Worked on the geerlingguy/linux repository to deliver a targeted kernel-level performance optimization in the iomap buffer write path. Addressed write throughput and CPU efficiency by introducing a short-circuit using folio_test_uptodate(), which bypasses unnecessary calls to ifs_set_range_uptodate() when a folio is already marked uptodate. This approach reduced lock contention and instruction count in the common write path, directly benefiting IO-heavy workloads. The work was implemented in C and focused on file systems and kernel development, demonstrating a precise understanding of low-level performance bottlenecks and contributing a well-scoped feature that improves the efficiency of the iomap subsystem.