From: Alexey Skidanov <alexey.skidanov@intel.com>
To: linux-mm@kvack.org, labbott@redhat.com
Subject: Re: Possible reasons of CMA allocation failure
Date: Mon, 5 Feb 2018 15:46:13 +0200 [thread overview]
Message-ID: <d566a6df-b0d7-8ab6-69dc-ae6077cee75b@intel.com> (raw)
In-Reply-To: <10f52913-ad8b-4fd2-5e55-47aa46c48c0d@intel.com>
On 02/05/2018 12:58 AM, Alexey Skidanov wrote:
> Hello,
>
> On x86 machine with 16GB RAM installed, I reserved 1 GB area for CMA:
> [ 0.000000] cma: Reserved 1024 MiB at 0x00000003fcc00000
>
> Some time after the boot, CMa failed to allocate chunk of memory while
> there are enough contiguous pages:
>
> [ 392.132392] cma: cma_alloc: alloc failed, req-size: 200000 pages,
> ret: -16
> [ 392.132393] cma: number of available pages:
> 6@8314+9@8343+9@8375+253648@8496=> 253672 free of 262144 total pages
> [ 392.132398] cma: cma_alloc(): returned (null)
>
> What are the possible reasons for such failure (besides the pinned user
> allocated pages) ?
>
> Thanks,
> Alexey
>
After some debugging - the page migration failed because of there is the
page with _refcount 2, _mapcount -1. Seems like it's pinned?
Thanks,
Alexey
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
prev parent reply other threads:[~2018-02-05 13:45 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-04 22:58 Alexey Skidanov
2018-02-05 13:46 ` Alexey Skidanov [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d566a6df-b0d7-8ab6-69dc-ae6077cee75b@intel.com \
--to=alexey.skidanov@intel.com \
--cc=labbott@redhat.com \
--cc=linux-mm@kvack.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox