From 58eba024c0fbda463eaf8b42772407894dba6eff Mon Sep 17 00:00:00 2001 From: Qi Wang Date: Tue, 31 Oct 2017 14:17:40 -0700 Subject: metadata_thp: auto mode adjustment for a0. We observed that arena 0 can have much more metadata allocated comparing to other arenas. Tune the auto mode to only switch to huge page on the 5th block (instead of 3 previously) for a0. --- include/jemalloc/internal/base_types.h | 9 ++++++++ src/base.c | 41 ++++++++++++++++++---------------- 2 files changed, 31 insertions(+), 19 deletions(-) diff --git a/include/jemalloc/internal/base_types.h b/include/jemalloc/internal/base_types.h index 97e38a9..b6db77d 100644 --- a/include/jemalloc/internal/base_types.h +++ b/include/jemalloc/internal/base_types.h @@ -6,6 +6,15 @@ typedef struct base_s base_t; #define METADATA_THP_DEFAULT metadata_thp_disabled +/* + * In auto mode, arenas switch to huge pages for the base allocator on the + * second base block. a0 switches to thp on the 5th block (after 20 megabytes + * of metadata), since more metadata (e.g. rtree nodes) come from a0's base. + */ + +#define BASE_AUTO_THP_THRESHOLD 2 +#define BASE_AUTO_THP_THRESHOLD_A0 5 + typedef enum { metadata_thp_disabled = 0, /* diff --git a/src/base.c b/src/base.c index c6db425..1036936 100644 --- a/src/base.c +++ b/src/base.c @@ -125,42 +125,45 @@ base_extent_init(size_t *extent_sn_next, extent_t *extent, void *addr, extent_binit(extent, addr, size, sn); } +static size_t +base_get_num_blocks(base_t *base, bool with_new_block) { + base_block_t *b = base->blocks; + assert(b != NULL); + + size_t n_blocks = with_new_block ? 2 : 1; + while (b->next != NULL) { + n_blocks++; + b = b->next; + } + + return n_blocks; +} + static bool base_auto_thp_triggered(base_t *base, bool with_new_block) { assert(opt_metadata_thp == metadata_thp_auto); - base_block_t *b1 = base->blocks; - assert(b1 != NULL); - base_block_t *b2 = b1->next; if (base_ind_get(base) != 0) { - return with_new_block ? true: b2 != NULL; + return base_get_num_blocks(base, with_new_block) >= + BASE_AUTO_THP_THRESHOLD; } - base_block_t *b3 = (b2 != NULL) ? b2->next : NULL; - return with_new_block ? b2 != NULL : b3 != NULL; + return base_get_num_blocks(base, with_new_block) >= + BASE_AUTO_THP_THRESHOLD_A0; } static void base_auto_thp_switch(base_t *base) { assert(opt_metadata_thp == metadata_thp_auto); - base_block_t *b1 = base->blocks; - assert(b1 != NULL); - base_block_t *b2 = b1->next; - /* Called when adding a new block. */ bool should_switch; if (base_ind_get(base) != 0) { - /* Makes the switch on the 2nd block. */ - should_switch = (b2 == NULL); + should_switch = (base_get_num_blocks(base, true) == + BASE_AUTO_THP_THRESHOLD); } else { - /* - * a0 switches to thp on the 3rd block, since rtree nodes are - * allocated from a0 base, which takes an entire block on init. - */ - base_block_t *b3 = (b2 != NULL) ? b2->next : - NULL; - should_switch = (b2 != NULL) && (b3 == NULL); + should_switch = (base_get_num_blocks(base, true) == + BASE_AUTO_THP_THRESHOLD_A0); } if (!should_switch) { return; -- cgit v0.12