From 6bddb92ad64ee096a34c0d099736c237d46f1065 Mon Sep 17 00:00:00 2001 From: David Goldblatt Date: Mon, 8 Feb 2021 11:26:56 -0800 Subject: [PATCH] psset: Rename "bitmap" to "pageslab_bitmap". It tracks pageslabs. Soon, we'll have another bitmap (to track dirty pages) that we want to disambiguate. While we're here, fix an out-of-date comment. --- include/jemalloc/internal/psset.h | 2 +- src/psset.c | 19 +++++++------------ 2 files changed, 8 insertions(+), 13 deletions(-) diff --git a/include/jemalloc/internal/psset.h b/include/jemalloc/internal/psset.h index 2b6ea7bc..271d1443 100644 --- a/include/jemalloc/internal/psset.h +++ b/include/jemalloc/internal/psset.h @@ -57,7 +57,7 @@ struct psset_s { */ hpdata_age_heap_t pageslabs[PSSET_NPSIZES]; /* Bitmap for which set bits correspond to non-empty heaps. */ - fb_group_t bitmap[FB_NGROUPS(PSSET_NPSIZES)]; + fb_group_t pageslab_bitmap[FB_NGROUPS(PSSET_NPSIZES)]; /* * The sum of all bin stats in stats. This lets us quickly answer * queries for the number of dirty, active, and retained pages in the diff --git a/src/psset.c b/src/psset.c index a54e4b75..66fd0c49 100644 --- a/src/psset.c +++ b/src/psset.c @@ -10,7 +10,7 @@ psset_init(psset_t *psset) { for (unsigned i = 0; i < PSSET_NPSIZES; i++) { hpdata_age_heap_new(&psset->pageslabs[i]); } - fb_init(psset->bitmap, PSSET_NPSIZES); + fb_init(psset->pageslab_bitmap, PSSET_NPSIZES); memset(&psset->merged_stats, 0, sizeof(psset->merged_stats)); memset(&psset->stats, 0, sizeof(psset->stats)); hpdata_empty_list_init(&psset->empty); @@ -40,14 +40,9 @@ psset_stats_accum(psset_stats_t *dst, psset_stats_t *src) { } /* - * The stats maintenance strategy is simple, but not necessarily obvious. - * edata_nfree and the bitmap must remain consistent at all times. If they - * change while an edata is within an edata_heap (or full), then the associated - * stats bin (or the full bin) must also change. If they change while not in a - * bin (say, in between extraction and reinsertion), then the bin stats need not - * change. If a pageslab is removed from a bin (or becomes nonfull), it should - * no longer contribute to that bin's stats (or the full stats). These help - * ensure we don't miss any heap modification operations. + * The stats maintenance strategy is to remove a pageslab's contribution to the + * stats when we call psset_update_begin, and re-add it (to a potentially new + * bin) when we call psset_update_end. */ JEMALLOC_ALWAYS_INLINE void psset_bin_stats_insert_remove(psset_t *psset, psset_bin_stats_t *binstats, @@ -98,14 +93,14 @@ static void psset_hpdata_heap_remove(psset_t *psset, pszind_t pind, hpdata_t *ps) { hpdata_age_heap_remove(&psset->pageslabs[pind], ps); if (hpdata_age_heap_empty(&psset->pageslabs[pind])) { - fb_unset(psset->bitmap, PSSET_NPSIZES, (size_t)pind); + fb_unset(psset->pageslab_bitmap, PSSET_NPSIZES, (size_t)pind); } } static void psset_hpdata_heap_insert(psset_t *psset, pszind_t pind, hpdata_t *ps) { if (hpdata_age_heap_empty(&psset->pageslabs[pind])) { - fb_set(psset->bitmap, PSSET_NPSIZES, (size_t)pind); + fb_set(psset->pageslab_bitmap, PSSET_NPSIZES, (size_t)pind); } hpdata_age_heap_insert(&psset->pageslabs[pind], ps); } @@ -263,7 +258,7 @@ psset_pick_alloc(psset_t *psset, size_t size) { assert(size <= HUGEPAGE); pszind_t min_pind = sz_psz2ind(sz_psz_quantize_ceil(size)); - pszind_t pind = (pszind_t)fb_ffs(psset->bitmap, PSSET_NPSIZES, + pszind_t pind = (pszind_t)fb_ffs(psset->pageslab_bitmap, PSSET_NPSIZES, (size_t)min_pind); if (pind == PSSET_NPSIZES) { return hpdata_empty_list_first(&psset->empty);