Edata: Add a ranged bit.

We steal the dumpable bit, which we ended up not needing.
This commit is contained in:
David Goldblatt
2020-03-13 12:38:28 -07:00
committed by David Goldblatt
parent bd4fdf295e
commit 12eb888e54
6 changed files with 38 additions and 47 deletions

View File

@@ -68,7 +68,7 @@ struct edata_s {
* a: arena_ind
* b: slab
* c: committed
* d: dumpable
* r: ranged
* z: zeroed
* t: state
* i: szind
@@ -76,7 +76,7 @@ struct edata_s {
* s: bin_shard
* n: sn
*
* nnnnnnnn ... nnnnnnss ssssffff ffffffii iiiiiitt zdcbaaaa aaaaaaaa
* nnnnnnnn ... nnnnnnss ssssffff ffffffii iiiiiitt zrcbaaaa aaaaaaaa
*
* arena_ind: Arena from which this extent came, or all 1 bits if
* unassociated.
@@ -91,22 +91,10 @@ struct edata_s {
* as on a system that overcommits and satisfies physical
* memory needs on demand via soft page faults.
*
* dumpable: The dumpable flag indicates whether or not we've set the
* memory in question to be dumpable. Note that this
* interacts somewhat subtly with user-specified extent hooks,
* since we don't know if *they* are fiddling with
* dumpability (in which case, we don't want to undo whatever
* they're doing). To deal with this scenario, we:
* - Make dumpable false only for memory allocated with the
* default hooks.
* - Only allow memory to go from non-dumpable to dumpable,
* and only once.
* - Never make the OS call to allow dumping when the
* dumpable bit is already set.
* These three constraints mean that we will never
* accidentally dump user memory that the user meant to set
* nondumpable with their extent hooks.
*
* ranged: Whether or not this extent is currently owned by the range
* allocator. This may be false even if the extent originally
* came from a range allocator; this indicates its *current*
* owner, not its original owner.
*
* zeroed: The zeroed flag is used by extent recycling code to track
* whether memory is zero-filled.
@@ -148,12 +136,12 @@ struct edata_s {
#define EDATA_BITS_COMMITTED_SHIFT (EDATA_BITS_SLAB_WIDTH + EDATA_BITS_SLAB_SHIFT)
#define EDATA_BITS_COMMITTED_MASK MASK(EDATA_BITS_COMMITTED_WIDTH, EDATA_BITS_COMMITTED_SHIFT)
#define EDATA_BITS_DUMPABLE_WIDTH 1
#define EDATA_BITS_DUMPABLE_SHIFT (EDATA_BITS_COMMITTED_WIDTH + EDATA_BITS_COMMITTED_SHIFT)
#define EDATA_BITS_DUMPABLE_MASK MASK(EDATA_BITS_DUMPABLE_WIDTH, EDATA_BITS_DUMPABLE_SHIFT)
#define EDATA_BITS_RANGED_WIDTH 1
#define EDATA_BITS_RANGED_SHIFT (EDATA_BITS_COMMITTED_WIDTH + EDATA_BITS_COMMITTED_SHIFT)
#define EDATA_BITS_RANGED_MASK MASK(EDATA_BITS_RANGED_WIDTH, EDATA_BITS_RANGED_SHIFT)
#define EDATA_BITS_ZEROED_WIDTH 1
#define EDATA_BITS_ZEROED_SHIFT (EDATA_BITS_DUMPABLE_WIDTH + EDATA_BITS_DUMPABLE_SHIFT)
#define EDATA_BITS_ZEROED_SHIFT (EDATA_BITS_RANGED_WIDTH + EDATA_BITS_RANGED_SHIFT)
#define EDATA_BITS_ZEROED_MASK MASK(EDATA_BITS_ZEROED_WIDTH, EDATA_BITS_ZEROED_SHIFT)
#define EDATA_BITS_STATE_WIDTH 2
@@ -283,9 +271,9 @@ edata_committed_get(const edata_t *edata) {
}
static inline bool
edata_dumpable_get(const edata_t *edata) {
return (bool)((edata->e_bits & EDATA_BITS_DUMPABLE_MASK) >>
EDATA_BITS_DUMPABLE_SHIFT);
edata_ranged_get(const edata_t *edata) {
return (bool)((edata->e_bits & EDATA_BITS_RANGED_MASK) >>
EDATA_BITS_RANGED_SHIFT);
}
static inline bool
@@ -479,9 +467,9 @@ edata_committed_set(edata_t *edata, bool committed) {
}
static inline void
edata_dumpable_set(edata_t *edata, bool dumpable) {
edata->e_bits = (edata->e_bits & ~EDATA_BITS_DUMPABLE_MASK) |
((uint64_t)dumpable << EDATA_BITS_DUMPABLE_SHIFT);
edata_ranged_set(edata_t *edata, bool ranged) {
edata->e_bits = (edata->e_bits & ~EDATA_BITS_RANGED_MASK) |
((uint64_t)ranged << EDATA_BITS_RANGED_SHIFT);
}
static inline void
@@ -522,8 +510,9 @@ edata_is_head_set(edata_t *edata, bool is_head) {
static inline void
edata_init(edata_t *edata, unsigned arena_ind, void *addr, size_t size,
bool slab, szind_t szind, size_t sn, extent_state_t state, bool zeroed,
bool committed, bool dumpable, extent_head_state_t is_head) {
bool committed, bool ranged, extent_head_state_t is_head) {
assert(addr == PAGE_ADDR2BASE(addr) || !slab);
assert(ranged == false);
edata_arena_ind_set(edata, arena_ind);
edata_addr_set(edata, addr);
@@ -534,7 +523,7 @@ edata_init(edata_t *edata, unsigned arena_ind, void *addr, size_t size,
edata_state_set(edata, state);
edata_zeroed_set(edata, zeroed);
edata_committed_set(edata, committed);
edata_dumpable_set(edata, dumpable);
edata_ranged_set(edata, ranged);
ql_elm_new(edata, ql_link);
edata_is_head_set(edata, is_head == EXTENT_IS_HEAD);
if (config_prof) {
@@ -553,7 +542,7 @@ edata_binit(edata_t *edata, void *addr, size_t bsize, size_t sn) {
edata_state_set(edata, extent_state_active);
edata_zeroed_set(edata, true);
edata_committed_set(edata, true);
edata_dumpable_set(edata, true);
edata_ranged_set(edata, false);
}
static inline void