diff options
Diffstat (limited to 'pkg/sentry/pgalloc')
| -rw-r--r-- | pkg/sentry/pgalloc/BUILD | 3 | ||||
| -rw-r--r-- | pkg/sentry/pgalloc/pgalloc.go | 63 |
2 files changed, 56 insertions, 10 deletions
diff --git a/pkg/sentry/pgalloc/BUILD b/pkg/sentry/pgalloc/BUILD index 8a8a0e4e4..ca2d5ba6f 100644 --- a/pkg/sentry/pgalloc/BUILD +++ b/pkg/sentry/pgalloc/BUILD @@ -63,9 +63,10 @@ go_library( visibility = ["//pkg/sentry:internal"], deps = [ "//pkg/log", + "//pkg/memutil", "//pkg/sentry/arch", "//pkg/sentry/context", - "//pkg/sentry/memutil", + "//pkg/sentry/hostmm", "//pkg/sentry/platform", "//pkg/sentry/safemem", "//pkg/sentry/usage", 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 |