46664 2010-09-27 15:25:55 -0700 6% Array Push and Pop Overhead in v8-deltablue 2010-09-28 10:04:48 -0700 1 1 1 Unclassified WebKit JavaScriptCore 528+ (Nightly build) All OS X 10.6 RESOLVED FIXED P2 Normal --- 1 msaboff msaboff ager commit-queue eric oldest_to_newest 285799 0 msaboff 2010-09-27 15:25:55 -0700 The v8 benchmark component deltablue has an overhead of 6% in the array push and pop routines and descendants. 285811 1 68980 msaboff 2010-09-27 15:36:52 -0700 Created attachment 68980 Patch to Allocate Minimal Space for Array() Changes the JSArray() constructor that takes an ArgList argument to allocate space for three elements when the ArgList is empty. This improves v8-deltablue by about 2.8% 285888 2 68980 ggaren 2010-09-27 16:45:56 -0700 Comment on attachment 68980 Patch to Allocate Minimal Space for Array() r=me 285989 3 eric 2010-09-27 18:49:12 -0700 Curious if a larger number wouldn't be better. I assume you tested a variety of sizes? I wonder what V8 does here. 285991 4 68980 commit-queue 2010-09-27 18:52:54 -0700 Comment on attachment 68980 Patch to Allocate Minimal Space for Array() Clearing flags on attachment: 68980 Committed r68469: <http://trac.webkit.org/changeset/68469> 285992 5 commit-queue 2010-09-27 18:52:58 -0700 All reviewed patches have been landed. Closing bug. 286319 6 msaboff 2010-09-28 10:04:48 -0700 In response to comment from eric@webkit.org, I tried values of 1 through 4. It appears that there is a knee at 3 as it was better than the other values. I suspect that the initialization overhead hurts as the value goes higher (the JSValue() constructor is called for each allocated element). 68980 2010-09-27 15:36:52 -0700 2010-09-27 18:52:54 -0700 Patch to Allocate Minimal Space for Array() 46664.patch text/plain 2359 msaboff SW5kZXg6IEphdmFTY3JpcHRDb3JlL0NoYW5nZUxvZwo9PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09Ci0tLSBKYXZhU2NyaXB0 Q29yZS9DaGFuZ2VMb2cJKHJldmlzaW9uIDY4NDI5KQorKysgSmF2YVNjcmlwdENvcmUvQ2hhbmdl TG9nCSh3b3JraW5nIGNvcHkpCkBAIC0xLDMgKzEsMTYgQEAKKzIwMTAtMDktMjcgIE1pY2hhZWwg U2Fib2ZmICA8bXNhYm9mZkBhcHBsZS5jb20+CisKKyAgICAgICAgUmV2aWV3ZWQgYnkgTk9CT0RZ IChPT1BTISkuCisKKyAgICAgICAgQ2hhbmdlZCB0aGUgaW5pdGlhbGl6YXRpb24gb2YgSlNBcnJh eSBvYmplY3RzIHRvIGhhdmUgc3BhY2UgZm9yIAorICAgICAgICAzIGVsZW1lbnRzIGZvciB0aGUg Y29uc3RydWN0b3IgdGhhdCB0YWtlcyBhIEFyZ0xpc3QgYXJndW1lbnQuCisgICAgICAgIFRoaXMg aW1wcm92ZXMgdjgtZGVsdGFibHVlIHBlcmZvcm1hbmNlIGJ5IGFib3V0IDIuOCUgYnkgcmVkdWNp bmcgCisgICAgICAgIHRoZSBudW1iZXIgb2YgcmVhbGxvYygpIGNhbGxzLgorICAgICAgICBodHRw czovL2J1Z3Mud2Via2l0Lm9yZy9zaG93X2J1Zy5jZ2k/aWQ9NDY2NjQKKworICAgICAgICAqIHJ1 bnRpbWUvSlNBcnJheS5jcHA6CisgICAgICAgIChKU0M6OkpTQXJyYXk6OkpTQXJyYXkpOgorCiAy MDEwLTA5LTI3ICBBbmRlcnMgQ2FybHNzb24gIDxhbmRlcnNjYUBhcHBsZS5jb20+CiAKICAgICAg ICAgRml4IHRoaW5rby4KSW5kZXg6IEphdmFTY3JpcHRDb3JlL3J1bnRpbWUvSlNBcnJheS5jcHAK PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PQotLS0gSmF2YVNjcmlwdENvcmUvcnVudGltZS9KU0FycmF5LmNwcAkocmV2aXNp b24gNjg0MjkpCisrKyBKYXZhU2NyaXB0Q29yZS9ydW50aW1lL0pTQXJyYXkuY3BwCSh3b3JraW5n IGNvcHkpCkBAIC0yMDIsMTIgKzIwMiwyMCBAQCBKU0FycmF5OjpKU0FycmF5KE5vbk51bGxQYXNz UmVmUHRyPFN0cnVjCiAgICAgOiBKU09iamVjdChzdHJ1Y3R1cmUpCiB7CiAgICAgdW5zaWduZWQg aW5pdGlhbENhcGFjaXR5ID0gbGlzdC5zaXplKCk7Ci0KLSAgICBtX3N0b3JhZ2UgPSBzdGF0aWNf Y2FzdDxBcnJheVN0b3JhZ2UqPihmYXN0TWFsbG9jKHN0b3JhZ2VTaXplKGluaXRpYWxDYXBhY2l0 eSkpKTsKKyAgICB1bnNpZ25lZCBpbml0aWFsU3RvcmFnZTsKKyAgICAKKyAgICAvLyBJZiB0aGUg QXJnTGlzdCBpcyBlbXB0eSwgYWxsb2NhdGUgc3BhY2UgZm9yIDMgZW50cmllcy4gIFRoaXMgdmFs dWUgZW1waXJpY2FsbHkKKyAgICAvLyB3b3JrcyB3ZWxsIGZvciBiZW5jaG1hcmtzLgorICAgIGlm ICghaW5pdGlhbENhcGFjaXR5KQorICAgICAgICBpbml0aWFsU3RvcmFnZSA9IDM7CisgICAgZWxz ZQorICAgICAgICBpbml0aWFsU3RvcmFnZSA9IGluaXRpYWxDYXBhY2l0eTsKKyAgICAKKyAgICBt X3N0b3JhZ2UgPSBzdGF0aWNfY2FzdDxBcnJheVN0b3JhZ2UqPihmYXN0TWFsbG9jKHN0b3JhZ2VT aXplKGluaXRpYWxTdG9yYWdlKSkpOwogICAgIG1fc3RvcmFnZS0+bV9hbGxvY0Jhc2UgPSBtX3N0 b3JhZ2U7CiAgICAgbV9pbmRleEJpYXMgPSAwOwogICAgIG1fc3RvcmFnZS0+bV9sZW5ndGggPSBp bml0aWFsQ2FwYWNpdHk7Ci0gICAgbV92ZWN0b3JMZW5ndGggPSBpbml0aWFsQ2FwYWNpdHk7Cisg ICAgbV92ZWN0b3JMZW5ndGggPSBpbml0aWFsU3RvcmFnZTsKICAgICBtX3N0b3JhZ2UtPm1fbnVt VmFsdWVzSW5WZWN0b3IgPSBpbml0aWFsQ2FwYWNpdHk7CiAgICAgbV9zdG9yYWdlLT5tX3NwYXJz ZVZhbHVlTWFwID0gMDsKICAgICBtX3N0b3JhZ2UtPnN1YmNsYXNzRGF0YSA9IDA7CkBAIC0yMjEs MTAgKzIyOSwxMiBAQCBKU0FycmF5OjpKU0FycmF5KE5vbk51bGxQYXNzUmVmUHRyPFN0cnVjCiAg ICAgQXJnTGlzdDo6Y29uc3RfaXRlcmF0b3IgZW5kID0gbGlzdC5lbmQoKTsKICAgICBmb3IgKEFy Z0xpc3Q6OmNvbnN0X2l0ZXJhdG9yIGl0ID0gbGlzdC5iZWdpbigpOyBpdCAhPSBlbmQ7ICsraXQs ICsraSkKICAgICAgICAgdmVjdG9yW2ldID0gKml0OworICAgIGZvciAoOyBpIDwgaW5pdGlhbFN0 b3JhZ2U7IGkrKykKKyAgICAgICAgdmVjdG9yW2ldID0gSlNWYWx1ZSgpOwogCiAgICAgY2hlY2tD b25zaXN0ZW5jeSgpOwogCi0gICAgSGVhcDo6aGVhcCh0aGlzKS0+cmVwb3J0RXh0cmFNZW1vcnlD b3N0KHN0b3JhZ2VTaXplKGluaXRpYWxDYXBhY2l0eSkpOworICAgIEhlYXA6OmhlYXAodGhpcykt PnJlcG9ydEV4dHJhTWVtb3J5Q29zdChzdG9yYWdlU2l6ZShpbml0aWFsU3RvcmFnZSkpOwogfQog CiBKU0FycmF5Ojp+SlNBcnJheSgpCg==