Hi Kristian
On 04/30/2014 02:11 PM, Kristian Nielsen wrote:
Vangelis Katsikaros vkatsika...@yahoo.gr writes:
What do you mean with the phrase [code|server] falls over?
I am refering to a common phenomenon in high-concurrency benchmarks. See for
example the graph in this email:
Vangelis Katsikaros vkatsika...@yahoo.gr writes:
What do you mean with the phrase [code|server] falls over?
I am refering to a common phenomenon in high-concurrency benchmarks. See for
example the graph in this email:
https://lists.launchpad.net/maria-developers/msg06799.html
Hi Kristian
On 04/22/2014 04:11 PM, Kristian Nielsen wrote:
As a side effect, if we improve the code performance of a single thread, we
effectively increase the concurrency in the critical spots - threads spend
less time executing the real code, hence more time in concurrency
bottlenecks. The
Kristian Nielsen kniel...@knielsen-hq.org writes:
Axel Schwenke a...@askmonty.org writes:
Benchmark 1 is good old sysbench OLTP. I tested 10.0.7 vs. 10.0.7-pgo. With
low concurrency there is about 10% win by PGO; however this is completely
reversed at higher concurrency by mutex contention
Kristian Nielsen wrote:
I implemented a simple program to generate some profile load:
https://github.com/knielsen/gen_profile_load
I propose the following change to make it work with MariaDB releases before
10.0.4 (and MySQL) that lack the SHUTDOWN statement:
--- gen_profile_load.c.orig
Axel Schwenke a...@askmonty.org writes:
I propose the following change to make it work with MariaDB releases before
10.0.4 (and MySQL) that lack the SHUTDOWN statement:
Nice, thanks Axel!
- Kristian.
___
Mailing list:
Sergey Vojtovich s...@mariadb.org writes:
Still a questions mostly to educate myself. According to proc mysqld
executable
size is something like:
VmExe: 12228 kB
VmLib:6272 kB
I assume the above refers to overall instructions. Level 1 instruction cache
size is like
Hi Kristian,
Kristian Nielsen wrote:
I have been analysing CPU bottlenecks in single-threaded sysbench read-only
load. I found that icache misses is the main bottleneck, and that
profile-guided compiler optimisation (PGO) with GCC gives a large speedup, 25%
or more.
(More details in my
Axel Schwenke a...@askmonty.org writes:
Wow. 25% is a lot. Have you also tried compiling MySQL 5.6 with PGO?
No.
Because if that gets the same improvement, we haven't won anything in the
comparison.
On the contrary, if the same works for MySQL 5.6 (and it seems likely it
will), then we have
Hi Kristian,
just out of curiosity: is it possible to find out which functions cause highest
amount of icache misses? Can it have anything to do with branch misprediction?
Regards,
Sergey
On Fri, Jan 24, 2014 at 03:51:25PM +0100, Kristian Nielsen wrote:
I have been analysing CPU bottlenecks in
Sergey Vojtovich s...@mariadb.org writes:
just out of curiosity: is it possible to find out which functions cause
highest
amount of icache misses?
Yes, see the second post, the profiles marked Icache misses (ICACHE.MISSES),
before PGO and Icache misses (ICACHE.MISSES), after PGO. These are
I have been analysing CPU bottlenecks in single-threaded sysbench read-only
load. I found that icache misses is the main bottleneck, and that
profile-guided compiler optimisation (PGO) with GCC gives a large speedup, 25%
or more.
(More details in my blog posts:
12 matches
Mail list logo
