Change Details

Change the usage of the pool field in vm_page structs. Currently, every page belongs to a pool, and the pool field identifies that pool. With this change: 1. Free memory blocks are only have valid pool fields when they are the first page in a block in a buddy queue. Otherwise, the value of pool is VM_NFREEPOOL. 2. Memory allocated in power-of-two sized blocks, by vm_phys_alloc_freelist_pages or vm_phys_alloc_pages, have only the first page of the block with a valid pool field; the others have VM_NFREEPOOL as their pool field. The function vm_phys_free_pages frees such blocks and restores the first page field to VM_NFREEPOOL. 3. Memory allocated as a number of pages, by vm_phys_alloc_npages or vm_phys_alloc_contig, has every page marked with the pool value. Such memory can be freed all at once with vm_phys_free_contig, or one page at a time with vm_phys_free_pages(m, 0). 4. A range of pages with all pool fields set to VM_NFREEPOOL can be freed with vm_phys_enqueue_contig, which passes the pool value as a parameter. The function vm_page_startup uses it to initialize the buddy queues, and vm_reserv_break uses it to return to the buddy queues unused pages from a broken reservation.

Change the usage of the pool field in vm_page structs. Currently, every page belongs to a pool, and the pool field identifies that pool. With this change: 1. Free memory blocks are only have valid pool fields when they are the first page in a block in a buddy queue. Otherwise, the value of pool is VM_NFREEPOOL. 2. Memory allocated in power-of-two sized blocks, by vm_phys_alloc_freelist_pages or vm_phys_alloc_pages, have only the first page of the block with a valid pool field; the others have VM_NFREEPOOL as their pool field. The function vm_phys_free_pages frees such blocks and restores the first page field to VM_NFREEPOOL. 3. Memory allocated as a number of pages by vm_phys_alloc_npages has no page marked with the pool value. The memory is freed by vm_phys_free_npages, and that caller provides the pool value as a parameter. Where the pool value is needed, in vm_page_free_toq, it has been supplied by the function that called uma_zalloc to allocate it from the pgcache. 4. Memory allocated as a number of pages, by vm_phys_alloc_contig, has every page marked with the pool value. Such memory can be freed all at once with vm_phys_free_contig, or one page at a time with vm_phys_free_pages(m, 0). 4. A range of pages with all pool fields set to VM_NFREEPOOL can be freed with vm_phys_enqueue_contig, which passes the pool value as a parameter. The function vm_page_startup uses it to initialize the buddy queues, and vm_reserv_break uses it to return to the buddy queues unused pages from a broken reservation.

Change the usage of the pool field in vm_page structs. Currently, every page belongs to a pool, and the pool field identifies that pool. With this change: 1. Free memory blocks are only have valid pool fields when they are the first page in a block in a buddy queue. Otherwise, the value of pool is VM_NFREEPOOL. 2. Memory allocated in power-of-two sized blocks, by vm_phys_alloc_freelist_pages or vm_phys_alloc_pages, have only the first page of the block with a valid pool field; the others have VM_NFREEPOOL as their pool field. The function vm_phys_free_pages frees such blocks and restores the first page field to VM_NFREEPOOL. 3. Memory allocated as a number of pages, by vm_phys_alloc_npages orhas vm_phys_alloc_contig, has everyno page marked with the pool value. SuchThe memory is freed by memory can be freed all at once with vm_phys_free_contignpages, or one pageand that caller provides the pool value as a parameter. Where the pool value is needed, in vm_page_free_toq, it has been supplied by the function that called uma_zalloc to allocate it from the pgcache. 4. Memory allocated as a number of pages, by vm_phys_alloc_contig, has every page marked with the pool value. Such memory can be freed all at once with vm_phys_free_contig, or one page at a time with vm_phys_free_pages(m, 0). 4. A range of pages with all pool fields set to VM_NFREEPOOL can be freed with vm_phys_enqueue_contig, which passes the pool value as a parameter. The function vm_page_startup uses it to initialize the buddy queues, and vm_reserv_break uses it to return to the buddy queues unused pages from a broken reservation.