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Kernel: Limit the number of in-flight packet buffers

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This fixes an OOM when hitting the VM with lots of UDP packets.

fixes #6907
This commit is contained in:
Gunnar Beutner 2021-05-06 20:22:57 +02:00 • committed by Andreas Kling
parent dd39bb7784
commit f999d5a91a
2 changed files with 11 additions and 0 deletions
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7
Kernel/Net/NetworkAdapter.cpp
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@ -160,6 +160,11 @@ void NetworkAdapter::did_receive(ReadonlyBytes payload)
Optional<KBuffer> buffer; Optional<KBuffer> buffer;
if (m_packet_queue_size == max_packet_buffers) {
// FIXME: Keep track of the number of dropped packets
return;
}
if (m_unused_packet_buffers.is_empty()) { if (m_unused_packet_buffers.is_empty()) {
buffer = KBuffer::copy(payload.data(), payload.size()); buffer = KBuffer::copy(payload.data(), payload.size());
} else { } else {
@ -174,6 +179,7 @@ void NetworkAdapter::did_receive(ReadonlyBytes payload)
} }
m_packet_queue.append({ buffer.value(), kgettimeofday() }); m_packet_queue.append({ buffer.value(), kgettimeofday() });
m_packet_queue_size++;
if (on_receive) if (on_receive)
on_receive(); on_receive();
@ -185,6 +191,7 @@ size_t NetworkAdapter::dequeue_packet(u8* buffer, size_t buffer_size, Time& pack
if (m_packet_queue.is_empty()) if (m_packet_queue.is_empty())
return 0; return 0;
auto packet_with_timestamp = m_packet_queue.take_first(); auto packet_with_timestamp = m_packet_queue.take_first();
m_packet_queue_size--;
packet_timestamp = packet_with_timestamp.timestamp; packet_timestamp = packet_with_timestamp.timestamp;
auto packet = move(packet_with_timestamp.packet); auto packet = move(packet_with_timestamp.packet);
size_t packet_size = packet.size(); size_t packet_size = packet.size();

4
Kernel/Net/NetworkAdapter.h
View file

@ -80,7 +80,11 @@ private:
Time timestamp; Time timestamp;
}; };
// FIXME: Make this configurable
static constexpr size_t max_packet_buffers = 1024;
SinglyLinkedList<PacketWithTimestamp> m_packet_queue; SinglyLinkedList<PacketWithTimestamp> m_packet_queue;
size_t m_packet_queue_size { 0 };
SinglyLinkedList<KBuffer> m_unused_packet_buffers; SinglyLinkedList<KBuffer> m_unused_packet_buffers;
size_t m_unused_packet_buffers_count { 0 }; size_t m_unused_packet_buffers_count { 0 };
String m_name; String m_name;