diff options
| author | Ariane van der Steldt <ariane@cvs.openbsd.org> | 2009-08-13 20:40:14 +0000 |
|---|---|---|
| committer | Ariane van der Steldt <ariane@cvs.openbsd.org> | 2009-08-13 20:40:14 +0000 |
| commit | 3af80e8da068c73661588621f782e0f00ed85d4d (patch) | |
| tree | d980e45ecd628664ec1b231347950b2a0d2de1c6 /sys/uvm | |
| parent | f77e628497527ea3ad8398c64e07fe37e41d92e7 (diff) | |
Enable guard pages and slow recycling of kva.
Debugging aid, hiding in "option KVA_GUARDPAGES" in config.
Diffstat (limited to 'sys/uvm')
| -rw-r--r-- | sys/uvm/uvm_map.c | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/sys/uvm/uvm_map.c b/sys/uvm/uvm_map.c index e418e9bbeb6..938fb3edd16 100644 --- a/sys/uvm/uvm_map.c +++ b/sys/uvm/uvm_map.c @@ -1,4 +1,4 @@ -/* $OpenBSD: uvm_map.c,v 1.120 2009/08/06 15:28:14 oga Exp $ */ +/* $OpenBSD: uvm_map.c,v 1.121 2009/08/13 20:40:13 ariane Exp $ */ /* $NetBSD: uvm_map.c,v 1.86 2000/11/27 08:40:03 chs Exp $ */ /* @@ -724,6 +724,38 @@ uvm_map_p(struct vm_map *map, vaddr_t *startp, vsize_t size, map, *startp, size, flags); UVMHIST_LOG(maphist, " uobj/offset %p/%ld", uobj, (u_long)uoffset,0,0); +#ifdef KVA_GUARDPAGES + if (map == kernel_map) { + /* + * kva_guardstart is initialized to the start of the kernelmap + * and cycles through the kva space. + * This way we should have a long time between re-use of kva. + */ + static vaddr_t kva_guardstart = 0; + if (kva_guardstart == 0) { + kva_guardstart = vm_map_min(map); + printf("uvm_map: kva guard pages enabled: %p\n", + kva_guardstart); + } + size += PAGE_SIZE; /* Add guard page at the end. */ + /* + * Try to fully exhaust kva prior to wrap-around. + * (This may eat your ram!) + */ + if (VM_MAX_KERNEL_ADDRESS < (kva_guardstart + size)) { + static int wrap_counter = 0; + printf("uvm_map: kva guard page wrap-around %d\n", + ++wrap_counter); + kva_guardstart = vm_map_min(map); + } + *startp = kva_guardstart; + /* + * Prepare for next round. + */ + kva_guardstart += size; + } +#endif + uvm_tree_sanity(map, "map entry"); if ((map->flags & VM_MAP_INTRSAFE) == 0) @@ -1424,6 +1456,12 @@ uvm_unmap_p(vm_map_t map, vaddr_t start, vaddr_t end, struct proc *p) UVMHIST_LOG(maphist, " (map=%p, start=0x%lx, end=0x%lx)", map, start, end, 0); + +#ifdef KVA_GUARDPAGES + if (map == kernel_map) + end += PAGE_SIZE; /* Add guardpage. */ +#endif + /* * work now done by helper functions. wipe the pmap's and then * detach from the dead entries... |