← Back to team overview

maria-discuss team mailing list archive

Re: MariaDB and TLB misses / Large Pages


Am 21.10.2016 um 18:16 schrieb Guillaume Lefranc:
The MySQL Manual gives good pointers about TLB settings that should
apply to MariaDB as well:

we had that long in use on MySQL adn with unchanged settings MariaDB logged that it failed and it is falling back to conventional allocation

besides that *this* way of large pages (/proc/sys/vm/hugetlb_shm_group) is horrible for a ton of reasons

* more than one application - they all need to share a group
* very difficult to calculate (/proc/sys/vm/nr_hugepages)
* if it's too low and dataset grosws it will fail later silently
* if it's too large you waste memory and end in OOM at worst

that's really not a considerable solution in 2016

Le jeu. 20 oct. 2016 à 20:33, J. Cassidy <sean@xxxxxxxxxxxx
<mailto:sean@xxxxxxxxxxxx>> a écrit :

    Hello all,

    is there a reliable cookbook / checklist to implement Large Tables
    on a SuSE SLES 12 SP1 Linux distribution?

    I find there there is a lot of old/inaccurate/dodgy information on
    my search machine travels.

    The test setup is as follows-

    Everything enabled for Large Pages as per various online Fora.

    128GB RAM

    72GB InnoDB buffer size, eight instances.

    MariaDB is DB is defined in a 52GB RAM disk. (This is a test to tie
    down TLB and Lx cache misses and high CPU next activity)

    Any pointers/hints most welcome.