This is the wildcard. In standard MM, "exclusive" often means:
Subject to cryptographic shredding (overwritten with random data) before being unlinked. Architectural Use Cases define labyrinth void allocpagegfpatomic exclusive
Can be mapped to multiple address spaces or shared memory pools. This is the wildcard
void *labyrinth_alloc_page_gfp_atomic_exclusive(gfp_t gfp, int order); void *labyrinth_alloc_page_gfp_atomic_exclusive(gfp_t gfp
: If a driver needs memory during an interrupt, consider pre-allocating the memory buffer during the driver's initialization phase using standard GFP_KERNEL flags, or utilize a mempool_t (Memory Pool). 4. Summary Table: Atomic vs. Standard Allocation GFP_ATOMIC (Exclusive Reserves) GFP_KERNEL (Standard) Can Sleep/Block? Context Allowed Interrupt, Spinlock, Process Process Context Only Memory Sources Emergency Reserves (Below Low Watermark) Standard Free Zones Behavior on Shortage Returns NULL immediately Swaps to disk, reclaims, blocks Reliability Lower (Fails under heavy fragmentation) Higher (Will fight to find memory)
Unlike user-space allocation functions like malloc() , which operate on bytes and manage a heap via a library (glibc), alloc_pages communicates directly with the buddy allocator. The buddy allocator manages physical memory blocks in powers of two (orders). When alloc_page is invoked:
by the calling thread or process. This often implies that the page is locked or marked so that no other part of the system can access or modify it until it is explicitly released. Full Feature Overview