Re: Are there some potential problems that I should be aware of if I allocate the memory which doesn't have any relation to peripheral hardwares(i.e. DMA, PCI, serial port and etc) by vmalloc() instead of kmalloc()?

On Fri, Jun 26, 2020 at 11:36:05PM +0800, 孙世龙 sunshilong wrote:

Thank you for your attention to this matter.

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Why are you having so many issues in allocating memory? I often saw the page allocation failure recently. I must resolve this problem.

What code is causing that failure by asking for memory that you do not have? Please fix that up, the core kernel should be fine.

I have no choice other than disabling these options (i.e. CONFIG-MIGRATION and CONFIG-COMPACTION) since I am using a real-time OS.

As was already stated, the use of "real-time" has nothing to do with those options, or memory allocation, or anything else here. Please do not get confused about the determinisitic operation of interrupts/scheduling vs. anything else.

It's easier to encounter such a problem since the said options are disabled.

Then fix your broken driver that is asking for so much memory on a system that does not have it. Do you have a pointer to your driver anywhere so we can review it? good luck! greg k-h