[scudo] Add utilization percentages for stats. #75101
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Refactor the percentage display in the secondary code. Re-use that to display a utilization percentage when displaying fragmentation data.
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compiler-rt
compiler-rt:scudo
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@llvm/pr-subscribers-compiler-rt-sanitizer Author: Christopher Ferris (cferris1000) ChangesRefactor the percentage display in the secondary code. Re-use that to display a utilization percentage when displaying fragmentation data. Full diff: https://github.com/llvm/llvm-project/pull/75101.diff 4 Files Affected:
diff --git a/compiler-rt/lib/scudo/standalone/common.h b/compiler-rt/lib/scudo/standalone/common.h
index 3581c946d1608..544a64ad3bf80 100644
--- a/compiler-rt/lib/scudo/standalone/common.h
+++ b/compiler-rt/lib/scudo/standalone/common.h
@@ -112,6 +112,21 @@ template <typename T> inline void shuffle(T *A, u32 N, u32 *RandState) {
*RandState = State;
}
+inline void computePercentage(uptr Numerator, uptr Denominator, uptr *Integral,
+ uptr *Fractional) {
+ constexpr uptr Digits = 100;
+ if (Denominator == 0) {
+ *Integral = 0;
+ *Fractional = 0;
+ return;
+ }
+
+ *Integral = Numerator * Digits / Denominator;
+ *Fractional =
+ (((Numerator * Digits) % Denominator) * Digits + Denominator / 2) /
+ Denominator;
+}
+
// Platform specific functions.
extern uptr PageSizeCached;
diff --git a/compiler-rt/lib/scudo/standalone/primary32.h b/compiler-rt/lib/scudo/standalone/primary32.h
index 8281e02ba164c..df1caae94dadd 100644
--- a/compiler-rt/lib/scudo/standalone/primary32.h
+++ b/compiler-rt/lib/scudo/standalone/primary32.h
@@ -931,10 +931,14 @@ template <typename Config> class SizeClassAllocator32 {
AllocatedPagesCount - Recorder.getReleasedPagesCount();
const uptr InUseBytes = InUsePages * PageSize;
+ uptr Integral;
+ uptr Fractional;
+ computePercentage(BlockSize * InUseBlocks, InUsePages * PageSize, &Integral,
+ &Fractional);
Str->append(" %02zu (%6zu): inuse/total blocks: %6zu/%6zu inuse/total "
- "pages: %6zu/%6zu inuse bytes: %6zuK\n",
+ "pages: %6zu/%6zu inuse bytes: %6zuK util: %2zu.%02zu%%\n",
ClassId, BlockSize, InUseBlocks, TotalBlocks, InUsePages,
- AllocatedPagesCount, InUseBytes >> 10);
+ AllocatedPagesCount, InUseBytes >> 10, Integral, Fractional);
}
NOINLINE uptr releaseToOSMaybe(SizeClassInfo *Sci, uptr ClassId,
diff --git a/compiler-rt/lib/scudo/standalone/primary64.h b/compiler-rt/lib/scudo/standalone/primary64.h
index d1929ff7212f4..d1f175cd15a11 100644
--- a/compiler-rt/lib/scudo/standalone/primary64.h
+++ b/compiler-rt/lib/scudo/standalone/primary64.h
@@ -1130,10 +1130,14 @@ template <typename Config> class SizeClassAllocator64 {
AllocatedPagesCount - Recorder.getReleasedPagesCount();
const uptr InUseBytes = InUsePages * PageSize;
+ uptr Integral;
+ uptr Fractional;
+ computePercentage(BlockSize * InUseBlocks, InUsePages * PageSize, &Integral,
+ &Fractional);
Str->append(" %02zu (%6zu): inuse/total blocks: %6zu/%6zu inuse/total "
- "pages: %6zu/%6zu inuse bytes: %6zuK\n",
+ "pages: %6zu/%6zu inuse bytes: %6zuK util: %2zu.%02zu%%\n",
ClassId, BlockSize, InUseBlocks, TotalBlocks, InUsePages,
- AllocatedPagesCount, InUseBytes >> 10);
+ AllocatedPagesCount, InUseBytes >> 10, Integral, Fractional);
}
NOINLINE uptr releaseToOSMaybe(RegionInfo *Region, uptr ClassId,
diff --git a/compiler-rt/lib/scudo/standalone/secondary.h b/compiler-rt/lib/scudo/standalone/secondary.h
index 8dc4c87fa7c6e..f52a4188bcf3a 100644
--- a/compiler-rt/lib/scudo/standalone/secondary.h
+++ b/compiler-rt/lib/scudo/standalone/secondary.h
@@ -155,20 +155,16 @@ template <typename Config> class MapAllocatorCache {
void getStats(ScopedString *Str) {
ScopedLock L(Mutex);
- u32 Integral = 0;
- u32 Fractional = 0;
- if (CallsToRetrieve != 0) {
- Integral = SuccessfulRetrieves * 100 / CallsToRetrieve;
- Fractional = (((SuccessfulRetrieves * 100) % CallsToRetrieve) * 100 +
- CallsToRetrieve / 2) /
- CallsToRetrieve;
- }
+ uptr Integral;
+ uptr Fractional;
+ computePercentage(SuccessfulRetrieves, CallsToRetrieve, &Integral,
+ &Fractional);
Str->append("Stats: MapAllocatorCache: EntriesCount: %d, "
"MaxEntriesCount: %u, MaxEntrySize: %zu\n",
EntriesCount, atomic_load_relaxed(&MaxEntriesCount),
atomic_load_relaxed(&MaxEntrySize));
Str->append("Stats: CacheRetrievalStats: SuccessRate: %u/%u "
- "(%u.%02u%%)\n",
+ "(%zu.%02zu%%)\n",
SuccessfulRetrieves, CallsToRetrieve, Integral, Fractional);
for (CachedBlock Entry : Entries) {
if (!Entry.isValid())
|
| inline void computePercentage(uptr Numerator, uptr Denominator, uptr *Integral, | ||
| uptr *Fractional) { | ||
| constexpr uptr Digits = 100; | ||
| if (Denominator == 0) { |
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I'm wondering if we want to assert a non-zero denominator. It seems to give the impression that 0/1 and 0/0 are the same here
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Another case I saw in real life, and I was wondering if I should say 100% when the denominator is 0. Since 0% feels like the wrong value, 100% also seems kind of wrong, but more correct than 0%. My other thought was doing NA, but that seems like it would be very difficult to implement without changing a lot of things.
I would think setting this to 100% seems the least bad and the most correct, but what do you think?
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You're right, I think 100% is better! (Given that NA is more complicated)
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Set to 100, and modified the two locations that use it to reserve enough space for that 100%.
| @@ -112,6 +112,21 @@ template <typename T> inline void shuffle(T *A, u32 N, u32 *RandState) { | |||
| *RandState = State; | |||
| } | |||
|
|
|||
| inline void computePercentage(uptr Numerator, uptr Denominator, uptr *Integral, | |||
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I was thinking if we want a Pair in Scudo but I didn't get a good use case to add it. This form works for me too. Will leave it to you to make the decision.
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Yeah, I was hoping I could use std::pair, but I think that would be a bad idea. And adding our own definition feels like a lot of work for a single case that's not necessary.
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Yeah, I agree with this
Refactor the percentage display in the secondary code. Re-use that to display a utilization percentage when displaying fragmentation data.