads
(syscall and locked), e.g. if you forget to call UnlockOSThread
or leak locked goroutines.
R=golang-codereviews
CC=golang-codereviews, rsc
https://golang.org/cl/94170043
Pending acceptance of CL 101500044
and adjustment of test/fixedbugs/bug299.go.
LGTM=adonovan
R=golang-codereviews, adonovan
CC=golang-codereviews
https://golang.org/cl/110160043
The runtime has historically held two dedicated values g (current goroutine)
and m (current thread) in 'extern register' slots (TLS on x86, real registers
backed by TLS on ARM).
This CL removes the extern register m; code now uses g->m.
On ARM, this frees up the register that formerly held m (R9).
This is important for NaCl, because NaCl ARM code cannot use R9 at all.
The Go 1 macrobenchmarks (those with per-op times >= 10 µs) are unaffected:
BenchmarkBinaryTree17 5491374955 5471024381 -0.37%
BenchmarkFannkuch11 4357101311 4275174828 -1.88%
BenchmarkGobDecode 11029957 11364184 +3.03%
BenchmarkGobEncode 6852205 6784822 -0.98%
BenchmarkGzip 650795967 650152275 -0.10%
BenchmarkGunzip 140962363 141041670 +0.06%
BenchmarkHTTPClientServer 71581 73081 +2.10%
BenchmarkJSONEncode 31928079 31913356 -0.05%
BenchmarkJSONDecode 117470065 113689916 -3.22%
BenchmarkMandelbrot200 6008923 5998712 -0.17%
BenchmarkGoParse 6310917 6327487 +0.26%
BenchmarkRegexpMatchMedium_1K 114568 114763 +0.17%
BenchmarkRegexpMatchHard_1K 168977 169244 +0.16%
BenchmarkRevcomp 935294971 914060918 -2.27%
BenchmarkTemplate 145917123 148186096 +1.55%
Minux previous reported larger variations, but these were caused by
run-to-run noise, not repeatable slowdowns.
Actual code changes by Minux.
I only did the docs and the benchmarking.
LGTM=dvyukov, iant, minux
R=minux, josharian, iant, dave, bradfitz, dvyukov
CC=golang-codereviews
https://golang.org/cl/109050043
A single iteration of BenchmarkSaveRestore runs for 5 seconds
on my freebsd machine. 5 seconds looks like too long for a single
iteration.
This is the only benchmark that times out on freebsd-amd64-race builder.
R=golang-codereviews, dave
CC=golang-codereviews
https://golang.org/cl/107340044
Breaks the build
««« original CL description
cmd/go: build test files containing non-runnable examples
Even if we can't run them, we should at least check that they compile.
LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/107320046
»»»
TBR=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/110140044
Runs for 4 seconds on my mac.
Also this is the only test that times out on freebsd in -race mode.
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/110150045
