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Kernel: Suppress logging during kmalloc heap expansion

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The system is extremely sensitive to heap allocations during heap
expansion. This was causing frequent OOM panics under various loads.

Work around the issue for now by putting the logging behind
KMALLOC_DEBUG. Ideally dmesgln() & friends would not reqiure any
heap allocations, but we're not there right now.

Fixes #5724.
This commit is contained in:
Andreas Kling 2021-03-11 15:26:02 +01:00
parent eb1ca965c7
commit b1e0e2ad4a
2 changed files with 30 additions and 9 deletions
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4
Kernel/Debug.h.in
View file

@ -146,6 +146,10 @@
#cmakedefine01 KEYBOARD_DEBUG #cmakedefine01 KEYBOARD_DEBUG
#endif #endif
#ifndef KMALLOC_DEBUG
#cmakedefine01 KMALLOC_DEBUG
#endif
#ifndef LOCAL_SOCKET_DEBUG #ifndef LOCAL_SOCKET_DEBUG
#cmakedefine01 LOCAL_SOCKET_DEBUG #cmakedefine01 LOCAL_SOCKET_DEBUG
#endif #endif

35
Kernel/Heap/kmalloc.cpp
View file

@ -1,5 +1,5 @@
/* /*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org> * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
* All rights reserved. * All rights reserved.
* *
* Redistribution and use in source and binary forms, with or without * Redistribution and use in source and binary forms, with or without
@ -33,6 +33,7 @@
#include <AK/NonnullOwnPtrVector.h> #include <AK/NonnullOwnPtrVector.h>
#include <AK/Types.h> #include <AK/Types.h>
#include <Kernel/Arch/i386/CPU.h> #include <Kernel/Arch/i386/CPU.h>
#include <Kernel/Debug.h>
#include <Kernel/Heap/Heap.h> #include <Kernel/Heap/Heap.h>
#include <Kernel/Heap/kmalloc.h> #include <Kernel/Heap/kmalloc.h>
#include <Kernel/KSyms.h> #include <Kernel/KSyms.h>
@ -64,7 +65,9 @@ struct KmallocGlobalHeap {
bool add_memory(size_t allocation_request) bool add_memory(size_t allocation_request)
{ {
if (!MemoryManager::is_initialized()) { if (!MemoryManager::is_initialized()) {
dmesgln("kmalloc: Cannot expand heap before MM is initialized!"); if constexpr (KMALLOC_DEBUG) {
dmesgln("kmalloc: Cannot expand heap before MM is initialized!");
}
return false; return false;
} }
VERIFY(!m_adding); VERIFY(!m_adding);
@ -78,13 +81,17 @@ struct KmallocGlobalHeap {
// Be careful to not log too much here. We don't want to trigger // Be careful to not log too much here. We don't want to trigger
// any further calls to kmalloc(). We're already out of memory // any further calls to kmalloc(). We're already out of memory
// and don't have any backup memory, either! // and don't have any backup memory, either!
dmesgln("kmalloc: Cannot expand heap: no backup memory"); if constexpr (KMALLOC_DEBUG) {
dmesgln("kmalloc: Cannot expand heap: no backup memory");
}
return false; return false;
} }
// At this point we should have at least enough memory from the // At this point we should have at least enough memory from the
// backup region to be able to log properly // backup region to be able to log properly
dmesgln("kmalloc: Adding memory to heap at {}, bytes: {}", region->vaddr(), region->size()); if constexpr (KMALLOC_DEBUG) {
dmesgln("kmalloc: Adding memory to heap at {}, bytes: {}", region->vaddr(), region->size());
}
auto& subheap = m_global_heap.m_heap.add_subheap(region->vaddr().as_ptr(), region->size()); auto& subheap = m_global_heap.m_heap.add_subheap(region->vaddr().as_ptr(), region->size());
m_global_heap.m_subheap_memory.append(region.release_nonnull()); m_global_heap.m_subheap_memory.append(region.release_nonnull());
@ -131,10 +138,14 @@ struct KmallocGlobalHeap {
if (m_global_heap.m_subheap_memory[i].vaddr().as_ptr() == memory) { if (m_global_heap.m_subheap_memory[i].vaddr().as_ptr() == memory) {
auto region = m_global_heap.m_subheap_memory.take(i); auto region = m_global_heap.m_subheap_memory.take(i);
if (!m_global_heap.m_backup_memory) { if (!m_global_heap.m_backup_memory) {
dmesgln("kmalloc: Using removed memory as backup: {}, bytes: {}", region->vaddr(), region->size()); if constexpr (KMALLOC_DEBUG) {
dmesgln("kmalloc: Using removed memory as backup: {}, bytes: {}", region->vaddr(), region->size());
}
m_global_heap.m_backup_memory = move(region); m_global_heap.m_backup_memory = move(region);
} else { } else {
dmesgln("kmalloc: Queue removing memory from heap at {}, bytes: {}", region->vaddr(), region->size()); if constexpr (KMALLOC_DEBUG) {
dmesgln("kmalloc: Queue removing memory from heap at {}, bytes: {}", region->vaddr(), region->size());
}
Processor::deferred_call_queue([this, region = move(region)]() mutable { Processor::deferred_call_queue([this, region = move(region)]() mutable {
// We need to defer freeing the region to prevent a potential // We need to defer freeing the region to prevent a potential
// deadlock since we are still holding the kmalloc lock // deadlock since we are still holding the kmalloc lock
@ -144,10 +155,14 @@ struct KmallocGlobalHeap {
// new backup. // new backup.
ScopedSpinLock lock(s_lock); ScopedSpinLock lock(s_lock);
if (!m_global_heap.m_backup_memory) { if (!m_global_heap.m_backup_memory) {
dmesgln("kmalloc: Queued memory region at {}, bytes: {} will be used as new backup", region->vaddr(), region->size()); if constexpr (KMALLOC_DEBUG) {
dmesgln("kmalloc: Queued memory region at {}, bytes: {} will be used as new backup", region->vaddr(), region->size());
}
m_global_heap.m_backup_memory = move(region); m_global_heap.m_backup_memory = move(region);
} else { } else {
dmesgln("kmalloc: Queued memory region at {}, bytes: {} will be freed now", region->vaddr(), region->size()); if constexpr (KMALLOC_DEBUG) {
dmesgln("kmalloc: Queued memory region at {}, bytes: {} will be freed now", region->vaddr(), region->size());
}
} }
}); });
} }
@ -155,7 +170,9 @@ struct KmallocGlobalHeap {
} }
} }
dmesgln("kmalloc: Cannot remove memory from heap: {}", VirtualAddress(memory)); if constexpr (KMALLOC_DEBUG) {
dmesgln("kmalloc: Cannot remove memory from heap: {}", VirtualAddress(memory));
}
return false; return false;
} }
}; };