mirror/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-04-08 00:05:34 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions1

MDEV-20302 Server hangs upon concurrent SELECT from partitioned S3

Browse source 
Second attempt to fix same bug:

Use the same queue for all READ operations.
Release queues for all used pages.

This fixes a hang in the s3.alter2 test case
This commit is contained in:
Oleksandr Byelkin 2020-06-18 13:21:29 +02:00 • committed by Monty
parent 60f08dd555
commit 4243785f28
1 changed files with 18 additions and 10 deletions

28
storage/maria/ma_pagecache.c
View file

@ -130,8 +130,7 @@ my_bool my_disable_flush_pagecache_blocks= 0;
#define COND_FOR_REQUESTED 0 /* queue of thread waiting for read operation */
#define COND_FOR_SAVED 1 /* queue of thread waiting for flush */
#define COND_FOR_WRLOCK 2 /* queue of write lock */
#define COND_FOR_BIG_BLOCK 3 /* queue of waiting for big block read */
#define COND_SIZE 4 /* number of COND_* queues */
#define COND_SIZE 3 /* number of COND_* queues */
typedef mysql_cond_t KEYCACHE_CONDVAR;
@ -2830,7 +2829,7 @@ static void read_big_block(PAGECACHE *pagecache,
*/
thread= my_thread_var;
/* Put the request into a queue and wait until it can be processed */
wqueue_add_to_queue(&block_to_read->wqueue[COND_FOR_BIG_BLOCK], thread);
wqueue_add_to_queue(&block_to_read->wqueue[COND_FOR_REQUESTED], thread);
do
{
DBUG_PRINT("wait",
@ -2840,7 +2839,7 @@ static void read_big_block(PAGECACHE *pagecache,
&pagecache->cache_lock);
}
while (thread->next);
// page shoud be read by other thread
// page should be read by other thread
DBUG_ASSERT(block->status & PCBLOCK_READ ||
block->status & PCBLOCK_ERROR);
DBUG_ASSERT(block->status & PCBLOCK_BIG_READ);
@ -2900,7 +2899,12 @@ static void read_big_block(PAGECACHE *pagecache,
block_to_read->status|= PCBLOCK_READ;
}
else
{
DBUG_ASSERT(block_to_read->status & PCBLOCK_READ);
}
/* Signal that all pending requests for this page now can be processed */
if (block_to_read->wqueue[COND_FOR_REQUESTED].last_thread)
wqueue_release_queue(&block_to_read->wqueue[COND_FOR_REQUESTED]);
/* Copy the rest of the pages */
for (offset= pagecache->block_size, page= page_to_read + 1;
@ -2925,13 +2929,13 @@ static void read_big_block(PAGECACHE *pagecache,
/*
We can not get this page easy.
Maybe we will be lucky with other pages,
also among other pages can be page which wated by other thread
also among other pages can be page which waited by other thread
*/
continue;
}
DBUG_ASSERT(bl == bl->hash_link->block);
if ((bl->status & PCBLOCK_ERROR) == 0 &&
(page_st == PAGE_TO_BE_READ || // page shoud be read
(page_st == PAGE_TO_BE_READ || // page should be read
(page_st == PAGE_WAIT_TO_BE_READ &&
(bl->status & PCBLOCK_BIG_READ)))) // or page waited by other thread
{
@ -2940,6 +2944,9 @@ static void read_big_block(PAGECACHE *pagecache,
}
remove_reader(bl);
unreg_request(pagecache, bl, 1);
/* Signal that all pending requests for this page now can be processed */
if (bl->wqueue[COND_FOR_REQUESTED].last_thread)
wqueue_release_queue(&bl->wqueue[COND_FOR_REQUESTED]);
}
}
if (page < our_page)
@ -2961,8 +2968,6 @@ end:
remove_reader(block_to_read);
unreg_request(pagecache, block_to_read, 1);
}
if (block->wqueue[COND_FOR_BIG_BLOCK].last_thread)
wqueue_release_queue(&block->wqueue[COND_FOR_BIG_BLOCK]);
/* Signal that all pending requests for this page now can be processed */
if (block->wqueue[COND_FOR_REQUESTED].last_thread)
wqueue_release_queue(&block->wqueue[COND_FOR_REQUESTED]);
@ -2995,13 +3000,13 @@ error:
/*
We can not get this page easy.
Maybe we will be lucky with other pages,
also among other pages can be page which wated by other thread
also among other pages can be page which waited by other thread
*/
continue;
}
DBUG_ASSERT(bl == bl->hash_link->block);
if ((bl->status & PCBLOCK_ERROR) == 0 &&
(page_st == PAGE_TO_BE_READ || // page shoud be read
(page_st == PAGE_TO_BE_READ || // page should be read
(page_st == PAGE_WAIT_TO_BE_READ &&
(bl->status & PCBLOCK_BIG_READ)))) // or page waited by other thread
{
@ -3010,6 +3015,9 @@ error:
}
remove_reader(bl);
unreg_request(pagecache, bl, 1);
/* Signal that all pending requests for this page now can be processed */
if (bl->wqueue[COND_FOR_REQUESTED].last_thread)
wqueue_release_queue(&bl->wqueue[COND_FOR_REQUESTED]);
}
}
goto end;