From: Gleb Natapov <gleb@redhat.com>
To: andy123 <ajs124.ajs124@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>,
qemu-devel@nongnu.org, kvm@vger.kernel.org
Subject: Re: [Qemu-devel] problems with 1G hugepages and linux 3.12-rc3
Date: Tue, 8 Oct 2013 15:23:24 +0300 [thread overview]
Message-ID: <20131008122324.GC3574@redhat.com> (raw)
In-Reply-To: <20131006024741.61cc8512@desk.lan>
Copying Andrea,
On Sun, Oct 06, 2013 at 02:47:41AM +0200, andy123 wrote:
> Hi,
>
> as the subject states, I have some problems with 1G hugepages with qemu(-vfio-git) on Linux 3.12-rc3.
>
> I start qemu like this, for example:
> "/usr/bin/qemu-system-x86_64 -enable-kvm -m 1024 -mem-path /dev/hugepages -drive file=/files/vm/arch.img,if=virtio,media=disk -monitor stdio"
> where /dev/hugepages is "hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,mode=1770,gid=78,pagesize=1G,pagesize=1G)"
> and the kernel is booted with "hugepagesz=1G hugepages=4".
> This result in lots of error message in dmesg, as seen here: https://gist.github.com/ajs124/6842823 (starting at 18:04:28)
>
> After starting and stopping multiple virtual machines, the hugepages seem to "fill up" and qemu outputs
> "file_ram_alloc: can't mmap RAM pages: Cannot allocate memory", but works anyways.
> With fill up, I mean that I can start qemu 2 time with "-m 2048" and 4 times with "-m 1024", before it fails to mmap.
>
I can reproduce huge page leak, but not oops, but they can be related.
Can you revert 11feeb498086a3a5907b8148bdf1786a9b18fc55 and retry?
> This works without any problems in 3.11.x and also with 2M hugepages (umount /dev/hugepages && mount -t hugetlbfs -o pagesize=2048k /dev/hugepages).
>
> I'm running this in arch linux and there has already been some discussion on the arch forums (https://bbs.archlinux.org/viewtopic.php?pid=1333469#p1333469) but I tried to add everything I wrote over there in this mail.
>
> In case I missed something or you need more information, I'll happily supply it in order to get this resolved.
>
> --
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--
Gleb.
next prev parent reply other threads:[~2013-10-09 12:47 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-06 0:47 [Qemu-devel] problems with 1G hugepages and linux 3.12-rc3 andy123
2013-10-08 12:23 ` Gleb Natapov [this message]
2013-10-10 0:22 ` Andrea Arcangeli
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