server-skynet-source-3rd-je.../include/jemalloc/internal/hpdata.h

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#ifndef JEMALLOC_INTERNAL_HPDATA_H
#define JEMALLOC_INTERNAL_HPDATA_H
#include "jemalloc/internal/fb.h"
#include "jemalloc/internal/ph.h"
#include "jemalloc/internal/ql.h"
#include "jemalloc/internal/typed_list.h"
/*
* The metadata representation we use for extents in hugepages. While the PAC
* uses the edata_t to represent both active and inactive extents, the HP only
* uses the edata_t for active ones; instead, inactive extent state is tracked
* within hpdata associated with the enclosing hugepage-sized, hugepage-aligned
* region of virtual address space.
*
* An hpdata need not be "truly" backed by a hugepage (which is not necessarily
* an observable property of any given region of address space). It's just
* hugepage-sized and hugepage-aligned; it's *potentially* huge.
*/
typedef struct hpdata_s hpdata_t;
struct hpdata_s {
/*
* We likewise follow the edata convention of mangling names and forcing
* the use of accessors -- this lets us add some consistency checks on
* access.
*/
/*
* The address of the hugepage in question. This can't be named h_addr,
* since that conflicts with a macro defined in Windows headers.
*/
void *h_address;
/* Its age (measured in psset operations). */
uint64_t h_age;
/* Whether or not we think the hugepage is mapped that way by the OS. */
bool h_huge;
/*
HPA: Track pending purges/hugifies in the psset. This finishes the refactoring of the HPA/psset interactions the past few commits have been building towards. Rather than the HPA removing and then reinserting hpdatas, it simply begins updates and ends them. These updates can set flags on the hpdata that prevent it from being returned for certain types of requests. For example, it can call hpdata_alloc_allowed_set(hpdata, false) during an update, at which point the given hpdata will no longer be returned for psset_pick_alloc requests. This has various of benefits: - It maintains stats correctness during purges and hugifies. - It allows simpler and more explicit concurrency control for the various special cases (e.g. allocations are disallowed during purge, but not during hugify). - It lets allocations and deallocations avoid disturbing the purging and hugification orderings. If an hpdata "loses its place" in one of the queues just do to an alloc / dalloc, it can result in pathological edge cases where very hot, very full hugepages never get hugified (and cold extents on the same hugepage as hot ones never get purged). The key benefit though is that tracking hpdatas to be purged / hugified in a principled way will let us do delayed purging and hugification. Eventually this will let us move these operations to background threads, but in the short term the benefit is that it will let us have global purging policies (e.g. purge when the entire arena has too many dirty pages, rather than any particular hugepage).
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* For some properties, we keep parallel sets of bools; h_foo_allowed
* and h_in_psset_foo_container. This is a decoupling mechanism to
* avoid bothering the hpa (which manages policies) from the psset
* (which is the mechanism used to enforce those policies). This allows
* all the container management logic to live in one place, without the
* HPA needing to know or care how that happens.
*/
HPA: Track pending purges/hugifies in the psset. This finishes the refactoring of the HPA/psset interactions the past few commits have been building towards. Rather than the HPA removing and then reinserting hpdatas, it simply begins updates and ends them. These updates can set flags on the hpdata that prevent it from being returned for certain types of requests. For example, it can call hpdata_alloc_allowed_set(hpdata, false) during an update, at which point the given hpdata will no longer be returned for psset_pick_alloc requests. This has various of benefits: - It maintains stats correctness during purges and hugifies. - It allows simpler and more explicit concurrency control for the various special cases (e.g. allocations are disallowed during purge, but not during hugify). - It lets allocations and deallocations avoid disturbing the purging and hugification orderings. If an hpdata "loses its place" in one of the queues just do to an alloc / dalloc, it can result in pathological edge cases where very hot, very full hugepages never get hugified (and cold extents on the same hugepage as hot ones never get purged). The key benefit though is that tracking hpdatas to be purged / hugified in a principled way will let us do delayed purging and hugification. Eventually this will let us move these operations to background threads, but in the short term the benefit is that it will let us have global purging policies (e.g. purge when the entire arena has too many dirty pages, rather than any particular hugepage).
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/*
* Whether or not the hpdata is allowed to be used to serve allocations,
* and whether or not the psset is currently tracking it as such.
*/
bool h_alloc_allowed;
bool h_in_psset_alloc_container;
/*
* The same, but with purging. There's no corresponding
* h_in_psset_purge_container, because the psset (currently) always
* removes hpdatas from their containers during updates (to implement
* LRU for purging).
*/
bool h_purge_allowed;
HPA: Track pending purges/hugifies in the psset. This finishes the refactoring of the HPA/psset interactions the past few commits have been building towards. Rather than the HPA removing and then reinserting hpdatas, it simply begins updates and ends them. These updates can set flags on the hpdata that prevent it from being returned for certain types of requests. For example, it can call hpdata_alloc_allowed_set(hpdata, false) during an update, at which point the given hpdata will no longer be returned for psset_pick_alloc requests. This has various of benefits: - It maintains stats correctness during purges and hugifies. - It allows simpler and more explicit concurrency control for the various special cases (e.g. allocations are disallowed during purge, but not during hugify). - It lets allocations and deallocations avoid disturbing the purging and hugification orderings. If an hpdata "loses its place" in one of the queues just do to an alloc / dalloc, it can result in pathological edge cases where very hot, very full hugepages never get hugified (and cold extents on the same hugepage as hot ones never get purged). The key benefit though is that tracking hpdatas to be purged / hugified in a principled way will let us do delayed purging and hugification. Eventually this will let us move these operations to background threads, but in the short term the benefit is that it will let us have global purging policies (e.g. purge when the entire arena has too many dirty pages, rather than any particular hugepage).
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/* And with hugifying. */
bool h_hugify_allowed;
bool h_in_psset_hugify_container;
/* Whether or not a purge or hugify is currently happening. */
bool h_mid_purge;
bool h_mid_hugify;
/*
* Whether or not the hpdata is being updated in the psset (i.e. if
* there has been a psset_update_begin call issued without a matching
* psset_update_end call). Eventually this will expand to other types
* of updates.
*/
bool h_updating;
/* Whether or not the hpdata is in a psset. */
bool h_in_psset;
union {
/* When nonempty (and also nonfull), used by the psset bins. */
phn(hpdata_t) ph_link;
/*
* When empty (or not corresponding to any hugepage), list
* linkage.
*/
ql_elm(hpdata_t) ql_link_empty;
};
HPA: Track pending purges/hugifies in the psset. This finishes the refactoring of the HPA/psset interactions the past few commits have been building towards. Rather than the HPA removing and then reinserting hpdatas, it simply begins updates and ends them. These updates can set flags on the hpdata that prevent it from being returned for certain types of requests. For example, it can call hpdata_alloc_allowed_set(hpdata, false) during an update, at which point the given hpdata will no longer be returned for psset_pick_alloc requests. This has various of benefits: - It maintains stats correctness during purges and hugifies. - It allows simpler and more explicit concurrency control for the various special cases (e.g. allocations are disallowed during purge, but not during hugify). - It lets allocations and deallocations avoid disturbing the purging and hugification orderings. If an hpdata "loses its place" in one of the queues just do to an alloc / dalloc, it can result in pathological edge cases where very hot, very full hugepages never get hugified (and cold extents on the same hugepage as hot ones never get purged). The key benefit though is that tracking hpdatas to be purged / hugified in a principled way will let us do delayed purging and hugification. Eventually this will let us move these operations to background threads, but in the short term the benefit is that it will let us have global purging policies (e.g. purge when the entire arena has too many dirty pages, rather than any particular hugepage).
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/*
* Linkage for the psset to track candidates for purging and hugifying.
*/
ql_elm(hpdata_t) ql_link_purge;
ql_elm(hpdata_t) ql_link_hugify;
/* The length of the largest contiguous sequence of inactive pages. */
size_t h_longest_free_range;
/* Number of active pages. */
size_t h_nactive;
/* A bitmap with bits set in the active pages. */
fb_group_t active_pages[FB_NGROUPS(HUGEPAGE_PAGES)];
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/*
* Number of dirty or active pages, and a bitmap tracking them. One
* way to think of this is as which pages are dirty from the OS's
* perspective.
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*/
size_t h_ntouched;
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/* The touched pages (using the same definition as above). */
fb_group_t touched_pages[FB_NGROUPS(HUGEPAGE_PAGES)];
};
TYPED_LIST(hpdata_empty_list, hpdata_t, ql_link_empty)
HPA: Track pending purges/hugifies in the psset. This finishes the refactoring of the HPA/psset interactions the past few commits have been building towards. Rather than the HPA removing and then reinserting hpdatas, it simply begins updates and ends them. These updates can set flags on the hpdata that prevent it from being returned for certain types of requests. For example, it can call hpdata_alloc_allowed_set(hpdata, false) during an update, at which point the given hpdata will no longer be returned for psset_pick_alloc requests. This has various of benefits: - It maintains stats correctness during purges and hugifies. - It allows simpler and more explicit concurrency control for the various special cases (e.g. allocations are disallowed during purge, but not during hugify). - It lets allocations and deallocations avoid disturbing the purging and hugification orderings. If an hpdata "loses its place" in one of the queues just do to an alloc / dalloc, it can result in pathological edge cases where very hot, very full hugepages never get hugified (and cold extents on the same hugepage as hot ones never get purged). The key benefit though is that tracking hpdatas to be purged / hugified in a principled way will let us do delayed purging and hugification. Eventually this will let us move these operations to background threads, but in the short term the benefit is that it will let us have global purging policies (e.g. purge when the entire arena has too many dirty pages, rather than any particular hugepage).
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TYPED_LIST(hpdata_purge_list, hpdata_t, ql_link_purge)
TYPED_LIST(hpdata_hugify_list, hpdata_t, ql_link_hugify)
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typedef ph(hpdata_t) hpdata_age_heap_t;
ph_proto(, hpdata_age_heap_, hpdata_age_heap_t, hpdata_t);
static inline void *
hpdata_addr_get(const hpdata_t *hpdata) {
return hpdata->h_address;
}
static inline void
hpdata_addr_set(hpdata_t *hpdata, void *addr) {
assert(HUGEPAGE_ADDR2BASE(addr) == addr);
hpdata->h_address = addr;
}
static inline uint64_t
hpdata_age_get(const hpdata_t *hpdata) {
return hpdata->h_age;
}
static inline void
hpdata_age_set(hpdata_t *hpdata, uint64_t age) {
hpdata->h_age = age;
}
static inline bool
hpdata_huge_get(const hpdata_t *hpdata) {
return hpdata->h_huge;
}
static inline bool
HPA: Track pending purges/hugifies in the psset. This finishes the refactoring of the HPA/psset interactions the past few commits have been building towards. Rather than the HPA removing and then reinserting hpdatas, it simply begins updates and ends them. These updates can set flags on the hpdata that prevent it from being returned for certain types of requests. For example, it can call hpdata_alloc_allowed_set(hpdata, false) during an update, at which point the given hpdata will no longer be returned for psset_pick_alloc requests. This has various of benefits: - It maintains stats correctness during purges and hugifies. - It allows simpler and more explicit concurrency control for the various special cases (e.g. allocations are disallowed during purge, but not during hugify). - It lets allocations and deallocations avoid disturbing the purging and hugification orderings. If an hpdata "loses its place" in one of the queues just do to an alloc / dalloc, it can result in pathological edge cases where very hot, very full hugepages never get hugified (and cold extents on the same hugepage as hot ones never get purged). The key benefit though is that tracking hpdatas to be purged / hugified in a principled way will let us do delayed purging and hugification. Eventually this will let us move these operations to background threads, but in the short term the benefit is that it will let us have global purging policies (e.g. purge when the entire arena has too many dirty pages, rather than any particular hugepage).
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hpdata_alloc_allowed_get(const hpdata_t *hpdata) {
return hpdata->h_alloc_allowed;
}
static inline void
hpdata_alloc_allowed_set(hpdata_t *hpdata, bool alloc_allowed) {
hpdata->h_alloc_allowed = alloc_allowed;
}
static inline bool
hpdata_in_psset_alloc_container_get(const hpdata_t *hpdata) {
return hpdata->h_in_psset_alloc_container;
}
static inline void
hpdata_in_psset_alloc_container_set(hpdata_t *hpdata, bool in_container) {
assert(in_container != hpdata->h_in_psset_alloc_container);
hpdata->h_in_psset_alloc_container = in_container;
}
static inline bool
hpdata_purge_allowed_get(const hpdata_t *hpdata) {
return hpdata->h_purge_allowed;
HPA: Track pending purges/hugifies in the psset. This finishes the refactoring of the HPA/psset interactions the past few commits have been building towards. Rather than the HPA removing and then reinserting hpdatas, it simply begins updates and ends them. These updates can set flags on the hpdata that prevent it from being returned for certain types of requests. For example, it can call hpdata_alloc_allowed_set(hpdata, false) during an update, at which point the given hpdata will no longer be returned for psset_pick_alloc requests. This has various of benefits: - It maintains stats correctness during purges and hugifies. - It allows simpler and more explicit concurrency control for the various special cases (e.g. allocations are disallowed during purge, but not during hugify). - It lets allocations and deallocations avoid disturbing the purging and hugification orderings. If an hpdata "loses its place" in one of the queues just do to an alloc / dalloc, it can result in pathological edge cases where very hot, very full hugepages never get hugified (and cold extents on the same hugepage as hot ones never get purged). The key benefit though is that tracking hpdatas to be purged / hugified in a principled way will let us do delayed purging and hugification. Eventually this will let us move these operations to background threads, but in the short term the benefit is that it will let us have global purging policies (e.g. purge when the entire arena has too many dirty pages, rather than any particular hugepage).
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}
static inline void
hpdata_purge_allowed_set(hpdata_t *hpdata, bool purge_allowed) {
assert(purge_allowed == false || !hpdata->h_mid_purge);
hpdata->h_purge_allowed = purge_allowed;
HPA: Track pending purges/hugifies in the psset. This finishes the refactoring of the HPA/psset interactions the past few commits have been building towards. Rather than the HPA removing and then reinserting hpdatas, it simply begins updates and ends them. These updates can set flags on the hpdata that prevent it from being returned for certain types of requests. For example, it can call hpdata_alloc_allowed_set(hpdata, false) during an update, at which point the given hpdata will no longer be returned for psset_pick_alloc requests. This has various of benefits: - It maintains stats correctness during purges and hugifies. - It allows simpler and more explicit concurrency control for the various special cases (e.g. allocations are disallowed during purge, but not during hugify). - It lets allocations and deallocations avoid disturbing the purging and hugification orderings. If an hpdata "loses its place" in one of the queues just do to an alloc / dalloc, it can result in pathological edge cases where very hot, very full hugepages never get hugified (and cold extents on the same hugepage as hot ones never get purged). The key benefit though is that tracking hpdatas to be purged / hugified in a principled way will let us do delayed purging and hugification. Eventually this will let us move these operations to background threads, but in the short term the benefit is that it will let us have global purging policies (e.g. purge when the entire arena has too many dirty pages, rather than any particular hugepage).
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}
static inline bool
hpdata_hugify_allowed_get(const hpdata_t *hpdata) {
return hpdata->h_hugify_allowed;
}
static inline void
hpdata_hugify_allowed_set(hpdata_t *hpdata, bool hugify_allowed) {
assert(hugify_allowed == false || !hpdata->h_mid_hugify);
HPA: Track pending purges/hugifies in the psset. This finishes the refactoring of the HPA/psset interactions the past few commits have been building towards. Rather than the HPA removing and then reinserting hpdatas, it simply begins updates and ends them. These updates can set flags on the hpdata that prevent it from being returned for certain types of requests. For example, it can call hpdata_alloc_allowed_set(hpdata, false) during an update, at which point the given hpdata will no longer be returned for psset_pick_alloc requests. This has various of benefits: - It maintains stats correctness during purges and hugifies. - It allows simpler and more explicit concurrency control for the various special cases (e.g. allocations are disallowed during purge, but not during hugify). - It lets allocations and deallocations avoid disturbing the purging and hugification orderings. If an hpdata "loses its place" in one of the queues just do to an alloc / dalloc, it can result in pathological edge cases where very hot, very full hugepages never get hugified (and cold extents on the same hugepage as hot ones never get purged). The key benefit though is that tracking hpdatas to be purged / hugified in a principled way will let us do delayed purging and hugification. Eventually this will let us move these operations to background threads, but in the short term the benefit is that it will let us have global purging policies (e.g. purge when the entire arena has too many dirty pages, rather than any particular hugepage).
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hpdata->h_hugify_allowed = hugify_allowed;
}
static inline bool
hpdata_in_psset_hugify_container_get(const hpdata_t *hpdata) {
return hpdata->h_in_psset_hugify_container;
}
static inline void
hpdata_in_psset_hugify_container_set(hpdata_t *hpdata, bool in_container) {
assert(in_container != hpdata->h_in_psset_hugify_container);
hpdata->h_in_psset_hugify_container = in_container;
}
static inline bool
hpdata_mid_purge_get(const hpdata_t *hpdata) {
return hpdata->h_mid_purge;
}
HPA: Track pending purges/hugifies in the psset. This finishes the refactoring of the HPA/psset interactions the past few commits have been building towards. Rather than the HPA removing and then reinserting hpdatas, it simply begins updates and ends them. These updates can set flags on the hpdata that prevent it from being returned for certain types of requests. For example, it can call hpdata_alloc_allowed_set(hpdata, false) during an update, at which point the given hpdata will no longer be returned for psset_pick_alloc requests. This has various of benefits: - It maintains stats correctness during purges and hugifies. - It allows simpler and more explicit concurrency control for the various special cases (e.g. allocations are disallowed during purge, but not during hugify). - It lets allocations and deallocations avoid disturbing the purging and hugification orderings. If an hpdata "loses its place" in one of the queues just do to an alloc / dalloc, it can result in pathological edge cases where very hot, very full hugepages never get hugified (and cold extents on the same hugepage as hot ones never get purged). The key benefit though is that tracking hpdatas to be purged / hugified in a principled way will let us do delayed purging and hugification. Eventually this will let us move these operations to background threads, but in the short term the benefit is that it will let us have global purging policies (e.g. purge when the entire arena has too many dirty pages, rather than any particular hugepage).
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static inline void
hpdata_mid_purge_set(hpdata_t *hpdata, bool mid_purge) {
assert(mid_purge != hpdata->h_mid_purge);
hpdata->h_mid_purge = mid_purge;
}
static inline bool
hpdata_mid_hugify_get(const hpdata_t *hpdata) {
return hpdata->h_mid_hugify;
}
HPA: Track pending purges/hugifies in the psset. This finishes the refactoring of the HPA/psset interactions the past few commits have been building towards. Rather than the HPA removing and then reinserting hpdatas, it simply begins updates and ends them. These updates can set flags on the hpdata that prevent it from being returned for certain types of requests. For example, it can call hpdata_alloc_allowed_set(hpdata, false) during an update, at which point the given hpdata will no longer be returned for psset_pick_alloc requests. This has various of benefits: - It maintains stats correctness during purges and hugifies. - It allows simpler and more explicit concurrency control for the various special cases (e.g. allocations are disallowed during purge, but not during hugify). - It lets allocations and deallocations avoid disturbing the purging and hugification orderings. If an hpdata "loses its place" in one of the queues just do to an alloc / dalloc, it can result in pathological edge cases where very hot, very full hugepages never get hugified (and cold extents on the same hugepage as hot ones never get purged). The key benefit though is that tracking hpdatas to be purged / hugified in a principled way will let us do delayed purging and hugification. Eventually this will let us move these operations to background threads, but in the short term the benefit is that it will let us have global purging policies (e.g. purge when the entire arena has too many dirty pages, rather than any particular hugepage).
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static inline void
hpdata_mid_hugify_set(hpdata_t *hpdata, bool mid_hugify) {
assert(mid_hugify != hpdata->h_mid_hugify);
hpdata->h_mid_hugify = mid_hugify;
}
static inline bool
hpdata_changing_state_get(const hpdata_t *hpdata) {
return hpdata->h_mid_purge || hpdata->h_mid_hugify;
}
static inline bool
hpdata_updating_get(const hpdata_t *hpdata) {
return hpdata->h_updating;
}
static inline void
hpdata_updating_set(hpdata_t *hpdata, bool updating) {
assert(updating != hpdata->h_updating);
hpdata->h_updating = updating;
}
static inline bool
hpdata_in_psset_get(const hpdata_t *hpdata) {
return hpdata->h_in_psset;
}
static inline void
hpdata_in_psset_set(hpdata_t *hpdata, bool in_psset) {
assert(in_psset != hpdata->h_in_psset);
hpdata->h_in_psset = in_psset;
}
static inline size_t
hpdata_longest_free_range_get(const hpdata_t *hpdata) {
return hpdata->h_longest_free_range;
}
static inline void
hpdata_longest_free_range_set(hpdata_t *hpdata, size_t longest_free_range) {
assert(longest_free_range <= HUGEPAGE_PAGES);
hpdata->h_longest_free_range = longest_free_range;
}
static inline size_t
hpdata_nactive_get(hpdata_t *hpdata) {
return hpdata->h_nactive;
}
static inline size_t
hpdata_ntouched_get(hpdata_t *hpdata) {
return hpdata->h_ntouched;
}
static inline size_t
hpdata_ndirty_get(hpdata_t *hpdata) {
return hpdata->h_ntouched - hpdata->h_nactive;
}
static inline size_t
hpdata_nretained_get(hpdata_t *hpdata) {
return hpdata->h_nactive - hpdata->h_ntouched;
}
static inline void
hpdata_assert_empty(hpdata_t *hpdata) {
assert(fb_empty(hpdata->active_pages, HUGEPAGE_PAGES));
assert(hpdata->h_nactive == 0);
}
/*
* Only used in tests, and in hpdata_assert_consistent, below. Verifies some
* consistency properties of the hpdata (e.g. that cached counts of page stats
* match computed ones).
*/
static inline bool
hpdata_consistent(hpdata_t *hpdata) {
if(fb_urange_longest(hpdata->active_pages, HUGEPAGE_PAGES)
!= hpdata_longest_free_range_get(hpdata)) {
return false;
}
if (fb_scount(hpdata->active_pages, HUGEPAGE_PAGES, 0, HUGEPAGE_PAGES)
!= hpdata->h_nactive) {
return false;
}
if (fb_scount(hpdata->touched_pages, HUGEPAGE_PAGES, 0, HUGEPAGE_PAGES)
!= hpdata->h_ntouched) {
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return false;
}
if (hpdata->h_ntouched < hpdata->h_nactive) {
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return false;
}
if (hpdata->h_huge && hpdata->h_ntouched != HUGEPAGE_PAGES) {
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return false;
}
if (hpdata_changing_state_get(hpdata)
&& ((hpdata->h_purge_allowed) || hpdata->h_hugify_allowed)) {
return false;
}
if (hpdata_hugify_allowed_get(hpdata)
!= hpdata_in_psset_hugify_container_get(hpdata)) {
return false;
}
return true;
}
static inline void
hpdata_assert_consistent(hpdata_t *hpdata) {
assert(hpdata_consistent(hpdata));
}
static inline bool
hpdata_empty(hpdata_t *hpdata) {
return hpdata->h_nactive == 0;
}
static inline bool
hpdata_full(hpdata_t *hpdata) {
return hpdata->h_nactive == HUGEPAGE_PAGES;
}
void hpdata_init(hpdata_t *hpdata, void *addr, uint64_t age);
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/*
* Given an hpdata which can serve an allocation request, pick and reserve an
* offset within that allocation.
*/
void *hpdata_reserve_alloc(hpdata_t *hpdata, size_t sz);
void hpdata_unreserve(hpdata_t *hpdata, void *begin, size_t sz);
/*
* The hpdata_purge_prepare_t allows grabbing the metadata required to purge
* subranges of a hugepage while holding a lock, drop the lock during the actual
* purging of them, and reacquire it to update the metadata again.
*/
typedef struct hpdata_purge_state_s hpdata_purge_state_t;
struct hpdata_purge_state_s {
size_t npurged;
size_t ndirty_to_purge;
fb_group_t to_purge[FB_NGROUPS(HUGEPAGE_PAGES)];
size_t next_purge_search_begin;
};
/*
* Initializes purge state. The access to hpdata must be externally
* synchronized with other hpdata_* calls.
*
* You can tell whether or not a thread is purging or hugifying a given hpdata
* via hpdata_changing_state_get(hpdata). Racing hugification or purging
* operations aren't allowed.
*
* Once you begin purging, you have to follow through and call hpdata_purge_next
* until you're done, and then end. Allocating out of an hpdata undergoing
* purging is not allowed.
*
* Returns the number of dirty pages that will be purged.
*/
size_t hpdata_purge_begin(hpdata_t *hpdata, hpdata_purge_state_t *purge_state);
/*
* If there are more extents to purge, sets *r_purge_addr and *r_purge_size to
* true, and returns true. Otherwise, returns false to indicate that we're
* done.
*
* This requires exclusive access to the purge state, but *not* to the hpdata.
* In particular, unreserve calls are allowed while purging (i.e. you can dalloc
* into one part of the hpdata while purging a different part).
*/
bool hpdata_purge_next(hpdata_t *hpdata, hpdata_purge_state_t *purge_state,
void **r_purge_addr, size_t *r_purge_size);
/*
* Updates the hpdata metadata after all purging is done. Needs external
* synchronization.
*/
void hpdata_purge_end(hpdata_t *hpdata, hpdata_purge_state_t *purge_state);
HPA: Track pending purges/hugifies in the psset. This finishes the refactoring of the HPA/psset interactions the past few commits have been building towards. Rather than the HPA removing and then reinserting hpdatas, it simply begins updates and ends them. These updates can set flags on the hpdata that prevent it from being returned for certain types of requests. For example, it can call hpdata_alloc_allowed_set(hpdata, false) during an update, at which point the given hpdata will no longer be returned for psset_pick_alloc requests. This has various of benefits: - It maintains stats correctness during purges and hugifies. - It allows simpler and more explicit concurrency control for the various special cases (e.g. allocations are disallowed during purge, but not during hugify). - It lets allocations and deallocations avoid disturbing the purging and hugification orderings. If an hpdata "loses its place" in one of the queues just do to an alloc / dalloc, it can result in pathological edge cases where very hot, very full hugepages never get hugified (and cold extents on the same hugepage as hot ones never get purged). The key benefit though is that tracking hpdatas to be purged / hugified in a principled way will let us do delayed purging and hugification. Eventually this will let us move these operations to background threads, but in the short term the benefit is that it will let us have global purging policies (e.g. purge when the entire arena has too many dirty pages, rather than any particular hugepage).
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void hpdata_hugify(hpdata_t *hpdata);
2020-12-03 09:56:58 +08:00
void hpdata_dehugify(hpdata_t *hpdata);
#endif /* JEMALLOC_INTERNAL_HPDATA_H */