[compiler-rt] 32be340 - [scudo] Add a fast get time version.

[Christopher Ferris via llvm-commits]

Author: Christopher Ferris
Date: 2023-03-09T14:12:53-08:00
New Revision: 32be3405f57f1e4d0ec0da943434113450583e89

URL: https://github.com/llvm/llvm-project/commit/32be3405f57f1e4d0ec0da943434113450583e89
DIFF: https://github.com/llvm/llvm-project/commit/32be3405f57f1e4d0ec0da943434113450583e89.diff

LOG: [scudo] Add a fast get time version.

On Android, the _COARSE version of clock_gettime is about twice as fast.
Therefore, add a getMonotonicTimeFast function that is used in the
releaseToOSMaybe functions.

Reviewed By: Chia-hungDuan

Differential Revision: https://reviews.llvm.org/D145636

Added: 
    

Modified: 
    compiler-rt/lib/scudo/standalone/common.h
    compiler-rt/lib/scudo/standalone/fuchsia.cpp
    compiler-rt/lib/scudo/standalone/linux.cpp
    compiler-rt/lib/scudo/standalone/primary32.h
    compiler-rt/lib/scudo/standalone/primary64.h
    compiler-rt/lib/scudo/standalone/trusty.cpp

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/scudo/standalone/common.h b/compiler-rt/lib/scudo/standalone/common.h
index aa15e9e787e2e..e1ca264f46a69 100644
--- a/compiler-rt/lib/scudo/standalone/common.h
+++ b/compiler-rt/lib/scudo/standalone/common.h
@@ -147,6 +147,9 @@ const char *getEnv(const char *Name);
 uptr GetRSS();
 
 u64 getMonotonicTime();
+// Gets the time faster but with less accuracy. Can call getMonotonicTime
+// if no fast version is available.
+u64 getMonotonicTimeFast();
 
 u32 getThreadID();
 

diff  --git a/compiler-rt/lib/scudo/standalone/fuchsia.cpp b/compiler-rt/lib/scudo/standalone/fuchsia.cpp
index 6aae03b7c2106..ef93542ef62c3 100644
--- a/compiler-rt/lib/scudo/standalone/fuchsia.cpp
+++ b/compiler-rt/lib/scudo/standalone/fuchsia.cpp
@@ -200,6 +200,7 @@ void HybridMutex::unlock() __TA_NO_THREAD_SAFETY_ANALYSIS {
 void HybridMutex::assertHeldImpl() __TA_NO_THREAD_SAFETY_ANALYSIS {}
 
 u64 getMonotonicTime() { return _zx_clock_get_monotonic(); }
+u64 getMonotonicTimeFast() { return _zx_clock_get_monotonic(); }
 
 u32 getNumberOfCPUs() { return _zx_system_get_num_cpus(); }
 

diff  --git a/compiler-rt/lib/scudo/standalone/linux.cpp b/compiler-rt/lib/scudo/standalone/linux.cpp
index 33757e292f25b..e285d8a3d2d23 100644
--- a/compiler-rt/lib/scudo/standalone/linux.cpp
+++ b/compiler-rt/lib/scudo/standalone/linux.cpp
@@ -140,6 +140,17 @@ u64 getMonotonicTime() {
          static_cast<u64>(TS.tv_nsec);
 }
 
+u64 getMonotonicTimeFast() {
+#if defined(CLOCK_MONOTONIC_COARSE)
+  timespec TS;
+  clock_gettime(CLOCK_MONOTONIC_COARSE, &TS);
+  return static_cast<u64>(TS.tv_sec) * (1000ULL * 1000 * 1000) +
+         static_cast<u64>(TS.tv_nsec);
+#else
+  return getMonotonicTime();
+#endif
+}
+
 u32 getNumberOfCPUs() {
   cpu_set_t CPUs;
   // sched_getaffinity can fail for a variety of legitimate reasons (lack of

diff  --git a/compiler-rt/lib/scudo/standalone/primary32.h b/compiler-rt/lib/scudo/standalone/primary32.h
index 5d157f0277ac7..5d3bc658f6e89 100644
--- a/compiler-rt/lib/scudo/standalone/primary32.h
+++ b/compiler-rt/lib/scudo/standalone/primary32.h
@@ -73,7 +73,7 @@ template <typename Config> class SizeClassAllocator32 {
     DCHECK(isAligned(reinterpret_cast<uptr>(this), alignof(ThisT)));
     PossibleRegions.init();
     u32 Seed;
-    const u64 Time = getMonotonicTime();
+    const u64 Time = getMonotonicTimeFast();
     if (!getRandom(reinterpret_cast<void *>(&Seed), sizeof(Seed)))
       Seed = static_cast<u32>(
           Time ^ (reinterpret_cast<uptr>(SizeClassInfoArray) >> 6));
@@ -758,7 +758,7 @@ template <typename Config> class SizeClassAllocator32 {
         return 0;
       if (Sci->ReleaseInfo.LastReleaseAtNs +
               static_cast<u64>(IntervalMs) * 1000000 >
-          getMonotonicTime()) {
+          getMonotonicTimeFast()) {
         return 0; // Memory was returned recently.
       }
     }
@@ -850,7 +850,7 @@ template <typename Config> class SizeClassAllocator32 {
       Sci->ReleaseInfo.LastReleasedBytes = Recorder.getReleasedBytes();
       TotalReleasedBytes += Sci->ReleaseInfo.LastReleasedBytes;
     }
-    Sci->ReleaseInfo.LastReleaseAtNs = getMonotonicTime();
+    Sci->ReleaseInfo.LastReleaseAtNs = getMonotonicTimeFast();
 
     return TotalReleasedBytes;
   }

diff  --git a/compiler-rt/lib/scudo/standalone/primary64.h b/compiler-rt/lib/scudo/standalone/primary64.h
index 7868111bfc5c2..cbd1136889a5d 100644
--- a/compiler-rt/lib/scudo/standalone/primary64.h
+++ b/compiler-rt/lib/scudo/standalone/primary64.h
@@ -71,7 +71,7 @@ template <typename Config> class SizeClassAllocator64 {
         nullptr, PrimarySize, "scudo:primary_reserve", MAP_NOACCESS, &Data));
 
     u32 Seed;
-    const u64 Time = getMonotonicTime();
+    const u64 Time = getMonotonicTimeFast();
     if (!getRandom(reinterpret_cast<void *>(&Seed), sizeof(Seed)))
       Seed = static_cast<u32>(Time ^ (PrimaryBase >> 12));
     const uptr PageSize = getPageSizeCached();
@@ -796,7 +796,7 @@ template <typename Config> class SizeClassAllocator64 {
         return 0;
       if (Region->ReleaseInfo.LastReleaseAtNs +
               static_cast<u64>(IntervalMs) * 1000000 >
-          getMonotonicTime()) {
+          getMonotonicTimeFast()) {
         return 0; // Memory was returned recently.
       }
     }
@@ -995,7 +995,7 @@ template <typename Config> class SizeClassAllocator64 {
       Region->ReleaseInfo.RangesReleased += Recorder.getReleasedRangesCount();
       Region->ReleaseInfo.LastReleasedBytes = Recorder.getReleasedBytes();
     }
-    Region->ReleaseInfo.LastReleaseAtNs = getMonotonicTime();
+    Region->ReleaseInfo.LastReleaseAtNs = getMonotonicTimeFast();
 
     // Merge GroupToRelease back to the Region::FreeList. Note that both
     // `Region->FreeList` and `GroupToRelease` are sorted.

diff  --git a/compiler-rt/lib/scudo/standalone/trusty.cpp b/compiler-rt/lib/scudo/standalone/trusty.cpp
index 592514d4c3a6c..c08a4e6f43319 100644
--- a/compiler-rt/lib/scudo/standalone/trusty.cpp
+++ b/compiler-rt/lib/scudo/standalone/trusty.cpp
@@ -85,6 +85,17 @@ u64 getMonotonicTime() {
          static_cast<u64>(TS.tv_nsec);
 }
 
+u64 getMonotonicTimeFast() {
+#if defined(CLOCK_MONOTONIC_COARSE)
+  timespec TS;
+  clock_gettime(CLOCK_MONOTONIC_COARSE, &TS);
+  return static_cast<u64>(TS.tv_sec) * (1000ULL * 1000 * 1000) +
+         static_cast<u64>(TS.tv_nsec);
+#else
+  return getMonotonicTime();
+#endif
+}
+
 u32 getNumberOfCPUs() { return 0; }
 
 u32 getThreadID() { return 0; }