mirror of
https://github.com/golang/go
synced 2024-09-18 15:32:18 +00:00
runtime: switch default stack size back to 8kB
The move from 4kB to 8kB in Go 1.2 was to eliminate many stack split hot spots. The move back to 4kB was predicated on copying stacks eliminating the potential for hot spots. Unfortunately, the fact that stacks do not copy 100% of the time means that hot spots can still happen under the right conditions, and the slowdown is worse now than it was in Go 1.2. There is a real program in issue 8030 that sees about a 30x slowdown: it has a reflect call near the top of the stack which inhibits any stack copying on that segment. Go back to 8kB until stack copying can be used 100% of the time. Fixes #8030. LGTM=khr, dave, iant R=iant, khr, r, bradfitz, dave CC=golang-codereviews https://golang.org/cl/92540043
This commit is contained in:
parent
60be4a2450
commit
6aee29648f
|
@ -118,13 +118,6 @@ Details including performance numbers are in this
|
|||
<a href="http://golang.org/s/contigstacks">design document</a>.
|
||||
</p>
|
||||
|
||||
<h3 id="stack_size">Stack size</h3>
|
||||
|
||||
<p>
|
||||
Go 1.2 increased the minimum stack size to 8 kilobytes; with the new stack model, it has been
|
||||
put back to 4 kilobytes.
|
||||
</p>
|
||||
|
||||
<h3 id="garbage_collector">Changes to the garbage collector</h3>
|
||||
|
||||
<p>
|
||||
|
|
|
@ -76,7 +76,7 @@ enum {
|
|||
// The minimum stack segment size to allocate.
|
||||
// If the amount needed for the splitting frame + StackExtra
|
||||
// is less than this number, the stack will have this size instead.
|
||||
StackMin = 4096,
|
||||
StackMin = 8192,
|
||||
StackSystemRounded = StackSystem + (-StackSystem & (StackMin-1)),
|
||||
FixedStack = StackMin + StackSystemRounded,
|
||||
|
||||
|
|
Loading…
Reference in a new issue