[scudo] Tuning changes based on feedback from current use

Summary:
This tunes several of the default parameters used within the allocator:
- disable the deallocation type mismatch on Android by default; this
  was causing too many issues with third party libraries;
- change the default `SizeClassMap` to `Dense`, it caches less entries
  and is way more memory efficient overall;
- relax the timing of the RSS checks, 10 times per second was too much,
  lower it to 4 times (every 250ms), and update the test so that it
  passes with the new default.

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: srhines, delcypher, #sanitizers, llvm-commits

Differential Revision: https://reviews.llvm.org/D57116

llvm-svn: 352057

4 files changed, 18 insertions, 16 deletions

diff --git a/compiler-rt/lib/scudo/scudo_allocator.cpp b/compiler-rt/lib/scudo/scudo_allocator.cpp
index 4421667261b..172975eb90c 100644
--- a/compiler-rt/lib/scudo/scudo_allocator.cpp
+++ b/compiler-rt/lib/scudo/scudo_allocator.cpp
@@ -587,11 +587,11 @@ NOINLINE void Allocator::performSanityChecks() {
 }
 
 // Opportunistic RSS limit check. This will update the RSS limit status, if
-// it can, every 100ms, otherwise it will just return the current one.
+// it can, every 250ms, otherwise it will just return the current one.
 NOINLINE bool Allocator::isRssLimitExceeded() {
   u64 LastCheck = atomic_load_relaxed(&RssLastCheckedAtNS);
   const u64 CurrentCheck = MonotonicNanoTime();
-  if (LIKELY(CurrentCheck < LastCheck + (100ULL * 1000000ULL)))
+  if (LIKELY(CurrentCheck < LastCheck + (250ULL * 1000000ULL)))
     return atomic_load_relaxed(&RssLimitExceeded);
   if (!atomic_compare_exchange_weak(&RssLastCheckedAtNS, &LastCheck,
                                     CurrentCheck, memory_order_relaxed))
diff --git a/compiler-rt/lib/scudo/scudo_flags.inc b/compiler-rt/lib/scudo/scudo_flags.inc
index 6dffcbaa5ae..c124738c1f3 100644
--- a/compiler-rt/lib/scudo/scudo_flags.inc
+++ b/compiler-rt/lib/scudo/scudo_flags.inc
@@ -36,7 +36,9 @@ SCUDO_FLAG(int, QuarantineChunksUpToSize, -1,
           "Size in bytes up to which chunks will be quarantined (if lower than"
           "or equal to). Defaults to 256 (32-bit) or 2048 (64-bit)")
 
-SCUDO_FLAG(bool, DeallocationTypeMismatch, true,
+// Disable the deallocation type check by default on Android, it causes too many
+// issues with third party libraries.
+SCUDO_FLAG(bool, DeallocationTypeMismatch, !SANITIZER_ANDROID,
           "Report errors on malloc/delete, new/free, new/delete[], etc.")
 
 SCUDO_FLAG(bool, DeleteSizeMismatch, true,
diff --git a/compiler-rt/lib/scudo/scudo_platform.h b/compiler-rt/lib/scudo/scudo_platform.h
index d6e2001f3f8..07d4b70fc8e 100644
--- a/compiler-rt/lib/scudo/scudo_platform.h
+++ b/compiler-rt/lib/scudo/scudo_platform.h
@@ -79,7 +79,7 @@ const uptr RegionSizeLog = SANITIZER_ANDROID ? 19 : 20;
 #endif  // SANITIZER_CAN_USE_ALLOCATOR64
 
 #if !defined(SCUDO_SIZE_CLASS_MAP)
-# define SCUDO_SIZE_CLASS_MAP Default
+# define SCUDO_SIZE_CLASS_MAP Dense
 #endif
 
 #define SIZE_CLASS_MAP_TYPE SIZE_CLASS_MAP_TYPE_(SCUDO_SIZE_CLASS_MAP)
diff --git a/compiler-rt/test/scudo/rss.c b/compiler-rt/test/scudo/rss.c
index 4376290ad0c..f98bf9536ea 100644
--- a/compiler-rt/test/scudo/rss.c
+++ b/compiler-rt/test/scudo/rss.c
@@ -1,15 +1,15 @@
 // RUN: %clang_scudo %s -o %t
 // RUN:                                                                                                  %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-nolimit
-// RUN: %env_scudo_opts="soft_rss_limit_mb=256"                                                          %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-nolimit
-// RUN: %env_scudo_opts="hard_rss_limit_mb=256"                                                          %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-nolimit
-// RUN: %env_scudo_opts="soft_rss_limit_mb=64:allocator_may_return_null=0"                           not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-softlimit
-// RUN: %env_scudo_opts="soft_rss_limit_mb=64:allocator_may_return_null=1"                               %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-softlimit-returnnull
-// RUN: %env_scudo_opts="soft_rss_limit_mb=64:allocator_may_return_null=0:can_use_proc_maps_statm=0" not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-softlimit
-// RUN: %env_scudo_opts="soft_rss_limit_mb=64:allocator_may_return_null=1:can_use_proc_maps_statm=0"     %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-softlimit-returnnull
-// RUN: %env_scudo_opts="hard_rss_limit_mb=64:allocator_may_return_null=0"                           not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-hardlimit
-// RUN: %env_scudo_opts="hard_rss_limit_mb=64:allocator_may_return_null=1"                           not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-hardlimit
-// RUN: %env_scudo_opts="hard_rss_limit_mb=64:allocator_may_return_null=0:can_use_proc_maps_statm=0" not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-hardlimit
-// RUN: %env_scudo_opts="hard_rss_limit_mb=64:allocator_may_return_null=1:can_use_proc_maps_statm=0" not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-hardlimit
+// RUN: %env_scudo_opts="soft_rss_limit_mb=128"                                                          %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-nolimit
+// RUN: %env_scudo_opts="hard_rss_limit_mb=128"                                                          %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-nolimit
+// RUN: %env_scudo_opts="soft_rss_limit_mb=32:allocator_may_return_null=0"                           not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-softlimit
+// RUN: %env_scudo_opts="soft_rss_limit_mb=32:allocator_may_return_null=1"                               %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-softlimit-returnnull
+// RUN: %env_scudo_opts="soft_rss_limit_mb=32:allocator_may_return_null=0:can_use_proc_maps_statm=0" not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-softlimit
+// RUN: %env_scudo_opts="soft_rss_limit_mb=32:allocator_may_return_null=1:can_use_proc_maps_statm=0"     %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-softlimit-returnnull
+// RUN: %env_scudo_opts="hard_rss_limit_mb=32:allocator_may_return_null=0"                           not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-hardlimit
+// RUN: %env_scudo_opts="hard_rss_limit_mb=32:allocator_may_return_null=1"                           not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-hardlimit
+// RUN: %env_scudo_opts="hard_rss_limit_mb=32:allocator_may_return_null=0:can_use_proc_maps_statm=0" not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-hardlimit
+// RUN: %env_scudo_opts="hard_rss_limit_mb=32:allocator_may_return_null=1:can_use_proc_maps_statm=0" not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-hardlimit
 
 // Tests that the soft and hard RSS limits work as intended. Without limit or
 // with a high limit, the test should pass without any malloc returning NULL or
@@ -22,7 +22,7 @@
 #include <string.h>
 #include <unistd.h>
 
-static const size_t kNumAllocs = 128;
+static const size_t kNumAllocs = 64;
 static const size_t kAllocSize = 1 << 20;  // 1MB.
 
 static void *allocs[kNumAllocs];
@@ -31,7 +31,7 @@ int main(int argc, char *argv[]) {
   int returned_null = 0;
   for (int i = 0; i < kNumAllocs; i++) {
     if ((i & 0xf) == 0)
-      usleep(50000);
+      usleep(100000);
     allocs[i] = malloc(kAllocSize);
     if (allocs[i])
       memset(allocs[i], 0xff, kAllocSize);  // Dirty the pages.