Intel Corporation

Sai Prashanth Muralidhara

Wei P Chen

Rajat Agarwal

Daniel W Liu

Nishant Singh

Sharada Venkateswaran

Alaa R Alameldeen

Vedaraman Geetha

Bahaa Fahim

Vivek Joy Kozhikkottu

Samuel D Strom

Jeffrey Baxter

A system includes a multilevel memory such as a two level memory (2LM), where a first level memory acts as a cache for the second level memory. A memory controller or cache controller can detect a cache miss in the first level memory for a request for data. Instead of automatically performing a swap, the controller can determine whether to perform a swap based on a swap policy assigned to a memory region associated with the address of the requested data.

Selective fill for logical control over hardware multilevel memory

A two-level main memory in which both volatile memory and persistent memory are exposed to the operating system in a flat manner and data movement and management is performed in cache line granularity is provided. The operating system can allocate pages in the two-level main memory randomly across the first level main memory and the second level main memory in a memory-type agnostic manner, or, in a more intelligent manner by allocating predicted hot pages in first level main memory and predicted cold pages in second level main memory. The cache line granularity movement is performed in a 'swap' manner, that is, a hot cache line in the second level main memory is swapped with a cold cache line in first level main memory because data is stored in either first level main memory or second level main memory not in both first level main memory and second level main memory.

Two-level main memory hierarchy management

A processor includes one or more cores having cache, a cache home agent (CHA), a near memory controller, to near memory, and a far memory controller, which is to: receive a first memory read operation from the CHA directed at a memory address; detect a miss for the first memory address at the near memory; issue a second memory read operation to the far memory controller to retrieve a cache line, having first data, from the memory address of far memory; receive the cache line from the far memory controller in response to the second memory read operation; and send the cache line to the CHA with a forced change to a directory state of the cache line at the CHA, the forced change to cause the CHA to snoop remote sockets to maintain data coherence for the cache line in an absence of directory state in the far memory.

Hybrid directory and snoopy-based coherency to reduce directory update overhead in two-level memory

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Portland, OR, United States of America

Sai Prashanth Muralidhara