Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit9fab40a

Browse files
committed
Use the new "Slab" context for some allocations in reorderbuffer.h.
Note that this change alone does not yet fully address the performanceproblems triggering this work, a large portion of the slowdown istriggered by the tuple allocator, which isn't converted to the newallocator. It would be possible to do so, but using evenly sizedobjects, like both the current implementation in reorderbuffer.c andslab.c, wastes a fair amount of memory. A later patch by Tomas willintroduce a better approach.Author: Tomas VondraReviewed-By: Andres FreundDiscussion:https://postgr.es/m/d15dff83-0b37-28ed-0809-95a5cc7292ad@2ndquadrant.com
1 parent58b25e9 commit9fab40a

File tree

2 files changed

+22
-66
lines changed

2 files changed

+22
-66
lines changed

‎src/backend/replication/logical/reorderbuffer.c

Lines changed: 16 additions & 58 deletions
Original file line numberDiff line numberDiff line change
@@ -156,10 +156,7 @@ static const Size max_changes_in_memory = 4096;
156156
* major bottleneck, especially when spilling to disk while decoding batch
157157
* workloads.
158158
*/
159-
staticconstSizemax_cached_changes=4096*2;
160159
staticconstSizemax_cached_tuplebufs=4096*2;/* ~8MB */
161-
staticconstSizemax_cached_transactions=512;
162-
163160

164161
/* ---------------------------------------
165162
* primary reorderbuffer support routines
@@ -241,6 +238,16 @@ ReorderBufferAllocate(void)
241238

242239
buffer->context=new_ctx;
243240

241+
buffer->change_context=SlabContextCreate(new_ctx,
242+
"Change",
243+
SLAB_DEFAULT_BLOCK_SIZE,
244+
sizeof(ReorderBufferChange));
245+
246+
buffer->txn_context=SlabContextCreate(new_ctx,
247+
"TXN",
248+
SLAB_DEFAULT_BLOCK_SIZE,
249+
sizeof(ReorderBufferTXN));
250+
244251
hash_ctl.keysize=sizeof(TransactionId);
245252
hash_ctl.entrysize=sizeof(ReorderBufferTXNByIdEnt);
246253
hash_ctl.hcxt=buffer->context;
@@ -251,8 +258,6 @@ ReorderBufferAllocate(void)
251258
buffer->by_txn_last_xid=InvalidTransactionId;
252259
buffer->by_txn_last_txn=NULL;
253260

254-
buffer->nr_cached_transactions=0;
255-
buffer->nr_cached_changes=0;
256261
buffer->nr_cached_tuplebufs=0;
257262

258263
buffer->outbuf=NULL;
@@ -261,8 +266,6 @@ ReorderBufferAllocate(void)
261266
buffer->current_restart_decoding_lsn=InvalidXLogRecPtr;
262267

263268
dlist_init(&buffer->toplevel_by_lsn);
264-
dlist_init(&buffer->cached_transactions);
265-
dlist_init(&buffer->cached_changes);
266269
slist_init(&buffer->cached_tuplebufs);
267270

268271
returnbuffer;
@@ -291,19 +294,8 @@ ReorderBufferGetTXN(ReorderBuffer *rb)
291294
{
292295
ReorderBufferTXN*txn;
293296

294-
/* check the slab cache */
295-
if (rb->nr_cached_transactions>0)
296-
{
297-
rb->nr_cached_transactions--;
298-
txn= (ReorderBufferTXN*)
299-
dlist_container(ReorderBufferTXN,node,
300-
dlist_pop_head_node(&rb->cached_transactions));
301-
}
302-
else
303-
{
304-
txn= (ReorderBufferTXN*)
305-
MemoryContextAlloc(rb->context,sizeof(ReorderBufferTXN));
306-
}
297+
txn= (ReorderBufferTXN*)
298+
MemoryContextAlloc(rb->txn_context,sizeof(ReorderBufferTXN));
307299

308300
memset(txn,0,sizeof(ReorderBufferTXN));
309301

@@ -344,18 +336,7 @@ ReorderBufferReturnTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
344336
txn->invalidations=NULL;
345337
}
346338

347-
/* check whether to put into the slab cache */
348-
if (rb->nr_cached_transactions<max_cached_transactions)
349-
{
350-
rb->nr_cached_transactions++;
351-
dlist_push_head(&rb->cached_transactions,&txn->node);
352-
VALGRIND_MAKE_MEM_UNDEFINED(txn,sizeof(ReorderBufferTXN));
353-
VALGRIND_MAKE_MEM_DEFINED(&txn->node,sizeof(txn->node));
354-
}
355-
else
356-
{
357-
pfree(txn);
358-
}
339+
pfree(txn);
359340
}
360341

361342
/*
@@ -366,19 +347,8 @@ ReorderBufferGetChange(ReorderBuffer *rb)
366347
{
367348
ReorderBufferChange*change;
368349

369-
/* check the slab cache */
370-
if (rb->nr_cached_changes)
371-
{
372-
rb->nr_cached_changes--;
373-
change= (ReorderBufferChange*)
374-
dlist_container(ReorderBufferChange,node,
375-
dlist_pop_head_node(&rb->cached_changes));
376-
}
377-
else
378-
{
379-
change= (ReorderBufferChange*)
380-
MemoryContextAlloc(rb->context,sizeof(ReorderBufferChange));
381-
}
350+
change= (ReorderBufferChange*)
351+
MemoryContextAlloc(rb->change_context,sizeof(ReorderBufferChange));
382352

383353
memset(change,0,sizeof(ReorderBufferChange));
384354
returnchange;
@@ -434,21 +404,9 @@ ReorderBufferReturnChange(ReorderBuffer *rb, ReorderBufferChange *change)
434404
break;
435405
}
436406

437-
/* check whether to put into the slab cache */
438-
if (rb->nr_cached_changes<max_cached_changes)
439-
{
440-
rb->nr_cached_changes++;
441-
dlist_push_head(&rb->cached_changes,&change->node);
442-
VALGRIND_MAKE_MEM_UNDEFINED(change,sizeof(ReorderBufferChange));
443-
VALGRIND_MAKE_MEM_DEFINED(&change->node,sizeof(change->node));
444-
}
445-
else
446-
{
447-
pfree(change);
448-
}
407+
pfree(change);
449408
}
450409

451-
452410
/*
453411
* Get an unused, possibly preallocated, ReorderBufferTupleBuf fitting at
454412
* least a tuple of size tuple_len (excluding header overhead).

‎src/include/replication/reorderbuffer.h

Lines changed: 6 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -330,6 +330,12 @@ struct ReorderBuffer
330330
*/
331331
MemoryContextcontext;
332332

333+
/*
334+
* Memory contexts for specific types objects
335+
*/
336+
MemoryContextchange_context;
337+
MemoryContexttxn_context;
338+
333339
/*
334340
* Data structure slab cache.
335341
*
@@ -340,14 +346,6 @@ struct ReorderBuffer
340346
* on top of reorderbuffer.c
341347
*/
342348

343-
/* cached ReorderBufferTXNs */
344-
dlist_headcached_transactions;
345-
Sizenr_cached_transactions;
346-
347-
/* cached ReorderBufferChanges */
348-
dlist_headcached_changes;
349-
Sizenr_cached_changes;
350-
351349
/* cached ReorderBufferTupleBufs */
352350
slist_headcached_tuplebufs;
353351
Sizenr_cached_tuplebufs;

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp