Performance
Linux
What Happens to Your Data During a Linux read()? DMA, Page Cache, and CPU Copies
Follow a Linux buffered file read from storage to the page cache and user buffer. See what DMA handles, why the CPU …
Linux
False Sharing: Why Unrelated Writes Slow Each Other Down
Two threads updating separate variables can still slow each other down when both land on the same cache line. See why …
Linux
Why Locking a Mutex Usually Doesn't Need a System Call
An uncontended pthread_mutex_lock() usually runs a few user-space atomic instructions and never enters the kernel. …
Linux
sendfile() Promises Zero-Copy. Which Copies Does It Actually Remove?
sendfile() is marketed as zero-copy, but data still moves. See which two CPU copies the read()+write() path really …
Linux
Why Fewer Syscalls Don't Make io_uring Faster Than epoll
io_uring can reduce system calls without improving throughput or tail latency. Compare its completion model, batching, …