e600f9aebb
This commit updates default memory allocations size used with MEM_ROOT objects to minimize the number of calls to malloc(). Changes: - Updated MEM_ROOT block sizes in sql_const.h - Updated MALLOC_OVERHEAD to also take into account the extra memory allocated by my_malloc() - Updated init_alloc_root() to only take MALLOC_OVERHEAD into account as buffer size, not MALLOC_OVERHEAD + sizeof(USED_MEM). - Reset mem_root->first_block_usage if and only if first block was used. - Increase MEM_ROOT buffers sized used by my_load_defaults, plugin_init, Create_tmp_table, allocate_table_share, TABLE and TABLE_SHARE. This decreases number of malloc calls during queries. - Use a small buffer for THD->main_mem_root in THD::THD. This avoids multiple malloc() call for new connections. I tried the above changes on a complex select query with 12 tables. The following shows the number of extra allocations that where used to increase the size of the MEM_ROOT buffers. Original code: - Connection to MariaDB: 9 allocations - First query run: 146 allocations - Second query run: 24 allocations Max memory allocated for thd when using with heap table: 61,262,408 Max memory allocated for thd when using Aria tmp table: 419,464 After changes: Connection to MariaDB: 0 allocations - First run: 25 allocations - Second run: 7 allocations Max memory allocated for thd when using with heap table: 61,347,424 Max memory allocated for thd when using Aria table: 529,168 The new code uses slightly more memory, but avoids memory fragmentation and is slightly faster thanks to much fewer calls to malloc(). Reviewed-by: Sergei Golubchik <serg@mariadb.org> |
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| BUILD | ||
| client | ||
| cmake | ||
| dbug | ||
| debian | ||
| Docs | ||
| extra | ||
| include | ||
| libmariadb@3f2196d84e | ||
| libmysqld | ||
| libservices | ||
| man | ||
| mysql-test | ||
| mysys | ||
| mysys_ssl | ||
| plugin | ||
| randgen/conf | ||
| scripts | ||
| sql | ||
| sql-bench | ||
| sql-common | ||
| storage | ||
| strings | ||
| support-files | ||
| tests | ||
| tpool | ||
| unittest | ||
| vio | ||
| win | ||
| wsrep-lib@70cd967f5e | ||
| zlib | ||
| .clang-format | ||
| .gitattributes | ||
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| .gitlab-ci.yml | ||
| .gitmodules | ||
| appveyor.yml | ||
| BUILD-CMAKE | ||
| CMakeLists.txt | ||
| config.h.cmake | ||
| configure.cmake | ||
| CONTRIBUTING.md | ||
| COPYING | ||
| CREDITS | ||
| INSTALL-SOURCE | ||
| INSTALL-WIN-SOURCE | ||
| KNOWN_BUGS.txt | ||
| README.md | ||
| THIRDPARTY | ||
| VERSION | ||
Code status:
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MariaDB: The innovative open source database
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