1 files changed, 325 insertions, 0 deletions

diff --git a/deps/jemalloc/src/hpdata.c b/deps/jemalloc/src/hpdata.c
new file mode 100644
index 000000000..e7d7294c7
--- /dev/null
+++ b/deps/jemalloc/src/hpdata.c
@@ -0,0 +1,325 @@
+#include "jemalloc/internal/jemalloc_preamble.h"
+#include "jemalloc/internal/jemalloc_internal_includes.h"
+
+#include "jemalloc/internal/hpdata.h"
+
+static int
+hpdata_age_comp(const hpdata_t *a, const hpdata_t *b) {
+	uint64_t a_age = hpdata_age_get(a);
+	uint64_t b_age = hpdata_age_get(b);
+	/*
+	 * hpdata ages are operation counts in the psset; no two should be the
+	 * same.
+	 */
+	assert(a_age != b_age);
+	return (a_age > b_age) - (a_age < b_age);
+}
+
+ph_gen(, hpdata_age_heap, hpdata_t, age_link, hpdata_age_comp)
+
+void
+hpdata_init(hpdata_t *hpdata, void *addr, uint64_t age) {
+	hpdata_addr_set(hpdata, addr);
+	hpdata_age_set(hpdata, age);
+	hpdata->h_huge = false;
+	hpdata->h_alloc_allowed = true;
+	hpdata->h_in_psset_alloc_container = false;
+	hpdata->h_purge_allowed = false;
+	hpdata->h_hugify_allowed = false;
+	hpdata->h_in_psset_hugify_container = false;
+	hpdata->h_mid_purge = false;
+	hpdata->h_mid_hugify = false;
+	hpdata->h_updating = false;
+	hpdata->h_in_psset = false;
+	hpdata_longest_free_range_set(hpdata, HUGEPAGE_PAGES);
+	hpdata->h_nactive = 0;
+	fb_init(hpdata->active_pages, HUGEPAGE_PAGES);
+	hpdata->h_ntouched = 0;
+	fb_init(hpdata->touched_pages, HUGEPAGE_PAGES);
+
+	hpdata_assert_consistent(hpdata);
+}
+
+void *
+hpdata_reserve_alloc(hpdata_t *hpdata, size_t sz) {
+	hpdata_assert_consistent(hpdata);
+	/*
+	 * This is a metadata change; the hpdata should therefore either not be
+	 * in the psset, or should have explicitly marked itself as being
+	 * mid-update.
+	 */
+	assert(!hpdata->h_in_psset || hpdata->h_updating);
+	assert(hpdata->h_alloc_allowed);
+	assert((sz & PAGE_MASK) == 0);
+	size_t npages = sz >> LG_PAGE;
+	assert(npages <= hpdata_longest_free_range_get(hpdata));
+
+	size_t result;
+
+	size_t start = 0;
+	/*
+	 * These are dead stores, but the compiler will issue warnings on them
+	 * since it can't tell statically that found is always true below.
+	 */
+	size_t begin = 0;
+	size_t len = 0;
+
+	size_t largest_unchosen_range = 0;
+	while (true) {
+		bool found = fb_urange_iter(hpdata->active_pages,
+		    HUGEPAGE_PAGES, start, &begin, &len);
+		/*
+		 * A precondition to this function is that hpdata must be able
+		 * to serve the allocation.
+		 */
+		assert(found);
+		assert(len <= hpdata_longest_free_range_get(hpdata));
+		if (len >= npages) {
+			/*
+			 * We use first-fit within the page slabs; this gives
+			 * bounded worst-case fragmentation within a slab.  It's
+			 * not necessarily right; we could experiment with
+			 * various other options.
+			 */
+			break;
+		}
+		if (len > largest_unchosen_range) {
+			largest_unchosen_range = len;
+		}
+		start = begin + len;
+	}
+	/* We found a range; remember it. */
+	result = begin;
+	fb_set_range(hpdata->active_pages, HUGEPAGE_PAGES, begin, 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->touched_pages,  HUGEPAGE_PAGES,
+	    result, npages);
+	fb_set_range(hpdata->touched_pages, HUGEPAGE_PAGES, result, npages);
+	hpdata->h_ntouched += new_dirty;
+
+	/*
+	 * If we allocated out of a range that was the longest in the hpdata, it
+	 * might be the only one of that size and we'll have to adjust the
+	 * metadata.
+	 */
+	if (len == hpdata_longest_free_range_get(hpdata)) {
+		start = begin + npages;
+		while (start < HUGEPAGE_PAGES) {
+			bool found = fb_urange_iter(hpdata->active_pages,
+			    HUGEPAGE_PAGES, start, &begin, &len);
+			if (!found) {
+				break;
+			}
+			assert(len <= hpdata_longest_free_range_get(hpdata));
+			if (len == hpdata_longest_free_range_get(hpdata)) {
+				largest_unchosen_range = len;
+				break;
+			}
+			if (len > largest_unchosen_range) {
+				largest_unchosen_range = len;
+			}
+			start = begin + len;
+		}
+		hpdata_longest_free_range_set(hpdata, largest_unchosen_range);
+	}
+
+	hpdata_assert_consistent(hpdata);
+	return (void *)(
+	    (uintptr_t)hpdata_addr_get(hpdata) + (result << LG_PAGE));
+}
+
+void
+hpdata_unreserve(hpdata_t *hpdata, void *addr, size_t sz) {
+	hpdata_assert_consistent(hpdata);
+	/* See the comment in reserve. */
+	assert(!hpdata->h_in_psset || hpdata->h_updating);
+	assert(((uintptr_t)addr & PAGE_MASK) == 0);
+	assert((sz & PAGE_MASK) == 0);
+	size_t begin = ((uintptr_t)addr - (uintptr_t)hpdata_addr_get(hpdata))
+	    >> LG_PAGE;
+	assert(begin < HUGEPAGE_PAGES);
+	size_t npages = sz >> LG_PAGE;
+	size_t old_longest_range = hpdata_longest_free_range_get(hpdata);
+
+	fb_unset_range(hpdata->active_pages, HUGEPAGE_PAGES, begin, npages);
+	/* We might have just created a new, larger range. */
+	size_t new_begin = (fb_fls(hpdata->active_pages, HUGEPAGE_PAGES,
+	    begin) + 1);
+	size_t new_end = fb_ffs(hpdata->active_pages, HUGEPAGE_PAGES,
+	    begin + npages - 1);
+	size_t new_range_len = new_end - new_begin;
+
+	if (new_range_len > old_longest_range) {
+		hpdata_longest_free_range_set(hpdata, new_range_len);
+	}
+
+	hpdata->h_nactive -= npages;
+
+	hpdata_assert_consistent(hpdata);
+}
+
+size_t
+hpdata_purge_begin(hpdata_t *hpdata, hpdata_purge_state_t *purge_state) {
+	hpdata_assert_consistent(hpdata);
+	/*
+	 * See the comment below; we might purge any inactive extent, so it's
+	 * unsafe for any other thread to turn any inactive extent active while
+	 * we're operating on it.
+	 */
+	assert(!hpdata_alloc_allowed_get(hpdata));
+
+	purge_state->npurged = 0;
+	purge_state->next_purge_search_begin = 0;
+
+	/*
+	 * Initialize to_purge.
+	 *
+	 * It's possible to end up in situations where two dirty extents are
+	 * separated by a retained extent:
+	 * - 1 page allocated.
+	 * - 1 page allocated.
+	 * - 1 pages allocated.
+	 *
+	 * If the middle page is freed and purged, and then the first and third
+	 * pages are freed, and then another purge pass happens, the hpdata
+	 * looks like this:
+	 * - 1 page dirty.
+	 * - 1 page retained.
+	 * - 1 page dirty.
+	 *
+	 * But it's safe to do a single 3-page purge.
+	 *
+	 * We do this by first computing the dirty pages, and then filling in
+	 * any gaps by extending each range in the dirty bitmap to extend until
+	 * the next active page.  This purges more pages, but the expensive part
+	 * of purging is the TLB shootdowns, rather than the kernel state
+	 * tracking; doing a little bit more of the latter is fine if it saves
+	 * us from doing some of the former.
+	 */
+
+	/*
+	 * The dirty pages are those that are touched but not active.  Note that
+	 * in a normal-ish case, HUGEPAGE_PAGES is something like 512 and the
+	 * fb_group_t is 64 bits, so this is 64 bytes, spread across 8
+	 * fb_group_ts.
+	 */
+	fb_group_t dirty_pages[FB_NGROUPS(HUGEPAGE_PAGES)];
+	fb_init(dirty_pages, HUGEPAGE_PAGES);
+	fb_bit_not(dirty_pages, hpdata->active_pages, HUGEPAGE_PAGES);
+	fb_bit_and(dirty_pages, dirty_pages, hpdata->touched_pages,
+	    HUGEPAGE_PAGES);
+
+	fb_init(purge_state->to_purge, HUGEPAGE_PAGES);
+	size_t next_bit = 0;
+	while (next_bit < HUGEPAGE_PAGES) {
+		size_t next_dirty = fb_ffs(dirty_pages, HUGEPAGE_PAGES,
+		    next_bit);
+		/* Recall that fb_ffs returns nbits if no set bit is found. */
+		if (next_dirty == HUGEPAGE_PAGES) {
+			break;
+		}
+		size_t next_active = fb_ffs(hpdata->active_pages,
+		    HUGEPAGE_PAGES, next_dirty);
+		/*
+		 * Don't purge past the end of the dirty extent, into retained
+		 * pages.  This helps the kernel a tiny bit, but honestly it's
+		 * mostly helpful for testing (where we tend to write test cases
+		 * that think in terms of the dirty ranges).
+		 */
+		ssize_t last_dirty = fb_fls(dirty_pages, HUGEPAGE_PAGES,
+		    next_active - 1);
+		assert(last_dirty >= 0);
+		assert((size_t)last_dirty >= next_dirty);
+		assert((size_t)last_dirty - next_dirty + 1 <= HUGEPAGE_PAGES);
+
+		fb_set_range(purge_state->to_purge, HUGEPAGE_PAGES, next_dirty,
+		    last_dirty - next_dirty + 1);
+		next_bit = next_active + 1;
+	}
+
+	/* We should purge, at least, everything dirty. */
+	size_t ndirty = hpdata->h_ntouched - hpdata->h_nactive;
+	purge_state->ndirty_to_purge = ndirty;
+	assert(ndirty <= fb_scount(
+	    purge_state->to_purge, HUGEPAGE_PAGES, 0, HUGEPAGE_PAGES));
+	assert(ndirty == fb_scount(dirty_pages, HUGEPAGE_PAGES, 0,
+	    HUGEPAGE_PAGES));
+
+	hpdata_assert_consistent(hpdata);
+
+	return ndirty;
+}
+
+bool
+hpdata_purge_next(hpdata_t *hpdata, hpdata_purge_state_t *purge_state,
+    void **r_purge_addr, size_t *r_purge_size) {
+	/*
+	 * Note that we don't have a consistency check here; we're accessing
+	 * hpdata without synchronization, and therefore have no right to expect
+	 * a consistent state.
+	 */
+	assert(!hpdata_alloc_allowed_get(hpdata));
+
+	if (purge_state->next_purge_search_begin == HUGEPAGE_PAGES) {
+		return false;
+	}
+	size_t purge_begin;
+	size_t purge_len;
+	bool found_range = fb_srange_iter(purge_state->to_purge, HUGEPAGE_PAGES,
+	    purge_state->next_purge_search_begin, &purge_begin, &purge_len);
+	if (!found_range) {
+		return false;
+	}
+
+	*r_purge_addr = (void *)(
+	    (uintptr_t)hpdata_addr_get(hpdata) + purge_begin * PAGE);
+	*r_purge_size = purge_len * PAGE;
+
+	purge_state->next_purge_search_begin = purge_begin + purge_len;
+	purge_state->npurged += purge_len;
+	assert(purge_state->npurged <= HUGEPAGE_PAGES);
+
+	return true;
+}
+
+void
+hpdata_purge_end(hpdata_t *hpdata, hpdata_purge_state_t *purge_state) {
+	assert(!hpdata_alloc_allowed_get(hpdata));
+	hpdata_assert_consistent(hpdata);
+	/* See the comment in reserve. */
+	assert(!hpdata->h_in_psset || hpdata->h_updating);
+
+	assert(purge_state->npurged == fb_scount(purge_state->to_purge,
+	    HUGEPAGE_PAGES, 0, HUGEPAGE_PAGES));
+	assert(purge_state->npurged >= purge_state->ndirty_to_purge);
+
+	fb_bit_not(purge_state->to_purge, purge_state->to_purge,
+	    HUGEPAGE_PAGES);
+	fb_bit_and(hpdata->touched_pages, hpdata->touched_pages,
+	    purge_state->to_purge, HUGEPAGE_PAGES);
+	assert(hpdata->h_ntouched >= purge_state->ndirty_to_purge);
+	hpdata->h_ntouched -= purge_state->ndirty_to_purge;
+
+	hpdata_assert_consistent(hpdata);
+}
+
+void
+hpdata_hugify(hpdata_t *hpdata) {
+	hpdata_assert_consistent(hpdata);
+	hpdata->h_huge = true;
+	fb_set_range(hpdata->touched_pages, HUGEPAGE_PAGES, 0, HUGEPAGE_PAGES);
+	hpdata->h_ntouched = HUGEPAGE_PAGES;
+	hpdata_assert_consistent(hpdata);
+}
+
+void
+hpdata_dehugify(hpdata_t *hpdata) {
+	hpdata_assert_consistent(hpdata);
+	hpdata->h_huge = false;
+	hpdata_assert_consistent(hpdata);
+}