From 8a462e5a662a6da97060162f0b9220c60ebfdd8c Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Sat, 25 Sep 2010 13:59:00 +0930 Subject: [PATCH] tdb2: Move min size constant out where summary.c can see it. --- ccan/tdb2/free.c | 27 ++++++++++++++++----------- ccan/tdb2/private.h | 4 ++++ 2 files changed, 20 insertions(+), 11 deletions(-) diff --git a/ccan/tdb2/free.c b/ccan/tdb2/free.c index 36117190..5284510a 100644 --- a/ccan/tdb2/free.c +++ b/ccan/tdb2/free.c @@ -21,10 +21,6 @@ #include #include -/* We have to be able to fit a free record here. */ -#define MIN_DATA_LEN \ - (sizeof(struct tdb_free_record) - sizeof(struct tdb_used_record)) - static unsigned fls64(uint64_t val) { #if HAVE_BUILTIN_CLZL @@ -73,15 +69,15 @@ unsigned int size_to_bucket(unsigned int zone_bits, tdb_len_t data_len) unsigned int bucket; /* We can't have records smaller than this. */ - assert(data_len >= MIN_DATA_LEN); + assert(data_len >= TDB_MIN_DATA_LEN); /* Ignoring the header... */ - if (data_len - MIN_DATA_LEN <= 64) { - /* 0 in bucket 0, 8 in bucket 1... 64 in bucket 6. */ - bucket = (data_len - MIN_DATA_LEN) / 8; + if (data_len - TDB_MIN_DATA_LEN <= 64) { + /* 0 in bucket 0, 8 in bucket 1... 64 in bucket 8. */ + bucket = (data_len - TDB_MIN_DATA_LEN) / 8; } else { /* After that we go power of 2. */ - bucket = fls64(data_len - MIN_DATA_LEN) + 2; + bucket = fls64(data_len - TDB_MIN_DATA_LEN) + 2; } if (unlikely(bucket > BUCKETS_FOR_ZONE(zone_bits))) @@ -369,6 +365,9 @@ static tdb_off_t lock_and_alloc(struct tdb_context *tdb, again: b_off = bucket_off(zone_off, bucket); + /* FIXME: Try non-blocking wait first, to measure contention. + * If we're contented, try switching zones, and don't enlarge zone + * next time (we want more zones). */ /* Lock this bucket. */ if (tdb_lock_free_bucket(tdb, b_off, TDB_LOCK_WAIT) == -1) { return TDB_OFF_ERR; @@ -463,6 +462,10 @@ static tdb_off_t get_free(struct tdb_context *tdb, size_t size, tdb_off_t start_zone = tdb->zone_off, off; bool wrapped = false; + /* FIXME: If we don't get a hit in the first bucket we want, + * try changing zones for next time. That should help wear + * zones evenly, so we don't need to search all of them before + * expanding. */ while (!wrapped || tdb->zone_off != start_zone) { tdb_off_t b; @@ -567,6 +570,7 @@ static int tdb_expand(struct tdb_context *tdb, tdb_len_t size) if (tdb->map_size != old_size) goto success; + /* FIXME: Tailer is a bogus optimization, remove it. */ /* zone bits tailer char is protected by EXPAND lock. */ if (tdb->methods->read(tdb, old_size - 1, &zone_bits, 1) == -1) goto fail; @@ -593,6 +597,7 @@ static int tdb_expand(struct tdb_context *tdb, tdb_len_t size) zhdr.zone_bits = zone_bits; num_buckets = BUCKETS_FOR_ZONE(zone_bits); + /* FIXME: I don't think we need to expand to full zone, do we? */ if (tdb->methods->expand_file(tdb, 1ULL << zone_bits) == -1) goto fail; @@ -632,8 +637,8 @@ static tdb_len_t adjust_size(size_t keylen, size_t datalen, bool growing) { tdb_len_t size = keylen + datalen; - if (size < MIN_DATA_LEN) - size = MIN_DATA_LEN; + if (size < TDB_MIN_DATA_LEN) + size = TDB_MIN_DATA_LEN; /* Overallocate if this is coming from an enlarging store. */ if (growing) diff --git a/ccan/tdb2/private.h b/ccan/tdb2/private.h index 19d7866d..c0377363 100644 --- a/ccan/tdb2/private.h +++ b/ccan/tdb2/private.h @@ -113,6 +113,10 @@ typedef uint64_t tdb_off_t; #define TDB_OFF_MASK \ (((1ULL << (64 - TDB_OFF_UPPER_STEAL)) - 1) - TDB_OFF_HASH_GROUP_MASK) +/* We have to be able to fit a free record here. */ +#define TDB_MIN_DATA_LEN \ + (sizeof(struct tdb_free_record) - sizeof(struct tdb_used_record)) + /* We ensure buckets up to size 1 << (zone_bits - TDB_COMFORT_FACTOR_BITS). */ /* FIXME: test this matches size_to_bucket! */ #define BUCKETS_FOR_ZONE(zone_bits) ((zone_bits) + 2 - TDB_COMFORT_FACTOR_BITS) -- 2.39.2