hpdata: track per-page dirty state.

This commit is contained in:
David Goldblatt 2020-12-02 17:56:58 -08:00 committed by David Goldblatt
parent ff4086aa6b
commit 2ae966222f
3 changed files with 85 additions and 9 deletions

View File

@ -52,6 +52,16 @@ struct hpdata_s {
/* A bitmap with bits set in the active pages. */ /* A bitmap with bits set in the active pages. */
fb_group_t active_pages[FB_NGROUPS(HUGEPAGE_PAGES)]; fb_group_t active_pages[FB_NGROUPS(HUGEPAGE_PAGES)];
/*
* Number of dirty pages, and a bitmap tracking them. This really means
* "dirty" from the OS's point of view; it includes both active and
* inactive pages that have been touched by the user.
*/
size_t h_ndirty;
/* The dirty pages (using the same definition as above). */
fb_group_t dirty_pages[FB_NGROUPS(HUGEPAGE_PAGES)];
}; };
static inline void * static inline void *
@ -80,11 +90,6 @@ hpdata_huge_get(const hpdata_t *hpdata) {
return hpdata->h_huge; return hpdata->h_huge;
} }
static inline void
hpdata_huge_set(hpdata_t *hpdata, bool huge) {
hpdata->h_huge = huge;
}
static inline size_t static inline size_t
hpdata_longest_free_range_get(const hpdata_t *hpdata) { hpdata_longest_free_range_get(const hpdata_t *hpdata) {
return hpdata->h_longest_free_range; return hpdata->h_longest_free_range;
@ -122,6 +127,16 @@ hpdata_consistent(hpdata_t *hpdata) {
!= hpdata->h_nactive) { != hpdata->h_nactive) {
return false; return false;
} }
if (fb_scount(hpdata->dirty_pages, HUGEPAGE_PAGES, 0, HUGEPAGE_PAGES)
!= hpdata->h_ndirty) {
return false;
}
if (hpdata->h_ndirty < hpdata->h_nactive) {
return false;
}
if (hpdata->h_huge && hpdata->h_ndirty != HUGEPAGE_PAGES) {
return false;
}
return true; return true;
} }
@ -141,6 +156,7 @@ hpdata_empty(hpdata_t *hpdata) {
} }
void hpdata_init(hpdata_t *hpdata, void *addr, uint64_t age); void hpdata_init(hpdata_t *hpdata, void *addr, uint64_t age);
/* /*
* Given an hpdata which can serve an allocation request, pick and reserve an * Given an hpdata which can serve an allocation request, pick and reserve an
* offset within that allocation. * offset within that allocation.
@ -148,4 +164,20 @@ void hpdata_init(hpdata_t *hpdata, void *addr, uint64_t age);
void *hpdata_reserve_alloc(hpdata_t *hpdata, size_t sz); void *hpdata_reserve_alloc(hpdata_t *hpdata, size_t sz);
void hpdata_unreserve(hpdata_t *hpdata, void *begin, size_t sz); void hpdata_unreserve(hpdata_t *hpdata, void *begin, size_t sz);
/*
* Tell the hpdata that it's now a hugepage (which, correspondingly, means that
* all its pages become dirty.
*/
void hpdata_hugify(hpdata_t *hpdata);
/*
* Tell the hpdata that it's no longer a hugepage (all its pages are still
* counted as dirty, though; an explicit purge call is required to change that).
*/
void hpdata_dehugify(hpdata_t *hpdata);
/*
* Tell the hpdata (which should be empty) that all dirty pages in it have been
* purged.
*/
void hpdata_purge(hpdata_t *hpdata);
#endif /* JEMALLOC_INTERNAL_HPDATA_H */ #endif /* JEMALLOC_INTERNAL_HPDATA_H */

View File

@ -146,7 +146,10 @@ hpa_dehugify(hpdata_t *ps) {
/* Purge, then dehugify while unbacked. */ /* Purge, then dehugify while unbacked. */
pages_purge_forced(hpdata_addr_get(ps), HUGEPAGE); pages_purge_forced(hpdata_addr_get(ps), HUGEPAGE);
pages_nohuge(hpdata_addr_get(ps), HUGEPAGE); pages_nohuge(hpdata_addr_get(ps), HUGEPAGE);
hpdata_huge_set(ps, false);
/* Update metadata. */
hpdata_dehugify(ps);
hpdata_purge(ps);
} }
static hpdata_t * static hpdata_t *
@ -297,7 +300,7 @@ hpa_try_alloc_no_grow(tsdn_t *tsdn, hpa_shard_t *shard, size_t size, bool *oom)
bool hugify = hpa_should_hugify(shard, ps); bool hugify = hpa_should_hugify(shard, ps);
if (hugify) { if (hugify) {
hpdata_huge_set(ps, true); hpdata_hugify(ps);
} }
psset_insert(&shard->psset, ps); psset_insert(&shard->psset, ps);

View File

@ -21,10 +21,12 @@ void
hpdata_init(hpdata_t *hpdata, void *addr, uint64_t age) { hpdata_init(hpdata_t *hpdata, void *addr, uint64_t age) {
hpdata_addr_set(hpdata, addr); hpdata_addr_set(hpdata, addr);
hpdata_age_set(hpdata, age); hpdata_age_set(hpdata, age);
hpdata_huge_set(hpdata, false); hpdata->h_huge = false;
hpdata->h_nactive = 0;
hpdata_longest_free_range_set(hpdata, HUGEPAGE_PAGES); hpdata_longest_free_range_set(hpdata, HUGEPAGE_PAGES);
hpdata->h_nactive = 0;
fb_init(hpdata->active_pages, HUGEPAGE_PAGES); fb_init(hpdata->active_pages, HUGEPAGE_PAGES);
hpdata->h_ndirty = 0;
fb_init(hpdata->dirty_pages, HUGEPAGE_PAGES);
hpdata_assert_consistent(hpdata); hpdata_assert_consistent(hpdata);
} }
@ -74,6 +76,15 @@ hpdata_reserve_alloc(hpdata_t *hpdata, size_t sz) {
fb_set_range(hpdata->active_pages, HUGEPAGE_PAGES, begin, npages); fb_set_range(hpdata->active_pages, HUGEPAGE_PAGES, begin, npages);
hpdata->h_nactive += npages; hpdata->h_nactive += npages;
/*
* We might be about to dirty some memory for the first time; update our
* count if so.
*/
size_t new_dirty = fb_ucount(hpdata->dirty_pages, HUGEPAGE_PAGES,
result, npages);
fb_set_range(hpdata->dirty_pages, HUGEPAGE_PAGES, result, npages);
hpdata->h_ndirty += new_dirty;
/* /*
* We might have shrunk the longest free range. We have to keep * We might have shrunk the longest free range. We have to keep
* scanning until the end of the hpdata to be sure. * scanning until the end of the hpdata to be sure.
@ -127,3 +138,33 @@ hpdata_unreserve(hpdata_t *hpdata, void *addr, size_t sz) {
hpdata_assert_consistent(hpdata); hpdata_assert_consistent(hpdata);
} }
void
hpdata_hugify(hpdata_t *hpdata) {
hpdata_assert_consistent(hpdata);
hpdata->h_huge = true;
fb_set_range(hpdata->dirty_pages, HUGEPAGE_PAGES, 0, HUGEPAGE_PAGES);
hpdata->h_ndirty = HUGEPAGE_PAGES;
hpdata_assert_consistent(hpdata);
}
void
hpdata_dehugify(hpdata_t *hpdata) {
hpdata_assert_consistent(hpdata);
hpdata->h_huge = false;
hpdata_assert_consistent(hpdata);
}
void
hpdata_purge(hpdata_t *hpdata) {
hpdata_assert_consistent(hpdata);
/*
* The hpdata must be empty; we don't (yet) support partial purges of
* hugepages.
*/
assert(hpdata->h_nactive == 0);
fb_unset_range(hpdata->dirty_pages, HUGEPAGE_PAGES, 0, HUGEPAGE_PAGES);
fb_init(hpdata->dirty_pages, HUGEPAGE_PAGES);
hpdata->h_ndirty = 0;
hpdata_assert_consistent(hpdata);
}