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go/src/runtime/sizeclasses.go

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runtime, unicode: use consistent banner for generated code Per golang.org/s/generatedcode Updates #nnn Change-Id: Ia7513ef6bd26c20b62b57b29f7770684a315d389 Reviewed-on: https://go-review.googlesource.com/45470 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Matt Layher <mdlayher@gmail.com> Reviewed-by: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-06-10 20:08:18 -07:00
// Code generated by mksizeclasses.go; DO NOT EDIT.
runtime: compute size classes statically No point in computing this info on startup. Compute it at build time. This lets us spend more time computing & checking the size classes. Improve the div magic for rounding to the start of an object. We can now use 32-bit multiplies & shifts, which should help 32-bit platforms. The static data is <1KB. The actual size classes are not changed by this CL. Change-Id: I6450cec7d1b2b4ad31fd3f945f504ed2ec6570e7 Reviewed-on: https://go-review.googlesource.com/32219 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2016-10-26 21:25:56 -07:00
//go:generate go run mksizeclasses.go
package runtime
runtime: add "max waste" column to size class table comment This computes the maximum possible waste in a size class due to both internal and external fragmentation as a percent of the span size. This parallels the reasoning about overhead in the comment at the top of mksizeclasses.go and confirms that comment's assertion that (except for the few smallest size classes), none of the size classes have worst-case internal and external fragmentation simultaneously. Change-Id: Idb66fe6c241d56f33d391831d4cd5a626955562b Reviewed-on: https://go-review.googlesource.com/49370 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2017-07-17 16:30:21 -04:00
// class bytes/obj bytes/span objects tail waste max waste
// 1 8 8192 1024 0 87.50%
// 2 16 8192 512 0 43.75%
runtime: add 24 byte allocation size class This CL introduces a 24 byte allocation size class which fits 3 pointers on 64 bit and 6 pointers on 32 bit architectures. Notably this new size class fits a slice header on 64 bit architectures exactly while previously a 32 byte size class would have been used for allocating a slice header on the heap. The main complexity added with this CL is that heapBitsSetType needs to handle objects that aren't 16-byte aligned but contain more than a single pointer on 64-bit architectures. Due to having a non 16 byte aligned size class on 32 bit a h.shift of 2 is now possible which means a heap bitmap byte might only be partially written. Due to this already having been possible on 64 bit before the heap bitmap code only needed minor adjustments for 32 bit doublecheck code paths. Note that this CL changes the slice capacity allocated by append for slice growth to a target capacity of 17 to 24 bytes. On 64 bit architectures the capacity of the slice returned by append([]byte{}, make([]byte, 24)...)) is 32 bytes before and 24 bytes after this CL. Depending on allocation patterns of the specific Go program this can increase the number of total alloctions as subsequent appends to the slice can trigger slice growth earlier than before. On the other side if the slice is never appended to again above its capacity this will lower heap usage by 8 bytes. This CL changes the set of size classes reported in the runtime.MemStats.BySize array due to it being limited to a total of 61 size classes. The new 24 byte size class is now included and the 20480 byte size class is not included anymore. Fixes #8885 name old time/op new time/op delta Template 196ms ± 3% 194ms ± 2% ~ (p=0.247 n=10+10) Unicode 85.6ms ±16% 88.1ms ± 1% ~ (p=0.165 n=10+10) GoTypes 673ms ± 2% 668ms ± 2% ~ (p=0.258 n=9+9) Compiler 3.14s ± 6% 3.08s ± 1% ~ (p=0.243 n=10+9) SSA 6.82s ± 1% 6.76s ± 1% -0.87% (p=0.006 n=9+10) Flate 128ms ± 7% 127ms ± 3% ~ (p=0.739 n=10+10) GoParser 154ms ± 3% 153ms ± 4% ~ (p=0.730 n=9+9) Reflect 404ms ± 1% 412ms ± 4% +1.99% (p=0.022 n=9+10) Tar 172ms ± 4% 170ms ± 4% ~ (p=0.065 n=10+9) XML 231ms ± 4% 230ms ± 3% ~ (p=0.912 n=10+10) LinkCompiler 341ms ± 1% 339ms ± 1% ~ (p=0.243 n=9+10) ExternalLinkCompiler 1.72s ± 1% 1.72s ± 1% ~ (p=0.661 n=9+10) LinkWithoutDebugCompiler 221ms ± 2% 221ms ± 2% ~ (p=0.529 n=10+10) StdCmd 18.4s ± 3% 18.2s ± 1% ~ (p=0.515 n=10+8) name old user-time/op new user-time/op delta Template 238ms ± 4% 243ms ± 6% ~ (p=0.661 n=9+10) Unicode 116ms ± 6% 113ms ± 3% -3.37% (p=0.035 n=9+10) GoTypes 854ms ± 2% 848ms ± 2% ~ (p=0.604 n=9+10) Compiler 4.10s ± 1% 4.11s ± 1% ~ (p=0.481 n=8+9) SSA 9.49s ± 1% 9.41s ± 1% -0.92% (p=0.001 n=9+10) Flate 149ms ± 6% 151ms ± 7% ~ (p=0.481 n=10+10) GoParser 189ms ± 2% 190ms ± 2% ~ (p=0.497 n=9+10) Reflect 511ms ± 2% 508ms ± 2% ~ (p=0.211 n=9+10) Tar 215ms ± 4% 212ms ± 3% ~ (p=0.105 n=10+10) XML 288ms ± 2% 288ms ± 2% ~ (p=0.971 n=10+10) LinkCompiler 559ms ± 4% 557ms ± 1% ~ (p=0.968 n=9+10) ExternalLinkCompiler 1.78s ± 1% 1.77s ± 1% ~ (p=0.055 n=8+10) LinkWithoutDebugCompiler 245ms ± 3% 245ms ± 2% ~ (p=0.684 n=10+10) name old alloc/op new alloc/op delta Template 34.8MB ± 0% 34.4MB ± 0% -0.95% (p=0.000 n=9+10) Unicode 28.6MB ± 0% 28.3MB ± 0% -0.95% (p=0.000 n=10+10) GoTypes 115MB ± 0% 114MB ± 0% -1.02% (p=0.000 n=10+9) Compiler 554MB ± 0% 549MB ± 0% -0.86% (p=0.000 n=9+10) SSA 1.28GB ± 0% 1.27GB ± 0% -0.83% (p=0.000 n=10+10) Flate 21.8MB ± 0% 21.6MB ± 0% -0.87% (p=0.000 n=8+10) GoParser 26.7MB ± 0% 26.4MB ± 0% -0.97% (p=0.000 n=10+9) Reflect 75.0MB ± 0% 74.1MB ± 0% -1.18% (p=0.000 n=10+10) Tar 32.6MB ± 0% 32.3MB ± 0% -0.94% (p=0.000 n=10+7) XML 41.5MB ± 0% 41.2MB ± 0% -0.90% (p=0.000 n=10+8) LinkCompiler 105MB ± 0% 104MB ± 0% -0.94% (p=0.000 n=10+10) ExternalLinkCompiler 153MB ± 0% 152MB ± 0% -0.69% (p=0.000 n=10+10) LinkWithoutDebugCompiler 63.7MB ± 0% 63.6MB ± 0% -0.13% (p=0.000 n=10+10) name old allocs/op new allocs/op delta Template 336k ± 0% 336k ± 0% +0.02% (p=0.002 n=10+10) Unicode 332k ± 0% 332k ± 0% ~ (p=0.447 n=10+10) GoTypes 1.16M ± 0% 1.16M ± 0% +0.01% (p=0.001 n=10+10) Compiler 4.92M ± 0% 4.92M ± 0% +0.01% (p=0.000 n=10+10) SSA 11.9M ± 0% 11.9M ± 0% +0.02% (p=0.000 n=9+10) Flate 214k ± 0% 214k ± 0% +0.02% (p=0.032 n=10+8) GoParser 270k ± 0% 270k ± 0% +0.02% (p=0.004 n=10+9) Reflect 877k ± 0% 877k ± 0% +0.01% (p=0.000 n=10+10) Tar 313k ± 0% 313k ± 0% ~ (p=0.075 n=9+10) XML 387k ± 0% 387k ± 0% +0.02% (p=0.007 n=10+10) LinkCompiler 455k ± 0% 456k ± 0% +0.08% (p=0.000 n=10+9) ExternalLinkCompiler 670k ± 0% 671k ± 0% +0.06% (p=0.000 n=10+10) LinkWithoutDebugCompiler 113k ± 0% 113k ± 0% ~ (p=0.149 n=10+10) name old maxRSS/op new maxRSS/op delta Template 34.1M ± 1% 34.1M ± 1% ~ (p=0.853 n=10+10) Unicode 35.1M ± 1% 34.6M ± 1% -1.43% (p=0.000 n=10+10) GoTypes 72.8M ± 3% 73.3M ± 2% ~ (p=0.724 n=10+10) Compiler 288M ± 3% 295M ± 4% ~ (p=0.393 n=10+10) SSA 630M ± 1% 622M ± 1% -1.18% (p=0.001 n=10+10) Flate 26.0M ± 1% 26.2M ± 2% ~ (p=0.493 n=10+10) GoParser 28.6M ± 1% 28.5M ± 2% ~ (p=0.256 n=10+10) Reflect 55.5M ± 2% 55.4M ± 1% ~ (p=0.436 n=10+10) Tar 33.0M ± 1% 32.8M ± 2% ~ (p=0.075 n=10+10) XML 38.7M ± 1% 39.0M ± 1% ~ (p=0.053 n=9+10) LinkCompiler 164M ± 1% 164M ± 1% -0.27% (p=0.029 n=10+10) ExternalLinkCompiler 174M ± 0% 173M ± 0% -0.33% (p=0.002 n=9+10) LinkWithoutDebugCompiler 137M ± 0% 136M ± 2% ~ (p=0.825 n=9+10) Change-Id: I9ecf2a10024513abef8fbfbe519e44e0b29b6167 Reviewed-on: https://go-review.googlesource.com/c/go/+/242258 Trust: Martin Möhrmann <moehrmann@google.com> Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Martin Möhrmann <martisch@uos.de> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Keith Randall <khr@golang.org>
2020-07-13 18:12:20 +02:00
// 3 24 8192 341 8 29.24%
// 4 32 8192 256 0 21.88%
// 5 48 8192 170 32 31.52%
// 6 64 8192 128 0 23.44%
// 7 80 8192 102 32 19.07%
// 8 96 8192 85 32 15.95%
// 9 112 8192 73 16 13.56%
// 10 128 8192 64 0 11.72%
// 11 144 8192 56 128 11.82%
// 12 160 8192 51 32 9.73%
// 13 176 8192 46 96 9.59%
// 14 192 8192 42 128 9.25%
// 15 208 8192 39 80 8.12%
// 16 224 8192 36 128 8.15%
// 17 240 8192 34 32 6.62%
// 18 256 8192 32 0 5.86%
// 19 288 8192 28 128 12.16%
// 20 320 8192 25 192 11.80%
// 21 352 8192 23 96 9.88%
// 22 384 8192 21 128 9.51%
// 23 416 8192 19 288 10.71%
// 24 448 8192 18 128 8.37%
// 25 480 8192 17 32 6.82%
// 26 512 8192 16 0 6.05%
// 27 576 8192 14 128 12.33%
// 28 640 8192 12 512 15.48%
// 29 704 8192 11 448 13.93%
// 30 768 8192 10 512 13.94%
// 31 896 8192 9 128 15.52%
// 32 1024 8192 8 0 12.40%
// 33 1152 8192 7 128 12.41%
// 34 1280 8192 6 512 15.55%
// 35 1408 16384 11 896 14.00%
// 36 1536 8192 5 512 14.00%
// 37 1792 16384 9 256 15.57%
// 38 2048 8192 4 0 12.45%
// 39 2304 16384 7 256 12.46%
// 40 2688 8192 3 128 15.59%
// 41 3072 24576 8 0 12.47%
// 42 3200 16384 5 384 6.22%
// 43 3456 24576 7 384 8.83%
// 44 4096 8192 2 0 15.60%
// 45 4864 24576 5 256 16.65%
// 46 5376 16384 3 256 10.92%
// 47 6144 24576 4 0 12.48%
// 48 6528 32768 5 128 6.23%
// 49 6784 40960 6 256 4.36%
// 50 6912 49152 7 768 3.37%
// 51 8192 8192 1 0 15.61%
// 52 9472 57344 6 512 14.28%
// 53 9728 49152 5 512 3.64%
// 54 10240 40960 4 0 4.99%
// 55 10880 32768 3 128 6.24%
// 56 12288 24576 2 0 11.45%
// 57 13568 40960 3 256 9.99%
// 58 14336 57344 4 0 5.35%
// 59 16384 16384 1 0 12.49%
// 60 18432 73728 4 0 11.11%
// 61 19072 57344 3 128 3.57%
// 62 20480 40960 2 0 6.87%
// 63 21760 65536 3 256 6.25%
// 64 24576 24576 1 0 11.45%
// 65 27264 81920 3 128 10.00%
// 66 28672 57344 2 0 4.91%
// 67 32768 32768 1 0 12.50%
runtime: add table of size classes in a comment Change-Id: I52fae67c9aeceaa23e70f2ef0468745b354f8c75 Reviewed-on: https://go-review.googlesource.com/34932 Reviewed-by: Minux Ma <minux@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2016-12-24 17:03:10 -08:00
runtime: compute size classes statically No point in computing this info on startup. Compute it at build time. This lets us spend more time computing & checking the size classes. Improve the div magic for rounding to the start of an object. We can now use 32-bit multiplies & shifts, which should help 32-bit platforms. The static data is <1KB. The actual size classes are not changed by this CL. Change-Id: I6450cec7d1b2b4ad31fd3f945f504ed2ec6570e7 Reviewed-on: https://go-review.googlesource.com/32219 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2016-10-26 21:25:56 -07:00
const (
_MaxSmallSize = 32768
smallSizeDiv = 8
smallSizeMax = 1024
largeSizeDiv = 128
runtime: add 24 byte allocation size class This CL introduces a 24 byte allocation size class which fits 3 pointers on 64 bit and 6 pointers on 32 bit architectures. Notably this new size class fits a slice header on 64 bit architectures exactly while previously a 32 byte size class would have been used for allocating a slice header on the heap. The main complexity added with this CL is that heapBitsSetType needs to handle objects that aren't 16-byte aligned but contain more than a single pointer on 64-bit architectures. Due to having a non 16 byte aligned size class on 32 bit a h.shift of 2 is now possible which means a heap bitmap byte might only be partially written. Due to this already having been possible on 64 bit before the heap bitmap code only needed minor adjustments for 32 bit doublecheck code paths. Note that this CL changes the slice capacity allocated by append for slice growth to a target capacity of 17 to 24 bytes. On 64 bit architectures the capacity of the slice returned by append([]byte{}, make([]byte, 24)...)) is 32 bytes before and 24 bytes after this CL. Depending on allocation patterns of the specific Go program this can increase the number of total alloctions as subsequent appends to the slice can trigger slice growth earlier than before. On the other side if the slice is never appended to again above its capacity this will lower heap usage by 8 bytes. This CL changes the set of size classes reported in the runtime.MemStats.BySize array due to it being limited to a total of 61 size classes. The new 24 byte size class is now included and the 20480 byte size class is not included anymore. Fixes #8885 name old time/op new time/op delta Template 196ms ± 3% 194ms ± 2% ~ (p=0.247 n=10+10) Unicode 85.6ms ±16% 88.1ms ± 1% ~ (p=0.165 n=10+10) GoTypes 673ms ± 2% 668ms ± 2% ~ (p=0.258 n=9+9) Compiler 3.14s ± 6% 3.08s ± 1% ~ (p=0.243 n=10+9) SSA 6.82s ± 1% 6.76s ± 1% -0.87% (p=0.006 n=9+10) Flate 128ms ± 7% 127ms ± 3% ~ (p=0.739 n=10+10) GoParser 154ms ± 3% 153ms ± 4% ~ (p=0.730 n=9+9) Reflect 404ms ± 1% 412ms ± 4% +1.99% (p=0.022 n=9+10) Tar 172ms ± 4% 170ms ± 4% ~ (p=0.065 n=10+9) XML 231ms ± 4% 230ms ± 3% ~ (p=0.912 n=10+10) LinkCompiler 341ms ± 1% 339ms ± 1% ~ (p=0.243 n=9+10) ExternalLinkCompiler 1.72s ± 1% 1.72s ± 1% ~ (p=0.661 n=9+10) LinkWithoutDebugCompiler 221ms ± 2% 221ms ± 2% ~ (p=0.529 n=10+10) StdCmd 18.4s ± 3% 18.2s ± 1% ~ (p=0.515 n=10+8) name old user-time/op new user-time/op delta Template 238ms ± 4% 243ms ± 6% ~ (p=0.661 n=9+10) Unicode 116ms ± 6% 113ms ± 3% -3.37% (p=0.035 n=9+10) GoTypes 854ms ± 2% 848ms ± 2% ~ (p=0.604 n=9+10) Compiler 4.10s ± 1% 4.11s ± 1% ~ (p=0.481 n=8+9) SSA 9.49s ± 1% 9.41s ± 1% -0.92% (p=0.001 n=9+10) Flate 149ms ± 6% 151ms ± 7% ~ (p=0.481 n=10+10) GoParser 189ms ± 2% 190ms ± 2% ~ (p=0.497 n=9+10) Reflect 511ms ± 2% 508ms ± 2% ~ (p=0.211 n=9+10) Tar 215ms ± 4% 212ms ± 3% ~ (p=0.105 n=10+10) XML 288ms ± 2% 288ms ± 2% ~ (p=0.971 n=10+10) LinkCompiler 559ms ± 4% 557ms ± 1% ~ (p=0.968 n=9+10) ExternalLinkCompiler 1.78s ± 1% 1.77s ± 1% ~ (p=0.055 n=8+10) LinkWithoutDebugCompiler 245ms ± 3% 245ms ± 2% ~ (p=0.684 n=10+10) name old alloc/op new alloc/op delta Template 34.8MB ± 0% 34.4MB ± 0% -0.95% (p=0.000 n=9+10) Unicode 28.6MB ± 0% 28.3MB ± 0% -0.95% (p=0.000 n=10+10) GoTypes 115MB ± 0% 114MB ± 0% -1.02% (p=0.000 n=10+9) Compiler 554MB ± 0% 549MB ± 0% -0.86% (p=0.000 n=9+10) SSA 1.28GB ± 0% 1.27GB ± 0% -0.83% (p=0.000 n=10+10) Flate 21.8MB ± 0% 21.6MB ± 0% -0.87% (p=0.000 n=8+10) GoParser 26.7MB ± 0% 26.4MB ± 0% -0.97% (p=0.000 n=10+9) Reflect 75.0MB ± 0% 74.1MB ± 0% -1.18% (p=0.000 n=10+10) Tar 32.6MB ± 0% 32.3MB ± 0% -0.94% (p=0.000 n=10+7) XML 41.5MB ± 0% 41.2MB ± 0% -0.90% (p=0.000 n=10+8) LinkCompiler 105MB ± 0% 104MB ± 0% -0.94% (p=0.000 n=10+10) ExternalLinkCompiler 153MB ± 0% 152MB ± 0% -0.69% (p=0.000 n=10+10) LinkWithoutDebugCompiler 63.7MB ± 0% 63.6MB ± 0% -0.13% (p=0.000 n=10+10) name old allocs/op new allocs/op delta Template 336k ± 0% 336k ± 0% +0.02% (p=0.002 n=10+10) Unicode 332k ± 0% 332k ± 0% ~ (p=0.447 n=10+10) GoTypes 1.16M ± 0% 1.16M ± 0% +0.01% (p=0.001 n=10+10) Compiler 4.92M ± 0% 4.92M ± 0% +0.01% (p=0.000 n=10+10) SSA 11.9M ± 0% 11.9M ± 0% +0.02% (p=0.000 n=9+10) Flate 214k ± 0% 214k ± 0% +0.02% (p=0.032 n=10+8) GoParser 270k ± 0% 270k ± 0% +0.02% (p=0.004 n=10+9) Reflect 877k ± 0% 877k ± 0% +0.01% (p=0.000 n=10+10) Tar 313k ± 0% 313k ± 0% ~ (p=0.075 n=9+10) XML 387k ± 0% 387k ± 0% +0.02% (p=0.007 n=10+10) LinkCompiler 455k ± 0% 456k ± 0% +0.08% (p=0.000 n=10+9) ExternalLinkCompiler 670k ± 0% 671k ± 0% +0.06% (p=0.000 n=10+10) LinkWithoutDebugCompiler 113k ± 0% 113k ± 0% ~ (p=0.149 n=10+10) name old maxRSS/op new maxRSS/op delta Template 34.1M ± 1% 34.1M ± 1% ~ (p=0.853 n=10+10) Unicode 35.1M ± 1% 34.6M ± 1% -1.43% (p=0.000 n=10+10) GoTypes 72.8M ± 3% 73.3M ± 2% ~ (p=0.724 n=10+10) Compiler 288M ± 3% 295M ± 4% ~ (p=0.393 n=10+10) SSA 630M ± 1% 622M ± 1% -1.18% (p=0.001 n=10+10) Flate 26.0M ± 1% 26.2M ± 2% ~ (p=0.493 n=10+10) GoParser 28.6M ± 1% 28.5M ± 2% ~ (p=0.256 n=10+10) Reflect 55.5M ± 2% 55.4M ± 1% ~ (p=0.436 n=10+10) Tar 33.0M ± 1% 32.8M ± 2% ~ (p=0.075 n=10+10) XML 38.7M ± 1% 39.0M ± 1% ~ (p=0.053 n=9+10) LinkCompiler 164M ± 1% 164M ± 1% -0.27% (p=0.029 n=10+10) ExternalLinkCompiler 174M ± 0% 173M ± 0% -0.33% (p=0.002 n=9+10) LinkWithoutDebugCompiler 137M ± 0% 136M ± 2% ~ (p=0.825 n=9+10) Change-Id: I9ecf2a10024513abef8fbfbe519e44e0b29b6167 Reviewed-on: https://go-review.googlesource.com/c/go/+/242258 Trust: Martin Möhrmann <moehrmann@google.com> Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Martin Möhrmann <martisch@uos.de> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Keith Randall <khr@golang.org>
2020-07-13 18:12:20 +02:00
_NumSizeClasses = 68
runtime: compute size classes statically No point in computing this info on startup. Compute it at build time. This lets us spend more time computing & checking the size classes. Improve the div magic for rounding to the start of an object. We can now use 32-bit multiplies & shifts, which should help 32-bit platforms. The static data is <1KB. The actual size classes are not changed by this CL. Change-Id: I6450cec7d1b2b4ad31fd3f945f504ed2ec6570e7 Reviewed-on: https://go-review.googlesource.com/32219 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2016-10-26 21:25:56 -07:00
_PageShift = 13
)
runtime: add 24 byte allocation size class This CL introduces a 24 byte allocation size class which fits 3 pointers on 64 bit and 6 pointers on 32 bit architectures. Notably this new size class fits a slice header on 64 bit architectures exactly while previously a 32 byte size class would have been used for allocating a slice header on the heap. The main complexity added with this CL is that heapBitsSetType needs to handle objects that aren't 16-byte aligned but contain more than a single pointer on 64-bit architectures. Due to having a non 16 byte aligned size class on 32 bit a h.shift of 2 is now possible which means a heap bitmap byte might only be partially written. Due to this already having been possible on 64 bit before the heap bitmap code only needed minor adjustments for 32 bit doublecheck code paths. Note that this CL changes the slice capacity allocated by append for slice growth to a target capacity of 17 to 24 bytes. On 64 bit architectures the capacity of the slice returned by append([]byte{}, make([]byte, 24)...)) is 32 bytes before and 24 bytes after this CL. Depending on allocation patterns of the specific Go program this can increase the number of total alloctions as subsequent appends to the slice can trigger slice growth earlier than before. On the other side if the slice is never appended to again above its capacity this will lower heap usage by 8 bytes. This CL changes the set of size classes reported in the runtime.MemStats.BySize array due to it being limited to a total of 61 size classes. The new 24 byte size class is now included and the 20480 byte size class is not included anymore. Fixes #8885 name old time/op new time/op delta Template 196ms ± 3% 194ms ± 2% ~ (p=0.247 n=10+10) Unicode 85.6ms ±16% 88.1ms ± 1% ~ (p=0.165 n=10+10) GoTypes 673ms ± 2% 668ms ± 2% ~ (p=0.258 n=9+9) Compiler 3.14s ± 6% 3.08s ± 1% ~ (p=0.243 n=10+9) SSA 6.82s ± 1% 6.76s ± 1% -0.87% (p=0.006 n=9+10) Flate 128ms ± 7% 127ms ± 3% ~ (p=0.739 n=10+10) GoParser 154ms ± 3% 153ms ± 4% ~ (p=0.730 n=9+9) Reflect 404ms ± 1% 412ms ± 4% +1.99% (p=0.022 n=9+10) Tar 172ms ± 4% 170ms ± 4% ~ (p=0.065 n=10+9) XML 231ms ± 4% 230ms ± 3% ~ (p=0.912 n=10+10) LinkCompiler 341ms ± 1% 339ms ± 1% ~ (p=0.243 n=9+10) ExternalLinkCompiler 1.72s ± 1% 1.72s ± 1% ~ (p=0.661 n=9+10) LinkWithoutDebugCompiler 221ms ± 2% 221ms ± 2% ~ (p=0.529 n=10+10) StdCmd 18.4s ± 3% 18.2s ± 1% ~ (p=0.515 n=10+8) name old user-time/op new user-time/op delta Template 238ms ± 4% 243ms ± 6% ~ (p=0.661 n=9+10) Unicode 116ms ± 6% 113ms ± 3% -3.37% (p=0.035 n=9+10) GoTypes 854ms ± 2% 848ms ± 2% ~ (p=0.604 n=9+10) Compiler 4.10s ± 1% 4.11s ± 1% ~ (p=0.481 n=8+9) SSA 9.49s ± 1% 9.41s ± 1% -0.92% (p=0.001 n=9+10) Flate 149ms ± 6% 151ms ± 7% ~ (p=0.481 n=10+10) GoParser 189ms ± 2% 190ms ± 2% ~ (p=0.497 n=9+10) Reflect 511ms ± 2% 508ms ± 2% ~ (p=0.211 n=9+10) Tar 215ms ± 4% 212ms ± 3% ~ (p=0.105 n=10+10) XML 288ms ± 2% 288ms ± 2% ~ (p=0.971 n=10+10) LinkCompiler 559ms ± 4% 557ms ± 1% ~ (p=0.968 n=9+10) ExternalLinkCompiler 1.78s ± 1% 1.77s ± 1% ~ (p=0.055 n=8+10) LinkWithoutDebugCompiler 245ms ± 3% 245ms ± 2% ~ (p=0.684 n=10+10) name old alloc/op new alloc/op delta Template 34.8MB ± 0% 34.4MB ± 0% -0.95% (p=0.000 n=9+10) Unicode 28.6MB ± 0% 28.3MB ± 0% -0.95% (p=0.000 n=10+10) GoTypes 115MB ± 0% 114MB ± 0% -1.02% (p=0.000 n=10+9) Compiler 554MB ± 0% 549MB ± 0% -0.86% (p=0.000 n=9+10) SSA 1.28GB ± 0% 1.27GB ± 0% -0.83% (p=0.000 n=10+10) Flate 21.8MB ± 0% 21.6MB ± 0% -0.87% (p=0.000 n=8+10) GoParser 26.7MB ± 0% 26.4MB ± 0% -0.97% (p=0.000 n=10+9) Reflect 75.0MB ± 0% 74.1MB ± 0% -1.18% (p=0.000 n=10+10) Tar 32.6MB ± 0% 32.3MB ± 0% -0.94% (p=0.000 n=10+7) XML 41.5MB ± 0% 41.2MB ± 0% -0.90% (p=0.000 n=10+8) LinkCompiler 105MB ± 0% 104MB ± 0% -0.94% (p=0.000 n=10+10) ExternalLinkCompiler 153MB ± 0% 152MB ± 0% -0.69% (p=0.000 n=10+10) LinkWithoutDebugCompiler 63.7MB ± 0% 63.6MB ± 0% -0.13% (p=0.000 n=10+10) name old allocs/op new allocs/op delta Template 336k ± 0% 336k ± 0% +0.02% (p=0.002 n=10+10) Unicode 332k ± 0% 332k ± 0% ~ (p=0.447 n=10+10) GoTypes 1.16M ± 0% 1.16M ± 0% +0.01% (p=0.001 n=10+10) Compiler 4.92M ± 0% 4.92M ± 0% +0.01% (p=0.000 n=10+10) SSA 11.9M ± 0% 11.9M ± 0% +0.02% (p=0.000 n=9+10) Flate 214k ± 0% 214k ± 0% +0.02% (p=0.032 n=10+8) GoParser 270k ± 0% 270k ± 0% +0.02% (p=0.004 n=10+9) Reflect 877k ± 0% 877k ± 0% +0.01% (p=0.000 n=10+10) Tar 313k ± 0% 313k ± 0% ~ (p=0.075 n=9+10) XML 387k ± 0% 387k ± 0% +0.02% (p=0.007 n=10+10) LinkCompiler 455k ± 0% 456k ± 0% +0.08% (p=0.000 n=10+9) ExternalLinkCompiler 670k ± 0% 671k ± 0% +0.06% (p=0.000 n=10+10) LinkWithoutDebugCompiler 113k ± 0% 113k ± 0% ~ (p=0.149 n=10+10) name old maxRSS/op new maxRSS/op delta Template 34.1M ± 1% 34.1M ± 1% ~ (p=0.853 n=10+10) Unicode 35.1M ± 1% 34.6M ± 1% -1.43% (p=0.000 n=10+10) GoTypes 72.8M ± 3% 73.3M ± 2% ~ (p=0.724 n=10+10) Compiler 288M ± 3% 295M ± 4% ~ (p=0.393 n=10+10) SSA 630M ± 1% 622M ± 1% -1.18% (p=0.001 n=10+10) Flate 26.0M ± 1% 26.2M ± 2% ~ (p=0.493 n=10+10) GoParser 28.6M ± 1% 28.5M ± 2% ~ (p=0.256 n=10+10) Reflect 55.5M ± 2% 55.4M ± 1% ~ (p=0.436 n=10+10) Tar 33.0M ± 1% 32.8M ± 2% ~ (p=0.075 n=10+10) XML 38.7M ± 1% 39.0M ± 1% ~ (p=0.053 n=9+10) LinkCompiler 164M ± 1% 164M ± 1% -0.27% (p=0.029 n=10+10) ExternalLinkCompiler 174M ± 0% 173M ± 0% -0.33% (p=0.002 n=9+10) LinkWithoutDebugCompiler 137M ± 0% 136M ± 2% ~ (p=0.825 n=9+10) Change-Id: I9ecf2a10024513abef8fbfbe519e44e0b29b6167 Reviewed-on: https://go-review.googlesource.com/c/go/+/242258 Trust: Martin Möhrmann <moehrmann@google.com> Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Martin Möhrmann <martisch@uos.de> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Keith Randall <khr@golang.org>
2020-07-13 18:12:20 +02:00
var class_to_size = [_NumSizeClasses]uint16{0, 8, 16, 24, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, 240, 256, 288, 320, 352, 384, 416, 448, 480, 512, 576, 640, 704, 768, 896, 1024, 1152, 1280, 1408, 1536, 1792, 2048, 2304, 2688, 3072, 3200, 3456, 4096, 4864, 5376, 6144, 6528, 6784, 6912, 8192, 9472, 9728, 10240, 10880, 12288, 13568, 14336, 16384, 18432, 19072, 20480, 21760, 24576, 27264, 28672, 32768}
var class_to_allocnpages = [_NumSizeClasses]uint8{0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 3, 2, 3, 1, 3, 2, 3, 4, 5, 6, 1, 7, 6, 5, 4, 3, 5, 7, 2, 9, 7, 5, 8, 3, 10, 7, 4}
runtime: compute size classes statically No point in computing this info on startup. Compute it at build time. This lets us spend more time computing & checking the size classes. Improve the div magic for rounding to the start of an object. We can now use 32-bit multiplies & shifts, which should help 32-bit platforms. The static data is <1KB. The actual size classes are not changed by this CL. Change-Id: I6450cec7d1b2b4ad31fd3f945f504ed2ec6570e7 Reviewed-on: https://go-review.googlesource.com/32219 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2016-10-26 21:25:56 -07:00
type divMagic struct {
shift uint8
shift2 uint8
mul uint16
baseMask uint16
}
runtime: add 24 byte allocation size class This CL introduces a 24 byte allocation size class which fits 3 pointers on 64 bit and 6 pointers on 32 bit architectures. Notably this new size class fits a slice header on 64 bit architectures exactly while previously a 32 byte size class would have been used for allocating a slice header on the heap. The main complexity added with this CL is that heapBitsSetType needs to handle objects that aren't 16-byte aligned but contain more than a single pointer on 64-bit architectures. Due to having a non 16 byte aligned size class on 32 bit a h.shift of 2 is now possible which means a heap bitmap byte might only be partially written. Due to this already having been possible on 64 bit before the heap bitmap code only needed minor adjustments for 32 bit doublecheck code paths. Note that this CL changes the slice capacity allocated by append for slice growth to a target capacity of 17 to 24 bytes. On 64 bit architectures the capacity of the slice returned by append([]byte{}, make([]byte, 24)...)) is 32 bytes before and 24 bytes after this CL. Depending on allocation patterns of the specific Go program this can increase the number of total alloctions as subsequent appends to the slice can trigger slice growth earlier than before. On the other side if the slice is never appended to again above its capacity this will lower heap usage by 8 bytes. This CL changes the set of size classes reported in the runtime.MemStats.BySize array due to it being limited to a total of 61 size classes. The new 24 byte size class is now included and the 20480 byte size class is not included anymore. Fixes #8885 name old time/op new time/op delta Template 196ms ± 3% 194ms ± 2% ~ (p=0.247 n=10+10) Unicode 85.6ms ±16% 88.1ms ± 1% ~ (p=0.165 n=10+10) GoTypes 673ms ± 2% 668ms ± 2% ~ (p=0.258 n=9+9) Compiler 3.14s ± 6% 3.08s ± 1% ~ (p=0.243 n=10+9) SSA 6.82s ± 1% 6.76s ± 1% -0.87% (p=0.006 n=9+10) Flate 128ms ± 7% 127ms ± 3% ~ (p=0.739 n=10+10) GoParser 154ms ± 3% 153ms ± 4% ~ (p=0.730 n=9+9) Reflect 404ms ± 1% 412ms ± 4% +1.99% (p=0.022 n=9+10) Tar 172ms ± 4% 170ms ± 4% ~ (p=0.065 n=10+9) XML 231ms ± 4% 230ms ± 3% ~ (p=0.912 n=10+10) LinkCompiler 341ms ± 1% 339ms ± 1% ~ (p=0.243 n=9+10) ExternalLinkCompiler 1.72s ± 1% 1.72s ± 1% ~ (p=0.661 n=9+10) LinkWithoutDebugCompiler 221ms ± 2% 221ms ± 2% ~ (p=0.529 n=10+10) StdCmd 18.4s ± 3% 18.2s ± 1% ~ (p=0.515 n=10+8) name old user-time/op new user-time/op delta Template 238ms ± 4% 243ms ± 6% ~ (p=0.661 n=9+10) Unicode 116ms ± 6% 113ms ± 3% -3.37% (p=0.035 n=9+10) GoTypes 854ms ± 2% 848ms ± 2% ~ (p=0.604 n=9+10) Compiler 4.10s ± 1% 4.11s ± 1% ~ (p=0.481 n=8+9) SSA 9.49s ± 1% 9.41s ± 1% -0.92% (p=0.001 n=9+10) Flate 149ms ± 6% 151ms ± 7% ~ (p=0.481 n=10+10) GoParser 189ms ± 2% 190ms ± 2% ~ (p=0.497 n=9+10) Reflect 511ms ± 2% 508ms ± 2% ~ (p=0.211 n=9+10) Tar 215ms ± 4% 212ms ± 3% ~ (p=0.105 n=10+10) XML 288ms ± 2% 288ms ± 2% ~ (p=0.971 n=10+10) LinkCompiler 559ms ± 4% 557ms ± 1% ~ (p=0.968 n=9+10) ExternalLinkCompiler 1.78s ± 1% 1.77s ± 1% ~ (p=0.055 n=8+10) LinkWithoutDebugCompiler 245ms ± 3% 245ms ± 2% ~ (p=0.684 n=10+10) name old alloc/op new alloc/op delta Template 34.8MB ± 0% 34.4MB ± 0% -0.95% (p=0.000 n=9+10) Unicode 28.6MB ± 0% 28.3MB ± 0% -0.95% (p=0.000 n=10+10) GoTypes 115MB ± 0% 114MB ± 0% -1.02% (p=0.000 n=10+9) Compiler 554MB ± 0% 549MB ± 0% -0.86% (p=0.000 n=9+10) SSA 1.28GB ± 0% 1.27GB ± 0% -0.83% (p=0.000 n=10+10) Flate 21.8MB ± 0% 21.6MB ± 0% -0.87% (p=0.000 n=8+10) GoParser 26.7MB ± 0% 26.4MB ± 0% -0.97% (p=0.000 n=10+9) Reflect 75.0MB ± 0% 74.1MB ± 0% -1.18% (p=0.000 n=10+10) Tar 32.6MB ± 0% 32.3MB ± 0% -0.94% (p=0.000 n=10+7) XML 41.5MB ± 0% 41.2MB ± 0% -0.90% (p=0.000 n=10+8) LinkCompiler 105MB ± 0% 104MB ± 0% -0.94% (p=0.000 n=10+10) ExternalLinkCompiler 153MB ± 0% 152MB ± 0% -0.69% (p=0.000 n=10+10) LinkWithoutDebugCompiler 63.7MB ± 0% 63.6MB ± 0% -0.13% (p=0.000 n=10+10) name old allocs/op new allocs/op delta Template 336k ± 0% 336k ± 0% +0.02% (p=0.002 n=10+10) Unicode 332k ± 0% 332k ± 0% ~ (p=0.447 n=10+10) GoTypes 1.16M ± 0% 1.16M ± 0% +0.01% (p=0.001 n=10+10) Compiler 4.92M ± 0% 4.92M ± 0% +0.01% (p=0.000 n=10+10) SSA 11.9M ± 0% 11.9M ± 0% +0.02% (p=0.000 n=9+10) Flate 214k ± 0% 214k ± 0% +0.02% (p=0.032 n=10+8) GoParser 270k ± 0% 270k ± 0% +0.02% (p=0.004 n=10+9) Reflect 877k ± 0% 877k ± 0% +0.01% (p=0.000 n=10+10) Tar 313k ± 0% 313k ± 0% ~ (p=0.075 n=9+10) XML 387k ± 0% 387k ± 0% +0.02% (p=0.007 n=10+10) LinkCompiler 455k ± 0% 456k ± 0% +0.08% (p=0.000 n=10+9) ExternalLinkCompiler 670k ± 0% 671k ± 0% +0.06% (p=0.000 n=10+10) LinkWithoutDebugCompiler 113k ± 0% 113k ± 0% ~ (p=0.149 n=10+10) name old maxRSS/op new maxRSS/op delta Template 34.1M ± 1% 34.1M ± 1% ~ (p=0.853 n=10+10) Unicode 35.1M ± 1% 34.6M ± 1% -1.43% (p=0.000 n=10+10) GoTypes 72.8M ± 3% 73.3M ± 2% ~ (p=0.724 n=10+10) Compiler 288M ± 3% 295M ± 4% ~ (p=0.393 n=10+10) SSA 630M ± 1% 622M ± 1% -1.18% (p=0.001 n=10+10) Flate 26.0M ± 1% 26.2M ± 2% ~ (p=0.493 n=10+10) GoParser 28.6M ± 1% 28.5M ± 2% ~ (p=0.256 n=10+10) Reflect 55.5M ± 2% 55.4M ± 1% ~ (p=0.436 n=10+10) Tar 33.0M ± 1% 32.8M ± 2% ~ (p=0.075 n=10+10) XML 38.7M ± 1% 39.0M ± 1% ~ (p=0.053 n=9+10) LinkCompiler 164M ± 1% 164M ± 1% -0.27% (p=0.029 n=10+10) ExternalLinkCompiler 174M ± 0% 173M ± 0% -0.33% (p=0.002 n=9+10) LinkWithoutDebugCompiler 137M ± 0% 136M ± 2% ~ (p=0.825 n=9+10) Change-Id: I9ecf2a10024513abef8fbfbe519e44e0b29b6167 Reviewed-on: https://go-review.googlesource.com/c/go/+/242258 Trust: Martin Möhrmann <moehrmann@google.com> Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Martin Möhrmann <martisch@uos.de> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Keith Randall <khr@golang.org>
2020-07-13 18:12:20 +02:00
var class_to_divmagic = [_NumSizeClasses]divMagic{{0, 0, 0, 0}, {3, 0, 1, 65528}, {4, 0, 1, 65520}, {3, 11, 683, 0}, {5, 0, 1, 65504}, {4, 11, 683, 0}, {6, 0, 1, 65472}, {4, 10, 205, 0}, {5, 9, 171, 0}, {4, 11, 293, 0}, {7, 0, 1, 65408}, {4, 13, 911, 0}, {5, 10, 205, 0}, {4, 12, 373, 0}, {6, 9, 171, 0}, {4, 13, 631, 0}, {5, 11, 293, 0}, {4, 13, 547, 0}, {8, 0, 1, 65280}, {5, 9, 57, 0}, {6, 9, 103, 0}, {5, 12, 373, 0}, {7, 7, 43, 0}, {5, 10, 79, 0}, {6, 10, 147, 0}, {5, 11, 137, 0}, {9, 0, 1, 65024}, {6, 9, 57, 0}, {7, 9, 103, 0}, {6, 11, 187, 0}, {8, 7, 43, 0}, {7, 8, 37, 0}, {10, 0, 1, 64512}, {7, 9, 57, 0}, {8, 6, 13, 0}, {7, 11, 187, 0}, {9, 5, 11, 0}, {8, 8, 37, 0}, {11, 0, 1, 63488}, {8, 9, 57, 0}, {7, 10, 49, 0}, {10, 5, 11, 0}, {7, 10, 41, 0}, {7, 9, 19, 0}, {12, 0, 1, 61440}, {8, 9, 27, 0}, {8, 10, 49, 0}, {11, 5, 11, 0}, {7, 13, 161, 0}, {7, 13, 155, 0}, {8, 9, 19, 0}, {13, 0, 1, 57344}, {8, 12, 111, 0}, {9, 9, 27, 0}, {11, 6, 13, 0}, {7, 14, 193, 0}, {12, 3, 3, 0}, {8, 13, 155, 0}, {11, 8, 37, 0}, {14, 0, 1, 49152}, {11, 8, 29, 0}, {7, 13, 55, 0}, {12, 5, 7, 0}, {8, 14, 193, 0}, {13, 3, 3, 0}, {7, 14, 77, 0}, {12, 7, 19, 0}, {15, 0, 1, 32768}}
var size_to_class8 = [smallSizeMax/smallSizeDiv + 1]uint8{0, 1, 2, 3, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 23, 23, 23, 23, 24, 24, 24, 24, 25, 25, 25, 25, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 28, 28, 28, 28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 29, 29, 29, 30, 30, 30, 30, 30, 30, 30, 30, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32}
var size_to_class128 = [(_MaxSmallSize-smallSizeMax)/largeSizeDiv + 1]uint8{32, 33, 34, 35, 36, 37, 37, 38, 38, 39, 39, 40, 40, 40, 41, 41, 41, 42, 43, 43, 44, 44, 44, 44, 44, 45, 45, 45, 45, 45, 45, 46, 46, 46, 46, 47, 47, 47, 47, 47, 47, 48, 48, 48, 49, 49, 50, 51, 51, 51, 51, 51, 51, 51, 51, 51, 51, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 53, 53, 54, 54, 54, 54, 55, 55, 55, 55, 55, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 57, 57, 57, 57, 57, 57, 57, 57, 57, 57, 58, 58, 58, 58, 58, 58, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 61, 61, 61, 61, 61, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 62, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 66, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67, 67}
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