Suspiciously intersecting memory ranges

[kvark]

Seeing this beauty:

general.rs(613) 		Size 6144, ready BitSet { mask: 1, groups: 1 }
general.rs(615) 			(0, Chunk { flavor: General(GeneralBlock { block_index: 0, chunk_index: 0, count: 1, memory: Memory { raw: Memory { raw: 0x7e000000007e }, size: 805306368, properties: CPU_VISIBLE | COHERENT, non_coherent_atom_size: None }, ptr: Some(0x7f0d3c000000), range: 0..49152 }), blocks: 192 })
general.rs(613) 		Size 49152, ready BitSet { mask: 1, groups: 1 }
general.rs(615) 			(0, Chunk { flavor: General(GeneralBlock { block_index: 0, chunk_index: 0, count: 4, memory: Memory { raw: Memory { raw: 0x7e000000007e }, size: 805306368, properties: CPU_VISIBLE | COHERENT, non_coherent_atom_size: None }, ptr: Some(0x7f0d3c000000), range: 0..393216 }), blocks: 254 })
general.rs(613) 		Size 393216, ready BitSet { mask: 1, groups: 1 }
general.rs(615) 			(0, Chunk { flavor: General(GeneralBlock { block_index: 0, chunk_index: 0, count: 4, memory: Memory { raw: Memory { raw: 0x7e000000007e }, size: 805306368, properties: CPU_VISIBLE | COHERENT, non_coherent_atom_size: None }, ptr: Some(0x7f0d3c000000), range: 0..3145728 }), blocks: 240 })
general.rs(613) 		Size 98304, ready BitSet { mask: 1, groups: 1 }
general.rs(615) 			(0, Chunk { flavor: General(GeneralBlock { block_index: 0, chunk_index: 0, count: 4, memory: Memory { raw: Memory { raw: 0x7e000000007e }, size: 805306368, properties: CPU_VISIBLE | COHERENT, non_coherent_atom_size: None }, ptr: Some(0x7f0d3c000000), range: 0..786432 }), blocks: 240 })
general.rs(613) 		Size 786432, ready BitSet { mask: 1, groups: 1 }
general.rs(615) 			(0, Chunk { flavor: General(GeneralBlock { block_index: 0, chunk_index: 0, count: 4, memory: Memory { raw: Memory { raw: 0x7e000000007e }, size: 805306368, properties: CPU_VISIBLE | COHERENT, non_coherent_atom_size: None }, ptr: Some(0x7f0d3c000000), range: 0..6291456 }), blocks: 240 })
general.rs(613) 		Size 196608, ready BitSet { mask: 1, groups: 1 }
general.rs(615) 			(0, Chunk { flavor: General(GeneralBlock { block_index: 0, chunk_index: 0, count: 4, memory: Memory { raw: Memory { raw: 0x7e000000007e }, size: 805306368, properties: CPU_VISIBLE | COHERENT, non_coherent_atom_size: None }, ptr: Some(0x7f0d3c000000), range: 0..1572864 }), blocks: 240 })
general.rs(613) 		Size 1572864, ready BitSet { mask: 1, groups: 1 }
general.rs(615) 			(0, Chunk { flavor: General(GeneralBlock { block_index: 0, chunk_index: 0, count: 4, memory: Memory { raw: Memory { raw: 0x7e000000007e }, size: 805306368, properties: CPU_VISIBLE | COHERENT, non_coherent_atom_size: None }, ptr: Some(0x7f0d3c000000), range: 0..12582912 }), blocks: 240 })
general.rs(613) 		Size 3145728, ready BitSet { mask: 1, groups: 1 }
general.rs(615) 			(0, Chunk { flavor: General(GeneralBlock { block_index: 0, chunk_index: 0, count: 4, memory: Memory { raw: Memory { raw: 0x7e000000007e }, size: 805306368, properties: CPU_VISIBLE | COHERENT, non_coherent_atom_size: None }, ptr: Some(0x7f0d3c000000), range: 0..25165824 }), blocks: 240 })
general.rs(613) 		Size 6291456, ready BitSet { mask: 1, groups: 1 }
general.rs(615) 			(0, Chunk { flavor: General(GeneralBlock { block_index: 0, chunk_index: 0, count: 4, memory: Memory { raw: Memory { raw: 0x7e000000007e }, size: 805306368, properties: CPU_VISIBLE | COHERENT, non_coherent_atom_size: None }, ptr: Some(0x7f0d3c000000), range: 0..50331648 }), blocks: 240 })
general.rs(613) 		Size 12582912, ready BitSet { mask: 1, groups: 1 }
general.rs(615) 			(0, Chunk { flavor: General(GeneralBlock { block_index: 0, chunk_index: 0, count: 4, memory: Memory { raw: Memory { raw: 0x7e000000007e }, size: 805306368, properties: CPU_VISIBLE | COHERENT, non_coherent_atom_size: None }, ptr: Some(0x7f0d3c000000), range: 0..100663296 }), blocks: 240 })
general.rs(613) 		Size 25165824, ready BitSet { mask: 1, groups: 1 }
general.rs(615) 			(0, Chunk { flavor: General(GeneralBlock { block_index: 0, chunk_index: 0, count: 4, memory: Memory { raw: Memory { raw: 0x7e000000007e }, size: 805306368, properties: CPU_VISIBLE | COHERENT, non_coherent_atom_size: None }, ptr: Some(0x7f0d3c000000), range: 0..201326592 }), blocks: 240 })
general.rs(613) 		Size 50331648, ready BitSet { mask: 1, groups: 1 }
general.rs(615) 			(0, Chunk { flavor: General(GeneralBlock { block_index: 0, chunk_index: 0, count: 4, memory: Memory { raw: Memory { raw: 0x7e000000007e }, size: 805306368, properties: CPU_VISIBLE | COHERENT, non_coherent_atom_size: None }, ptr: Some(0x7f0d3c000000), range: 0..402653184 }), blocks: 240 })
general.rs(613) 		Size 100663296, ready BitSet { mask: 1, groups: 1 }
general.rs(615) 			(0, Chunk { flavor: Dedicated { memory: Memory { raw: Memory { raw: 0x7e000000007e }, size: 805306368, properties: CPU_VISIBLE | COHERENT, non_coherent_atom_size: None }, ptr: Some(0x7f0d3c000000) }, blocks: 240 })

Need to figure out what's happening here. It could be that we only need small amount of memory but using the whole 800Mb chunk for some reason.

[kvark]

Turns out the intersection here is expected. The whole chain of allocation is spawned by a single small allocation. alloc_chunk tries to allocate MIN_BLOCKS_PER_CHUNK number of block sizes, doesn't find existing chunks of that 8x size, and requests a new block. This in turn leads to alloc_chunk again, and stops only when we reach the max_chunk_size...