Author: glebius Date: Mon Dec 22 08:59:44 2014 New Revision: 276054 URL: https://svnweb.freebsd.org/changeset/base/276054
Log: Document flags of vm_page allocation functions. Reviewed by: alc Modified: head/sys/vm/vm_page.h Modified: head/sys/vm/vm_page.h ============================================================================== --- head/sys/vm/vm_page.h Mon Dec 22 04:54:57 2014 (r276053) +++ head/sys/vm/vm_page.h Mon Dec 22 08:59:44 2014 (r276054) @@ -376,22 +376,35 @@ extern long first_page; /* first physi vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa); -/* page allocation classes: */ +/* + * Page allocation parameters for vm_page for the functions + * vm_page_alloc(), vm_page_grab(), vm_page_alloc_contig() and + * vm_page_alloc_freelist(). Some functions support only a subset + * of the flags, and ignore others, see the flags legend. + * + * Bits 0 - 1 define class. + * Bits 2 - 15 dedicated for flags. + * Legend: + * (a) - vm_page_alloc() supports the flag. + * (c) - vm_page_alloc_contig() supports the flag. + * (f) - vm_page_alloc_freelist() supports the flag. + * (g) - vm_page_grab() supports the flag. + * Bits above 15 define the count of additional pages that the caller + * intends to allocate. + */ #define VM_ALLOC_NORMAL 0 #define VM_ALLOC_INTERRUPT 1 #define VM_ALLOC_SYSTEM 2 #define VM_ALLOC_CLASS_MASK 3 -/* page allocation flags: */ -#define VM_ALLOC_WIRED 0x0020 /* non pageable */ -#define VM_ALLOC_ZERO 0x0040 /* Try to obtain a zeroed page */ -#define VM_ALLOC_NOOBJ 0x0100 /* No associated object */ -#define VM_ALLOC_NOBUSY 0x0200 /* Do not busy the page */ -#define VM_ALLOC_IFCACHED 0x0400 /* Fail if the page is not cached */ -#define VM_ALLOC_IFNOTCACHED 0x0800 /* Fail if the page is cached */ -#define VM_ALLOC_IGN_SBUSY 0x1000 /* vm_page_grab() only */ -#define VM_ALLOC_NODUMP 0x2000 /* don't include in dump */ -#define VM_ALLOC_SBUSY 0x4000 /* Shared busy the page */ - +#define VM_ALLOC_WIRED 0x0020 /* (acfg) Allocate non pageable page */ +#define VM_ALLOC_ZERO 0x0040 /* (acfg) Try to obtain a zeroed page */ +#define VM_ALLOC_NOOBJ 0x0100 /* (acg) No associated object */ +#define VM_ALLOC_NOBUSY 0x0200 /* (acg) Do not busy the page */ +#define VM_ALLOC_IFCACHED 0x0400 /* (ag) Fail if page is not cached */ +#define VM_ALLOC_IFNOTCACHED 0x0800 /* (ag) Fail if page is cached */ +#define VM_ALLOC_IGN_SBUSY 0x1000 /* (g) Ignore shared busy flag */ +#define VM_ALLOC_NODUMP 0x2000 /* (ag) don't include in dump */ +#define VM_ALLOC_SBUSY 0x4000 /* (acg) Shared busy the page */ #define VM_ALLOC_COUNT_SHIFT 16 #define VM_ALLOC_COUNT(count) ((count) << VM_ALLOC_COUNT_SHIFT) _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
