Revert "runtime: bound defer pools"

This reverts commit 805907115352801a54f987fc9079251b478cce3f.

Conflicts:
	src/runtime/proc1.go (resolved by hand)

Change-Id: Ic62e3e802f0007ff9012b37bc5fd41fcafc153d0
Reviewed-on: https://go-review.googlesource.com/3885
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>

1 files changed, 5 insertions, 35 deletions

diff --git a/src/runtime/panic.go b/src/runtime/panic.go
index c8cfd9f0c8..e2a5c629da 100644
--- a/src/runtime/panic.go
+++ b/src/runtime/panic.go
@@ -166,20 +166,9 @@ func newdefer(siz int32) *_defer {
 	mp := acquirem()
 	if sc < uintptr(len(p{}.deferpool)) {
 		pp := mp.p
-		if len(pp.deferpool[sc]) == 0 {
-			lock(&sched.deferlock)
-			for len(pp.deferpool[sc]) < cap(pp.deferpool[sc])/2 && sched.deferpool[sc] != nil {
-				d := sched.deferpool[sc]
-				sched.deferpool[sc] = d.link
-				d.link = nil
-				pp.deferpool[sc] = append(pp.deferpool[sc], d)
-			}
-			unlock(&sched.deferlock)
-		}
-		if ln := len(pp.deferpool[sc]); ln > 0 {
-			d = pp.deferpool[sc][ln-1]
-			pp.deferpool[sc][ln-1] = nil
-			pp.deferpool[sc] = pp.deferpool[sc][:ln-1]
+		d = pp.deferpool[sc]
+		if d != nil {
+			pp.deferpool[sc] = d.link
 		}
 	}
 	if d == nil {
@@ -225,28 +214,9 @@ func freedefer(d *_defer) {
 	if sc < uintptr(len(p{}.deferpool)) {
 		mp := acquirem()
 		pp := mp.p
-		if len(pp.deferpool[sc]) == cap(pp.deferpool[sc]) {
-			// Transfer half of local cache to the central cache.
-			var first, last *_defer
-			for len(pp.deferpool[sc]) > cap(pp.deferpool[sc])/2 {
-				ln := len(pp.deferpool[sc])
-				d := pp.deferpool[sc][ln-1]
-				pp.deferpool[sc][ln-1] = nil
-				pp.deferpool[sc] = pp.deferpool[sc][:ln-1]
-				if first == nil {
-					first = d
-				} else {
-					last.link = d
-				}
-				last = d
-			}
-			lock(&sched.deferlock)
-			last.link = sched.deferpool[sc]
-			sched.deferpool[sc] = first
-			unlock(&sched.deferlock)
-		}
 		*d = _defer{}
-		pp.deferpool[sc] = append(pp.deferpool[sc], d)
+		d.link = pp.deferpool[sc]
+		pp.deferpool[sc] = d
 		releasem(mp)
 	}
 }