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ZAP: Some cleanups/micro-optimizations
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 - Remove custom zap_memset(), use regular memset().
 - Use PANIC() instead of opaque cmn_err(CE_PANIC).
 - Provide entry parameter to zap_leaf_rehash_entry().
 - Reduce branching in zap_leaf_array_create() inner loop.
 - Remove signedness where it should not be.

Should be no function changes.

Signed-off-by:	Alexander Motin <[email protected]>
Sponsored by:	iXsystems, Inc.
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@amotin
amotin committed Mar 8, 2024
1 parent 8f2f6cd commit ab6a2ab
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Showing 2 changed files with 38 additions and 47 deletions.
8 changes: 4 additions & 4 deletions include/sys/zap_leaf.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,7 +47,7 @@ struct zap_stats;
* entries - header space (2*chunksize)
*/
#define ZAP_LEAF_NUMCHUNKS_BS(bs) \
(((1<<(bs)) - 2*ZAP_LEAF_HASH_NUMENTRIES_BS(bs)) / \
(((1U << (bs)) - 2 * ZAP_LEAF_HASH_NUMENTRIES_BS(bs)) / \
ZAP_LEAF_CHUNKSIZE - 2)

#define ZAP_LEAF_NUMCHUNKS(l) (ZAP_LEAF_NUMCHUNKS_BS(((l)->l_bs)))
Expand Down Expand Up @@ -80,7 +80,7 @@ struct zap_stats;
* chunks per entry (3).
*/
#define ZAP_LEAF_HASH_SHIFT_BS(bs) ((bs) - 5)
#define ZAP_LEAF_HASH_NUMENTRIES_BS(bs) (1 << ZAP_LEAF_HASH_SHIFT_BS(bs))
#define ZAP_LEAF_HASH_NUMENTRIES_BS(bs) (1U << ZAP_LEAF_HASH_SHIFT_BS(bs))
#define ZAP_LEAF_HASH_SHIFT(l) (ZAP_LEAF_HASH_SHIFT_BS(((l)->l_bs)))
#define ZAP_LEAF_HASH_NUMENTRIES(l) (ZAP_LEAF_HASH_NUMENTRIES_BS(((l)->l_bs)))

Expand Down Expand Up @@ -163,7 +163,7 @@ typedef struct zap_leaf {
dmu_buf_user_t l_dbu;
krwlock_t l_rwlock;
uint64_t l_blkid; /* 1<<ZAP_BLOCK_SHIFT byte block off */
int l_bs; /* block size shift */
uint_t l_bs; /* block size shift */
dmu_buf_t *l_dbuf;
} zap_leaf_t;

Expand Down Expand Up @@ -243,7 +243,7 @@ extern boolean_t zap_entry_normalization_conflict(zap_entry_handle_t *zeh,
*/

extern void zap_leaf_init(zap_leaf_t *l, boolean_t sort);
extern void zap_leaf_byteswap(zap_leaf_phys_t *buf, int len);
extern void zap_leaf_byteswap(zap_leaf_phys_t *buf, size_t len);
extern void zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort);
extern void zap_leaf_stats(struct zap *zap, zap_leaf_t *l,
struct zap_stats *zs);
Expand Down
77 changes: 34 additions & 43 deletions module/zfs/zap_leaf.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -41,7 +41,8 @@
#include <sys/zap_leaf.h>
#include <sys/arc.h>

static uint16_t *zap_leaf_rehash_entry(zap_leaf_t *l, uint16_t entry);
static uint16_t *zap_leaf_rehash_entry(zap_leaf_t *l, struct zap_leaf_entry *le,
uint16_t entry);

#define CHAIN_END 0xffff /* end of the chunk chain */

Expand All @@ -52,16 +53,6 @@ static uint16_t *zap_leaf_rehash_entry(zap_leaf_t *l, uint16_t entry);

#define LEAF_HASH_ENTPTR(l, h) (&zap_leaf_phys(l)->l_hash[LEAF_HASH(l, h)])

static void
zap_memset(void *a, int c, size_t n)
{
char *cp = a;
char *cpend = cp + n;

while (cp < cpend)
*cp++ = c;
}

static void
stv(int len, void *addr, uint64_t value)
{
Expand All @@ -79,7 +70,7 @@ stv(int len, void *addr, uint64_t value)
*(uint64_t *)addr = value;
return;
default:
cmn_err(CE_PANIC, "bad int len %d", len);
PANIC("bad int len %d", len);
}
}

Expand All @@ -96,13 +87,13 @@ ldv(int len, const void *addr)
case 8:
return (*(uint64_t *)addr);
default:
cmn_err(CE_PANIC, "bad int len %d", len);
PANIC("bad int len %d", len);
}
return (0xFEEDFACEDEADBEEFULL);
}

void
zap_leaf_byteswap(zap_leaf_phys_t *buf, int size)
zap_leaf_byteswap(zap_leaf_phys_t *buf, size_t size)
{
zap_leaf_t l;
dmu_buf_t l_dbuf;
Expand All @@ -119,10 +110,10 @@ zap_leaf_byteswap(zap_leaf_phys_t *buf, int size)
buf->l_hdr.lh_prefix_len = BSWAP_16(buf->l_hdr.lh_prefix_len);
buf->l_hdr.lh_freelist = BSWAP_16(buf->l_hdr.lh_freelist);

for (int i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(&l); i++)
for (uint_t i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(&l); i++)
buf->l_hash[i] = BSWAP_16(buf->l_hash[i]);

for (int i = 0; i < ZAP_LEAF_NUMCHUNKS(&l); i++) {
for (uint_t i = 0; i < ZAP_LEAF_NUMCHUNKS(&l); i++) {
zap_leaf_chunk_t *lc = &ZAP_LEAF_CHUNK(&l, i);
struct zap_leaf_entry *le;

Expand Down Expand Up @@ -160,11 +151,11 @@ void
zap_leaf_init(zap_leaf_t *l, boolean_t sort)
{
l->l_bs = highbit64(l->l_dbuf->db_size) - 1;
zap_memset(&zap_leaf_phys(l)->l_hdr, 0,
memset(&zap_leaf_phys(l)->l_hdr, 0,
sizeof (struct zap_leaf_header));
zap_memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
2*ZAP_LEAF_HASH_NUMENTRIES(l));
for (int i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
for (uint_t i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
ZAP_LEAF_CHUNK(l, i).l_free.lf_type = ZAP_CHUNK_FREE;
ZAP_LEAF_CHUNK(l, i).l_free.lf_next = i+1;
}
Expand All @@ -185,7 +176,7 @@ zap_leaf_chunk_alloc(zap_leaf_t *l)
{
ASSERT(zap_leaf_phys(l)->l_hdr.lh_nfree > 0);

int chunk = zap_leaf_phys(l)->l_hdr.lh_freelist;
uint_t chunk = zap_leaf_phys(l)->l_hdr.lh_freelist;
ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
ASSERT3U(ZAP_LEAF_CHUNK(l, chunk).l_free.lf_type, ==, ZAP_CHUNK_FREE);

Expand Down Expand Up @@ -223,28 +214,29 @@ zap_leaf_array_create(zap_leaf_t *l, const char *buf,
{
uint16_t chunk_head;
uint16_t *chunkp = &chunk_head;
int byten = 0;
int byten = integer_size;
uint64_t value = 0;
int shift = (integer_size - 1) * 8;
int len = num_integers;

ASSERT3U(num_integers * integer_size, <=, ZAP_MAXVALUELEN);

if (len > 0)
value = ldv(integer_size, buf);
while (len > 0) {
uint16_t chunk = zap_leaf_chunk_alloc(l);
struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;

la->la_type = ZAP_CHUNK_ARRAY;
for (int i = 0; i < ZAP_LEAF_ARRAY_BYTES; i++) {
if (byten == 0)
value = ldv(integer_size, buf);
la->la_array[i] = value >> shift;
value <<= 8;
if (++byten == integer_size) {
byten = 0;
buf += integer_size;
if (--byten == 0) {
if (--len == 0)
break;
byten = integer_size;
buf += integer_size;
value = ldv(integer_size, buf);
}
}

Expand All @@ -264,7 +256,7 @@ zap_leaf_array_free(zap_leaf_t *l, uint16_t *chunkp)
*chunkp = CHAIN_END;

while (chunk != CHAIN_END) {
int nextchunk = ZAP_LEAF_CHUNK(l, chunk).l_array.la_next;
uint_t nextchunk = ZAP_LEAF_CHUNK(l, chunk).l_array.la_next;
ASSERT3U(ZAP_LEAF_CHUNK(l, chunk).l_array.la_type, ==,
ZAP_CHUNK_ARRAY);
zap_leaf_chunk_free(l, chunk);
Expand Down Expand Up @@ -333,7 +325,7 @@ zap_leaf_array_read(zap_leaf_t *l, uint16_t chunk,

static boolean_t
zap_leaf_array_match(zap_leaf_t *l, zap_name_t *zn,
int chunk, int array_numints)
uint_t chunk, int array_numints)
{
int bseen = 0;

Expand Down Expand Up @@ -562,7 +554,7 @@ zap_entry_create(zap_leaf_t *l, zap_name_t *zn, uint32_t cd,

uint64_t valuelen = integer_size * num_integers;

int numchunks = 1 + ZAP_LEAF_ARRAY_NCHUNKS(zn->zn_key_orig_numints *
uint_t numchunks = 1 + ZAP_LEAF_ARRAY_NCHUNKS(zn->zn_key_orig_numints *
zn->zn_key_intlen) + ZAP_LEAF_ARRAY_NCHUNKS(valuelen);
if (numchunks > ZAP_LEAF_NUMCHUNKS(l))
return (SET_ERROR(E2BIG));
Expand Down Expand Up @@ -624,7 +616,7 @@ zap_entry_create(zap_leaf_t *l, zap_name_t *zn, uint32_t cd,

/* link it into the hash chain */
/* XXX if we did the search above, we could just use that */
uint16_t *chunkp = zap_leaf_rehash_entry(l, chunk);
uint16_t *chunkp = zap_leaf_rehash_entry(l, le, chunk);

zap_leaf_phys(l)->l_hdr.lh_nentries++;

Expand Down Expand Up @@ -687,9 +679,8 @@ zap_entry_normalization_conflict(zap_entry_handle_t *zeh, zap_name_t *zn,
*/

static uint16_t *
zap_leaf_rehash_entry(zap_leaf_t *l, uint16_t entry)
zap_leaf_rehash_entry(zap_leaf_t *l, struct zap_leaf_entry *le, uint16_t entry)
{
struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, entry);
struct zap_leaf_entry *le2;
uint16_t *chunkp;

Expand Down Expand Up @@ -722,7 +713,7 @@ zap_leaf_transfer_array(zap_leaf_t *l, uint16_t chunk, zap_leaf_t *nl)
&ZAP_LEAF_CHUNK(nl, nchunk).l_array;
struct zap_leaf_array *la =
&ZAP_LEAF_CHUNK(l, chunk).l_array;
int nextchunk = la->la_next;
uint_t nextchunk = la->la_next;

ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
ASSERT3U(nchunk, <, ZAP_LEAF_NUMCHUNKS(l));
Expand All @@ -739,7 +730,7 @@ zap_leaf_transfer_array(zap_leaf_t *l, uint16_t chunk, zap_leaf_t *nl)
}

static void
zap_leaf_transfer_entry(zap_leaf_t *l, int entry, zap_leaf_t *nl)
zap_leaf_transfer_entry(zap_leaf_t *l, uint_t entry, zap_leaf_t *nl)
{
struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, entry);
ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
Expand All @@ -748,7 +739,7 @@ zap_leaf_transfer_entry(zap_leaf_t *l, int entry, zap_leaf_t *nl)
struct zap_leaf_entry *nle = ZAP_LEAF_ENTRY(nl, chunk);
*nle = *le; /* structure assignment */

(void) zap_leaf_rehash_entry(nl, chunk);
(void) zap_leaf_rehash_entry(nl, nle, chunk);

nle->le_name_chunk = zap_leaf_transfer_array(l, le->le_name_chunk, nl);
nle->le_value_chunk =
Expand All @@ -766,7 +757,7 @@ zap_leaf_transfer_entry(zap_leaf_t *l, int entry, zap_leaf_t *nl)
void
zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort)
{
int bit = 64 - 1 - zap_leaf_phys(l)->l_hdr.lh_prefix_len;
uint_t bit = 64 - 1 - zap_leaf_phys(l)->l_hdr.lh_prefix_len;

/* set new prefix and prefix_len */
zap_leaf_phys(l)->l_hdr.lh_prefix <<= 1;
Expand All @@ -777,7 +768,7 @@ zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort)
zap_leaf_phys(l)->l_hdr.lh_prefix_len;

/* break existing hash chains */
zap_memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
2*ZAP_LEAF_HASH_NUMENTRIES(l));

if (sort)
Expand All @@ -792,22 +783,22 @@ zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort)
* but this accesses memory more sequentially, and when we're
* called, the block is usually pretty full.
*/
for (int i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
for (uint_t i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, i);
if (le->le_type != ZAP_CHUNK_ENTRY)
continue;

if (le->le_hash & (1ULL << bit))
zap_leaf_transfer_entry(l, i, nl);
else
(void) zap_leaf_rehash_entry(l, i);
(void) zap_leaf_rehash_entry(l, le, i);
}
}

void
zap_leaf_stats(zap_t *zap, zap_leaf_t *l, zap_stats_t *zs)
{
int n = zap_f_phys(zap)->zap_ptrtbl.zt_shift -
uint_t n = zap_f_phys(zap)->zap_ptrtbl.zt_shift -
zap_leaf_phys(l)->l_hdr.lh_prefix_len;
n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
zs->zs_leafs_with_2n_pointers[n]++;
Expand All @@ -823,9 +814,9 @@ zap_leaf_stats(zap_t *zap, zap_leaf_t *l, zap_stats_t *zs)
n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
zs->zs_blocks_n_tenths_full[n]++;

for (int i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(l); i++) {
int nentries = 0;
int chunk = zap_leaf_phys(l)->l_hash[i];
for (uint_t i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(l); i++) {
uint_t nentries = 0;
uint_t chunk = zap_leaf_phys(l)->l_hash[i];

while (chunk != CHAIN_END) {
struct zap_leaf_entry *le =
Expand Down

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