Tag
cache-coherence
- Aug 31, 2026 Spinlock Contention: Ticket Ordering and MCS Queues Why a test-and-set spinlock makes every waiter hammer one cache line, how a ticket lock restores first-come order, and why a queue of per-thread flags beats both. operating systems
- Aug 26, 2026 Read-Modify-Write Atomicity and the Ordering It Carries Why an atomic increment cannot be built from a load and a store, what compare-and-swap costs in coherence traffic, and how an atomic operation acts as a fence. computer architecture
- Aug 20, 2026 Attribute Caching and Close-to-Open Consistency Every stat over the network is a round trip, so clients cache attributes with short leases and validate them on reuse. The guarantee that emerges is not POSIX coherence but a weaker promise tied to open and close. filesystems
- Apr 17, 2026 Cache Coherence Is Per Location, Consistency Is Not Why a machine can agree perfectly on the order of writes to every individual address and still produce an execution with no single global ordering. computer architecture
- Mar 16, 2026 Coherence and the Modification Order of a Single Location The four coherence axioms, why per-location agreement is much weaker than a global order, and how IRIW separates the two. memory systems
- Oct 21, 2025 Acquire and Release Ordering: What a Lock Actually Guarantees About Memory How store buffers and compiler reordering let a consumer observe a published value before the data it points to, and how release and acquire operations restore the ordering without a full fence. operating systems
- Oct 3, 2025 Reader-Writer Locks and the Starvation They Invite How a shared-exclusive lock counts readers in one word, why an unbroken stream of readers can postpone a writer indefinitely, and which fairness schemes actually bound the wait. operating systems
- May 26, 2025 Delegations, Callback Channels, and Recall A server can hand a client authority over a file so the client stops asking, but it must be able to take that authority back. The mechanism is a lease with a reverse direction, and its hard part is the recall path. filesystems
- May 6, 2025 Atomic Read-Modify-Write and the Mutual Exclusion Problem Why a flag plus a check cannot keep two threads out of the same critical section, and what a single indivisible read-modify-write instruction changes about the problem. operating systems
- Apr 15, 2025 NUMA Placement and the Cost of Touching Another Socket's Memory How first-touch page placement decides which socket holds a page, what a remote access costs relative to a local one, and why thread pinning without memory placement leaves the cost in place. performance engineering
- Aug 13, 2024 MESI Transitions and the Traffic an Invalidation Generates What each coherence state permits, which transactions move a line between them, and why a false sharing pattern produces more bus traffic than the data it writes. memory systems
- Jan 30, 2023 Cache Line Transfer, False Sharing, and the Cost of Contention Why an atomic operation on an uncontended location is cheap and on a contended one is not, what coherence protocol traffic each attempt generates, and how padding and sharding change the shape of the cost. systems programming
- Feb 15, 2022 Node Distance and the Real Cost of a Remote Memory Access How a cache-coherent link turns an ordinary load into a transaction between two sockets, why distance values are ranks rather than nanoseconds, and which resource a remote access actually consumes. memory systems