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>
diff --git a/src/runtime/mgc0.go b/src/runtime/mgc0.go
index 91c3d58..bbd786d 100644
--- a/src/runtime/mgc0.go
+++ b/src/runtime/mgc0.go
@@ -25,21 +25,6 @@
poolcleanup()
}
- // Clear central defer pools.
- // Leave per-P pools alone, they have strictly bounded size.
- lock(&sched.deferlock)
- for i := range sched.deferpool {
- // disconnect cached list before dropping it on the floor,
- // so that a dangling ref to one entry does not pin all of them.
- var d, dlink *_defer
- for d = sched.deferpool[i]; d != nil; d = dlink {
- dlink = d.link
- d.link = nil
- }
- sched.deferpool[i] = nil
- }
- unlock(&sched.deferlock)
-
for _, p := range &allp {
if p == nil {
break
@@ -58,6 +43,18 @@
}
c.sudogcache = nil
}
+
+ // clear defer pools
+ for i := range p.deferpool {
+ // disconnect cached list before dropping it on the floor,
+ // so that a dangling ref to one entry does not pin all of them.
+ var d, dlink *_defer
+ for d = p.deferpool[i]; d != nil; d = dlink {
+ dlink = d.link
+ d.link = nil
+ }
+ p.deferpool[i] = nil
+ }
}
}
diff --git a/src/runtime/panic.go b/src/runtime/panic.go
index c8cfd9f..e2a5c62 100644
--- a/src/runtime/panic.go
+++ b/src/runtime/panic.go
@@ -166,20 +166,9 @@
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 @@
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)
}
}
diff --git a/src/runtime/proc1.go b/src/runtime/proc1.go
index 2dc3a97..70addbf 100644
--- a/src/runtime/proc1.go
+++ b/src/runtime/proc1.go
@@ -2470,9 +2470,6 @@
pp = new(p)
pp.id = i
pp.status = _Pgcstop
- for i := range pp.deferpool {
- pp.deferpool[i] = pp.deferpoolbuf[i][:0]
- }
atomicstorep(unsafe.Pointer(&allp[i]), unsafe.Pointer(pp))
}
if pp.mcache == nil {
@@ -2511,13 +2508,6 @@
}
sched.runqsize++
}
- for i := range p.deferpool {
- for j := range p.deferpoolbuf[i] {
- p.deferpoolbuf[i][j] = nil
- }
- p.deferpool[i] = p.deferpoolbuf[i][:0]
- }
-
freemcache(p.mcache)
p.mcache = nil
gfpurge(p)
diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go
index 52817c0..e38d11a 100644
--- a/src/runtime/runtime2.go
+++ b/src/runtime/runtime2.go
@@ -314,9 +314,7 @@
syscalltick uint32 // incremented on every system call
m *m // back-link to associated m (nil if idle)
mcache *mcache
-
- deferpool [5][]*_defer // pool of available defer structs of different sizes (see panic.go)
- deferpoolbuf [5][32]*_defer
+ deferpool [5]*_defer // pool of available defer structs of different sizes (see panic.c)
// Cache of goroutine ids, amortizes accesses to runtime·sched.goidgen.
goidcache uint64
@@ -367,9 +365,6 @@
gfree *g
ngfree int32
- deferlock mutex
- deferpool [5]*_defer // central pool of available defer structs of different sizes
-
gcwaiting uint32 // gc is waiting to run
stopwait int32
stopnote note
