Hi!
>>>>> "MARK" == MARK CALLAGHAN <mdcallag@stripped> writes:
MARK> On Thu, Jun 4, 2009 at 2:24 PM, Michael Widenius <monty@stripped>
> wrote:
>>
>> hi!
>>
MARK> howdy
MARK> I have never had any luck using gprof on multi-threaded servers. If
MARK> you use Linux, then oProfile works great for flat profiles and Google
MARK> perftools works great for hierarchical profiles. But to use perftools,
MARK> you need to make some changes to the server.
>>
>> gprof should work fine with MySQL.
>> At least I have in the past run the sql-bench benchmark with gprof
>> with good results.
>>
>> In theory, to compile with gprof on intel/amd you should just have to
>> build with:
>> ./BUILD/compile-pentium64-gprof
MARK> The output for hierarchical profiling looks broken. I don't need flat
MARK> profiles from gprof as oprofile is much better for that. Here is an
MARK> example with functions from the HEAP, MyISAM and Innobase engines
MARK> mixed together. If you google for 'gprof multithread' or 'gprof
MARK> multithreaded' you will find details of problems that existed this
MARK> decade. I don't know if the referenced problems have been fixed.
MARK> So, it still doesn't work for me. Can anyone tell me how to fix it?
MARK> The output is from 'mysql-test-run --gprof innodb'. I compiled using
MARK> BUILD/compile-pentium-64-gprof after removing '$debug_configs'
I haven't use gprof with mysql-test-run, only with run-all-tests,
which is mainly a single threaded tests (but useful to find
bottlenecks in normal code).
MARK> 802 mysql_insert(THD*,
MARK> TABLE_LIST*, List<Item>&, List<List<Item> >&,
> List<Item>&,
MARK> List<Item>&, enum_duplicates, bool) <cycle 6> [218]
MARK> 571638
MARK> select_insert::send_data(List<Item>&) <cycle 6> [113]
MARK> [6] 43.4 0.04 2.95 572440 write_record(THD*,
MARK> st_table*, st_copy_info*) <cycle 6> [6]
MARK> 0.02 2.93 554320/555551
MARK> ha_innobase::write_row(char*) [7]
MARK> 0.00 0.00 18115/411178 mi_write [138]
MARK> 0.00 0.00 21/42
MARK> handler::print_error(int, int) [544]
MARK> 0.00 0.00 18115/411168
MARK> ha_myisam::write_row(char*) [390]
MARK> 0.00 0.00 8/29585
Sorry, but the text is so mangled that I can't easily read it.
(Haven't read gprof for 2 years now, and I forgot the exact format to
be able to comment)
If you could point out one case that is wrong with the output I may be
able to help you.
Regards,
Monty
