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authorgVisor bot <gvisor-bot@google.com>2019-06-10 22:42:41 +0000
committergVisor bot <gvisor-bot@google.com>2019-06-10 22:42:41 +0000
commit8390a8227b571e82c42e3e90aa28a7b86f7e3f9b (patch)
tree8bfad5169182b7ba1c6ed5f3df0279729cc200b0 /pkg/sentry/pgalloc
parent4f56f1bf2248bb17da8b269b4191218d85ce6587 (diff)
parenta00157cc0e216a9829f2659ce35c856a22aa5ba2 (diff)
Merge a00157cc (automated)
Diffstat (limited to 'pkg/sentry/pgalloc')
-rw-r--r--pkg/sentry/pgalloc/pgalloc.go63
1 files changed, 54 insertions, 9 deletions
diff --git a/pkg/sentry/pgalloc/pgalloc.go b/pkg/sentry/pgalloc/pgalloc.go
index 2b9924ad7..6d91f1a7b 100644
--- a/pkg/sentry/pgalloc/pgalloc.go
+++ b/pkg/sentry/pgalloc/pgalloc.go
@@ -32,6 +32,7 @@ import (
"gvisor.googlesource.com/gvisor/pkg/log"
"gvisor.googlesource.com/gvisor/pkg/sentry/context"
+ "gvisor.googlesource.com/gvisor/pkg/sentry/hostmm"
"gvisor.googlesource.com/gvisor/pkg/sentry/platform"
"gvisor.googlesource.com/gvisor/pkg/sentry/safemem"
"gvisor.googlesource.com/gvisor/pkg/sentry/usage"
@@ -162,6 +163,11 @@ type MemoryFile struct {
// evictionWG counts the number of goroutines currently performing evictions.
evictionWG sync.WaitGroup
+
+ // stopNotifyPressure stops memory cgroup pressure level
+ // notifications used to drive eviction. stopNotifyPressure is
+ // immutable.
+ stopNotifyPressure func()
}
// MemoryFileOpts provides options to NewMemoryFile.
@@ -169,6 +175,11 @@ type MemoryFileOpts struct {
// DelayedEviction controls the extent to which the MemoryFile may delay
// eviction of evictable allocations.
DelayedEviction DelayedEvictionType
+
+ // If UseHostMemcgPressure is true, use host memory cgroup pressure level
+ // notifications to determine when eviction is necessary. This option has
+ // no effect unless DelayedEviction is DelayedEvictionEnabled.
+ UseHostMemcgPressure bool
}
// DelayedEvictionType is the type of MemoryFileOpts.DelayedEviction.
@@ -186,9 +197,14 @@ const (
// evictable allocations until doing so is considered necessary to avoid
// performance degradation due to host memory pressure, or OOM kills.
//
- // As of this writing, DelayedEvictionEnabled delays evictions until the
- // reclaimer goroutine is out of work (pages to reclaim), then evicts all
- // pending evictable allocations immediately.
+ // As of this writing, the behavior of DelayedEvictionEnabled depends on
+ // whether or not MemoryFileOpts.UseHostMemcgPressure is enabled:
+ //
+ // - If UseHostMemcgPressure is true, evictions are delayed until memory
+ // pressure is indicated.
+ //
+ // - Otherwise, evictions are only delayed until the reclaimer goroutine
+ // is out of work (pages to reclaim).
DelayedEvictionEnabled
// DelayedEvictionManual requires that evictable allocations are only
@@ -292,6 +308,22 @@ func NewMemoryFile(file *os.File, opts MemoryFileOpts) (*MemoryFile, error) {
}
f.mappings.Store(make([]uintptr, initialSize/chunkSize))
f.reclaimCond.L = &f.mu
+
+ if f.opts.DelayedEviction == DelayedEvictionEnabled && f.opts.UseHostMemcgPressure {
+ stop, err := hostmm.NotifyCurrentMemcgPressureCallback(func() {
+ f.mu.Lock()
+ startedAny := f.startEvictionsLocked()
+ f.mu.Unlock()
+ if startedAny {
+ log.Debugf("pgalloc.MemoryFile performing evictions due to memcg pressure")
+ }
+ }, "low")
+ if err != nil {
+ return nil, fmt.Errorf("failed to configure memcg pressure level notifications: %v", err)
+ }
+ f.stopNotifyPressure = stop
+ }
+
go f.runReclaim() // S/R-SAFE: f.mu
// The Linux kernel contains an optional feature called "Integrity
@@ -692,9 +724,11 @@ func (f *MemoryFile) MarkEvictable(user EvictableMemoryUser, er EvictableRange)
// Kick off eviction immediately.
f.startEvictionGoroutineLocked(user, info)
case DelayedEvictionEnabled:
- // Ensure that the reclaimer goroutine is running, so that it can
- // start eviction when necessary.
- f.reclaimCond.Signal()
+ if !f.opts.UseHostMemcgPressure {
+ // Ensure that the reclaimer goroutine is running, so that it
+ // can start eviction when necessary.
+ f.reclaimCond.Signal()
+ }
}
}
}
@@ -992,11 +1026,12 @@ func (f *MemoryFile) runReclaim() {
}
f.markReclaimed(fr)
}
+
// We only get here if findReclaimable finds f.destroyed set and returns
// false.
f.mu.Lock()
- defer f.mu.Unlock()
if !f.destroyed {
+ f.mu.Unlock()
panic("findReclaimable broke out of reclaim loop, but destroyed is no longer set")
}
f.file.Close()
@@ -1016,6 +1051,13 @@ func (f *MemoryFile) runReclaim() {
}
// Similarly, invalidate f.mappings. (atomic.Value.Store(nil) panics.)
f.mappings.Store([]uintptr{})
+ f.mu.Unlock()
+
+ // This must be called without holding f.mu to avoid circular lock
+ // ordering.
+ if f.stopNotifyPressure != nil {
+ f.stopNotifyPressure()
+ }
}
func (f *MemoryFile) findReclaimable() (platform.FileRange, bool) {
@@ -1029,7 +1071,7 @@ func (f *MemoryFile) findReclaimable() (platform.FileRange, bool) {
if f.reclaimable {
break
}
- if f.opts.DelayedEviction == DelayedEvictionEnabled {
+ if f.opts.DelayedEviction == DelayedEvictionEnabled && !f.opts.UseHostMemcgPressure {
// No work to do. Evict any pending evictable allocations to
// get more reclaimable pages before going to sleep.
f.startEvictionsLocked()
@@ -1089,14 +1131,17 @@ func (f *MemoryFile) StartEvictions() {
}
// Preconditions: f.mu must be locked.
-func (f *MemoryFile) startEvictionsLocked() {
+func (f *MemoryFile) startEvictionsLocked() bool {
+ startedAny := false
for user, info := range f.evictable {
// Don't start multiple goroutines to evict the same user's
// allocations.
if !info.evicting {
f.startEvictionGoroutineLocked(user, info)
+ startedAny = true
}
}
+ return startedAny
}
// Preconditions: info == f.evictable[user]. !info.evicting. f.mu must be