From: Michael Anthony Knyszek <mknyszek@google.com>
Date: Wed, 4 Dec 2024 19:22:51 +0000 (+0000)
Subject: doc/next: add release notes for runtime and sync
X-Git-Tag: go1.24rc1~30
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=795d95d6ba3f92091f55af81f8ee840048fb2499;p=gostls13.git

doc/next: add release notes for runtime and sync

Also, move the weak package heading to the end; it currently overlaps
with 1-osroot.md in the sort order.

For #68545.

Change-Id: Ia26ae511eaab7c8762e42d1593ac2197d25bbadb
Reviewed-on: https://go-review.googlesource.com/c/go/+/633599
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
---

diff --git a/doc/next/4-runtime.md b/doc/next/4-runtime.md
index 1f8e445e0b..7079a0107f 100644
--- a/doc/next/4-runtime.md
+++ b/doc/next/4-runtime.md
@@ -1 +1,17 @@
 ## Runtime {#runtime}
+
+<!-- go.dev/issue/54766 -->
+<!-- go.dev/cl/614795 -->
+<!-- go.dev/issue/68578 -->
+
+Several performance improvements to the runtime have decreased CPU overheads by
+2—3% on average across a suite of representative benchmarks.
+Results may vary by application.
+These improvements include a new builtin `map` implementation based on
+[Swiss Tables](https://abseil.io/about/design/swisstables), more efficient
+memory allocation of small objects, and a new runtime-internal mutex
+implementation.
+
+The new builtin `map` implementation and new runtime-internal mutex may be
+disabled by setting `GOEXPERIMENT=noswissmap` and `GOEXPERIMENT=nospinbitmutex`
+at build time respectively.
diff --git a/doc/next/6-stdlib/1-weak.md b/doc/next/6-stdlib/6-weak.md
similarity index 100%
rename from doc/next/6-stdlib/1-weak.md
rename to doc/next/6-stdlib/6-weak.md
diff --git a/doc/next/6-stdlib/99-minor/sync/70683.md b/doc/next/6-stdlib/99-minor/sync/70683.md
new file mode 100644
index 0000000000..f88f3889e2
--- /dev/null
+++ b/doc/next/6-stdlib/99-minor/sync/70683.md
@@ -0,0 +1,5 @@
+The implementation of [sync.Map] has been changed, improving overall performance
+and resolving some long-standing issues.
+If you encounter any problems, set `GOEXPERIMENT=nosynchashtriemap` at build
+time to switch back to the old implementation and please [file an
+issue](/issue/new).