iMX6 Linux " /proc/sys/vm/min_free_kbytes"

[tetsuomaeda]

Hi,

Our engineers are facing a problem of the shared memory.
There is a line " echo 30000 > /proc/sys/vm/min_free_kbytes" in FreeScale BSP.
This line seems to use quite large shared memory and to cause memory problem.

Does any one know the purpose of this line and what would happen if we delete it?

As far as we are testing, we don't find problems.

Regards,

Tetsuo Maeda

[xinyu_chen]

Hi Tetsuo

You can definitely remove this configure line, as kernel would have a initial value like: 4 x sqrt(lowmem_kbytes). It is used to calculate kernel VM each zones watermark, when free memory size is below the watermark, the kswapd kernel thread would be wakeup to recliam the page cache, slab dcache, etc. This would make sure we have more free memory other than cache for new allocation. Increase this value, we would avoid OOM (out of memory) mostly. If you have not met any OOM issue, then default value is ok for you.

Thanks.

BR

Xinyu Chen

[tetsuomaeda]

Hi Eric-san,

Thank you for your response, and very sorry for my late reply because of the business trip.
I'll pass your advice to my colleague.

Thanks again for your help.

Regards,

Tetsuo Maeda