https://bluuewhale.github.io/tags/cpu/Recent content in CPU on Bluue Whalehttps://bluuewhale.github.io/images/profile.jpghttps://bluuewhale.github.io/images/profile.jpgHugo -- 0.152.2en-usSat, 22 Aug 2026 22:21:36 +0900https://bluuewhale.github.io/posts/sparse-matrix-and-csr-en/Wed, 01 Apr 2026 16:23:49 +0900https://bluuewhale.github.io/posts/sparse-matrix-and-csr-en/How CSR (Compressed Sparse Row) represents a sparse matrix with just three arrays, values, column_indices, and row_pointers, and why it speeds up sparse matrix-vector multiplication and graph neighbor lookups.https://bluuewhale.github.io/posts/debugging-false-sharing-en/Fri, 12 Dec 2025 10:52:00 +0900https://bluuewhale.github.io/posts/debugging-false-sharing-en/How Netflix tripled a service's CPU capacity, got only a 25% throughput gain, and traced the gap back to false sharing using hardware performance counters.https://bluuewhale.github.io/posts/spinlock-vs-mutex-en/Fri, 12 Dec 2025 10:20:40 +0900https://bluuewhale.github.io/posts/spinlock-vs-mutex-en/Why a userspace spinlock spinning on CAS and a kernel-backed mutex going through futex end up suited to different workloads, explained through cache coherence.