sslug-teknik team mailing list archive

[dnj@xxxxxxxx (Dennis Jørgensen)]

Morten Sylvest Olsen <mso@xxxxxxxxxxxxxxxxxxx> writes:

> Peter Makholm wrote:

>> Og OOM-killeren er netop en af de ubehaglige ting ved linux'
>> VM. Det
>> burde være muligt at tilvælge en mere konservativ VM som kunne
>> garanterer at en process have adgang til hukommelse når den først
>> havde fået det tildelt.
>
> echo "0" >/proc/sys/vm/overcommit_memory
>
> burde vel gøre tricket?

Det er 1 der slår overcommit fra, selvom det er noget bagvendt.

Fra
kernel-doc-2.6.8/Documentation/vm/overcommit-accounting:



The Linux kernel supports three overcommit handling modes

0       -       Heuristic overcommit handling. Obvious overcommits of
                address space are refused. Used for a typical system. It
                ensures a seriously wild allocation fails while allowing
                overcommit to reduce swap usage.  root is allowed to
                allocate slighly more memory in this mode. This is the
                default.

1       -       No overcommit handling. Appropriate for some scientific
                applications.

2       -       (NEW) strict overcommit. The total address space commit
                for the system is not permitted to exceed swap + a
                configurable percentage (default is 50) of physical RAM.
                Depending on the percentage you use, in most situations
                this means a process will not be killed while accessing
                pages but will receive errors on memory allocation as
                appropriate.

The overcommit policy is set via the sysctl `vm.overcommit_memory'.

The overcommit percentage is set via `vm.overcommit_ratio'.



Mvh.


  Dennis Jørgensen