From: Greg KH <greg@kroah.com>
To: "孙世龙 sunshilong" <sunshilong369@gmail.com>
Cc: Kernelnewbies@kernelnewbies.org
Subject: 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()?
Date: Sat, 27 Jun 2020 07:05:46 +0200 [thread overview]
Message-ID: <20200627050546.GC226238@kroah.com> (raw)
In-Reply-To: <CAAvDm6aZc5js0NKJZPdcTjNkKgg+3QGXLPyYaVosjgdvJcZq5w@mail.gmail.com>
On Fri, Jun 26, 2020 at 11:36:05PM +0800, 孙世龙 sunshilong wrote:
> Thank you for your attention to this matter.
>
> >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
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prev parent reply other threads:[~2020-06-27 5:06 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-26 8:30 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()? 孙世龙 sunshilong
2020-06-26 14:13 ` Greg KH
2020-06-26 15:36 ` 孙世龙 sunshilong
2020-06-26 17:22 ` Valdis Klētnieks
2020-06-27 5:16 ` 孙世龙 sunshilong
2020-06-27 5:23 ` Greg KH
2020-06-27 6:00 ` 孙世龙 sunshilong
2020-06-27 7:05 ` Greg KH
2020-06-27 5:05 ` Greg KH [this message]
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