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Commit b556ef1f authored by Rusty Russell's avatar Rusty Russell
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tdb2: speed up transaction code by making page size a constant. 

Turning getpagesize() into a constant 4096 really helps gcc optimize, and
not just on 64 bit.

Here are the results of running "tools/speed --transaction --no-sync 2000000":

i386 with gcc 4.4.5:
Before:
	$ ./speed --transaction --no-sync 2000000
	Adding 2000000 records:  1195 ns (93594224 bytes)
	Finding 2000000 records:  719 ns (93594224 bytes)
	Missing 2000000 records:  429 ns (93594224 bytes)
	Traversing 2000000 records:  523 ns (93594224 bytes)
	Deleting 2000000 records:  901 ns (93594224 bytes)
	Re-adding 2000000 records:  1032 ns (93594224 bytes)
	Appending 2000000 records:  1711 ns (182801232 bytes)
	Churning 2000000 records:  3233 ns (182801232 bytes)

After:
	Adding 2000000 records:  868 ns (93594224 bytes)
	Finding 2000000 records:  569 ns (93594224 bytes)
	Missing 2000000 records:  369 ns (93594224 bytes)
	Traversing 2000000 records:  406 ns (93594224 bytes)
	Deleting 2000000 records:  674 ns (93594224 bytes)
	Re-adding 2000000 records:  730 ns (93594224 bytes)
	Appending 2000000 records:  1144 ns (182801232 bytes)
	Churning 2000000 records:  2085 ns (182801232 bytes)

Here's the effect (average of 10) on x8664 with gcc 4.1.2, with an earlier
tree and 1000000:
	Before:
		Adding 830.1ns
		Finding 428.3ns
		Missing 250.3ns
		Traversing 387.4ns
		Deleting 588.8ns
		Re-adding 737.2ns
		Appending 1141.4ns
		Churning 1792ns

	After:
		Adding 562.8ns
		Finding 362.1ns
		Missing 226.4ns
		Traversing 276.5ns
		Deleting 426.7ns
		Re-adding 489.8ns
		Appending 736.4ns
		Churning 1112.7ns
parent 1444b09c
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Inline Side-by-side
Showing with 33 additions and 31 deletions
ccan/tdb2/transaction.c
View file @ b556ef1f
......@@ -120,6 +120,8 @@ struct tdb_transaction {
tdb_len_t old_map_size;
};
/* This doesn't really need to be pagesize, but we use it for similar reasons. */
#define PAGESIZE 4096
/*
read while in a transaction. We need to check first if the data is in our list
......@@ -132,8 +134,8 @@ static enum TDB_ERROR transaction_read(struct tdb_context *tdb, tdb_off_t off,
enum TDB_ERROR ecode;
/* break it down into block sized ops */
while (len + (off % getpagesize()) > getpagesize()) {
tdb_len_t len2 = getpagesize() - (off % getpagesize());
while (len + (off % PAGESIZE) > PAGESIZE) {
tdb_len_t len2 = PAGESIZE - (off % PAGESIZE);
ecode = transaction_read(tdb, off, buf, len2);
if (ecode != TDB_SUCCESS) {
return ecode;
......@@ -147,7 +149,7 @@ static enum TDB_ERROR transaction_read(struct tdb_context *tdb, tdb_off_t off,
return TDB_SUCCESS;
}
blk = off / getpagesize();
blk = off / PAGESIZE;
/* see if we have it in the block list */
if (tdb->transaction->num_blocks <= blk ||
......@@ -169,7 +171,7 @@ static enum TDB_ERROR transaction_read(struct tdb_context *tdb, tdb_off_t off,
}
/* now copy it out of this block */
memcpy(buf, tdb->transaction->blocks[blk] + (off % getpagesize()), len);
memcpy(buf, tdb->transaction->blocks[blk] + (off % PAGESIZE), len);
return TDB_SUCCESS;
fail:
......@@ -198,8 +200,8 @@ static enum TDB_ERROR transaction_write(struct tdb_context *tdb, tdb_off_t off,
}
/* break it up into block sized chunks */
while (len + (off % getpagesize()) > getpagesize()) {
tdb_len_t len2 = getpagesize() - (off % getpagesize());
while (len + (off % PAGESIZE) > PAGESIZE) {
tdb_len_t len2 = PAGESIZE - (off % PAGESIZE);
ecode = transaction_write(tdb, off, buf, len2);
if (ecode != TDB_SUCCESS) {
return -1;
......@@ -215,8 +217,8 @@ static enum TDB_ERROR transaction_write(struct tdb_context *tdb, tdb_off_t off,
return TDB_SUCCESS;
}
blk = off / getpagesize();
off = off % getpagesize();
blk = off / PAGESIZE;
off = off % PAGESIZE;
if (tdb->transaction->num_blocks <= blk) {
uint8_t **new_blocks;
......@@ -244,20 +246,20 @@ static enum TDB_ERROR transaction_write(struct tdb_context *tdb, tdb_off_t off,
/* allocate and fill a block? */
if (tdb->transaction->blocks[blk] == NULL) {
tdb->transaction->blocks[blk] = (uint8_t *)calloc(getpagesize(), 1);
tdb->transaction->blocks[blk] = (uint8_t *)calloc(PAGESIZE, 1);
if (tdb->transaction->blocks[blk] == NULL) {
ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
"transaction_write:"
" failed to allocate");
goto fail;
}
if (tdb->transaction->old_map_size > blk * getpagesize()) {
tdb_len_t len2 = getpagesize();
if (len2 + (blk * getpagesize()) > tdb->transaction->old_map_size) {
len2 = tdb->transaction->old_map_size - (blk * getpagesize());
if (tdb->transaction->old_map_size > blk * PAGESIZE) {
tdb_len_t len2 = PAGESIZE;
if (len2 + (blk * PAGESIZE) > tdb->transaction->old_map_size) {
len2 = tdb->transaction->old_map_size - (blk * PAGESIZE);
}
ecode = tdb->transaction->io_methods->tread(tdb,
blk * getpagesize(),
blk * PAGESIZE,
tdb->transaction->blocks[blk],
len2);
if (ecode != TDB_SUCCESS) {
......@@ -306,8 +308,8 @@ static void transaction_write_existing(struct tdb_context *tdb, tdb_off_t off,
size_t blk;
/* break it up into block sized chunks */
while (len + (off % getpagesize()) > getpagesize()) {
tdb_len_t len2 = getpagesize() - (off % getpagesize());
while (len + (off % PAGESIZE) > PAGESIZE) {
tdb_len_t len2 = PAGESIZE - (off % PAGESIZE);
transaction_write_existing(tdb, off, buf, len2);
len -= len2;
off += len2;
......@@ -320,8 +322,8 @@ static void transaction_write_existing(struct tdb_context *tdb, tdb_off_t off,
return;
}
blk = off / getpagesize();
off = off % getpagesize();
blk = off / PAGESIZE;
off = off % PAGESIZE;
if (tdb->transaction->num_blocks <= blk ||
tdb->transaction->blocks[blk] == NULL) {
......@@ -379,10 +381,10 @@ static enum TDB_ERROR transaction_expand_file(struct tdb_context *tdb,
static void *transaction_direct(struct tdb_context *tdb, tdb_off_t off,
size_t len, bool write_mode)
{
size_t blk = off / getpagesize(), end_blk;
size_t blk = off / PAGESIZE, end_blk;
/* This is wrong for zero-length blocks, but will fail gracefully */
end_blk = (off + len - 1) / getpagesize();
end_blk = (off + len - 1) / PAGESIZE;
/* Can only do direct if in single block and we've already copied. */
if (write_mode) {
......@@ -392,14 +394,14 @@ static void *transaction_direct(struct tdb_context *tdb, tdb_off_t off,
return NULL;
if (tdb->transaction->blocks[blk] == NULL)
return NULL;
return tdb->transaction->blocks[blk] + off % getpagesize();
return tdb->transaction->blocks[blk] + off % PAGESIZE;
}
/* Single which we have copied? */
if (blk == end_blk
&& blk < tdb->transaction->num_blocks
&& tdb->transaction->blocks[blk])
return tdb->transaction->blocks[blk] + off % getpagesize();
return tdb->transaction->blocks[blk] + off % PAGESIZE;
/* Otherwise must be all not copied. */
while (blk <= end_blk) {
......@@ -437,7 +439,7 @@ static enum TDB_ERROR transaction_sync(struct tdb_context *tdb,
}
#ifdef MS_SYNC
if (tdb->file->map_ptr) {
tdb_off_t moffset = offset & ~(getpagesize()-1);
tdb_off_t moffset = offset & ~(PAGESIZE-1);
if (msync(moffset + (char *)tdb->file->map_ptr,
length + (offset - moffset), MS_SYNC) != 0) {
return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
......@@ -611,7 +613,7 @@ static tdb_len_t tdb_recovery_size(struct tdb_context *tdb)
recovery_size = sizeof(tdb_len_t);
for (i=0;i<tdb->transaction->num_blocks;i++) {
if (i * getpagesize() >= tdb->transaction->old_map_size) {
if (i * PAGESIZE >= tdb->transaction->old_map_size) {
break;
}
if (tdb->transaction->blocks[i] == NULL) {
......@@ -621,7 +623,7 @@ static tdb_len_t tdb_recovery_size(struct tdb_context *tdb)
if (i == tdb->transaction->num_blocks-1) {
recovery_size += tdb->transaction->last_block_size;
} else {
recovery_size += getpagesize();
recovery_size += PAGESIZE;
}
}
......@@ -696,8 +698,8 @@ static enum TDB_ERROR tdb_recovery_allocate(struct tdb_context *tdb,
/* round up to a multiple of page size */
*recovery_max_size
= (((sizeof(rec) + *recovery_size) + getpagesize()-1)
& ~(getpagesize()-1))
= (((sizeof(rec) + *recovery_size) + PAGESIZE-1)
& ~(PAGESIZE-1))
- sizeof(rec);
*recovery_offset = tdb->file->map_size;
recovery_head = *recovery_offset;
......@@ -798,8 +800,8 @@ static enum TDB_ERROR transaction_setup_recovery(struct tdb_context *tdb,
continue;
}
offset = i * getpagesize();
length = getpagesize();
offset = i * PAGESIZE;
length = PAGESIZE;
if (i == tdb->transaction->num_blocks-1) {
length = tdb->transaction->last_block_size;
}
......@@ -1029,8 +1031,8 @@ enum TDB_ERROR tdb_transaction_commit(struct tdb_context *tdb)
continue;
}
offset = i * getpagesize();
length = getpagesize();
offset = i * PAGESIZE;
length = PAGESIZE;
if (i == tdb->transaction->num_blocks-1) {
length = tdb->transaction->last_block_size;
}
......
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