O_DIRECT
A file open flag provided by Linux that bypasses the kernel page cache and transfers data directly from disk to user-space buffers, giving programs full control over memory usage and avoiding performance thrashing caused by contention over the page cache.
Timeline (last 90 days)
cuFile requires file descriptors to be opened with O_DIRECT, and buffers must be registered (cuFileBufRegister) to enable the direct path.
The engine uses O_DIRECT and pinned memory for streaming reads of expert weights, with each expert rewritten as a 3,096,576-byte block (exactly 756 4KiB pages) to meet alignment requirements.
O_DIRECT is a Linux file open flag that bypasses the page cache and transfers data directly from disk to user-space buffers, letting a program fully control memory usage and avoid double-copy overhead.
Janas uses O_DIRECT to read expert weights on demand and tracks hot experts to keep them in an in-memory cache, thereby avoiding system-level page-fault storms.
Using O_DIRECT direct I/O bypasses the operating system's page cache, forgoing the caching acceleration that the page cache provides.
All Facts (5)
cuFile requires file descriptors to be opened with O_DIRECT, and buffers must be registered (cuFileBufRegister) to enable the direct path.
50%UnverifiedThe engine uses O_DIRECT and pinned memory for streaming reads of expert weights, with each expert rewritten as a 3,096,576-byte block (exactly 756 4KiB pages) to meet alignment requirements.
50%UnverifiedO_DIRECT is a Linux file open flag that bypasses the page cache and transfers data directly from disk to user-space buffers, letting a program fully control memory usage and avoid double-copy overhead.
50%UnverifiedJanas uses O_DIRECT to read expert weights on demand and tracks hot experts to keep them in an in-memory cache, thereby avoiding system-level page-fault storms.
50%UnverifiedUsing O_DIRECT direct I/O bypasses the operating system's page cache, forgoing the caching acceleration that the page cache provides.
50%