Bug#884938: XFS: possible memory allocation deadlock in kmem_alloc
Control: tags -1 + moreinfo
Hi Jason,
On Thu, Dec 21, 2017 at 11:30:28AM -0500, Jason Gill wrote:
> Package: src:linux
> Version: 3.16.51-3
> Severity: normal
>
> Writing a large number of files to an XFS system with a larger
> directory block size causes slow performance and kernel log errors re:
> memory allocation deadlocks.
>
> On the surface, looks very similar to this ubuntu issue:
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1382333
>
> This has been reproducible on 2/2 systems I've tried so far.
>
> xfs_info output for the affected filesystem:
> meta-data=/dev/sdf isize=2048 agcount=55, agsize=268435455 blks
> = sectsz=512 attr=2, projid32bit=1
> = crc=0 finobt=0
> data = bsize=4096 blocks=14648409600, imaxpct=1
> = sunit=0 swidth=0 blks
> naming =version 2 bsize=65536 ascii-ci=0 ftype=0
> log =internal bsize=4096 blocks=521728, version=2
> = sectsz=512 sunit=0 blks, lazy-count=1
> realtime =none extsz=4096 blocks=0, rtextents=0
>
> To reproduce, make an XFS filesystem with a large directory block size:
> # /sbin/mkfs.xfs -n size=64k /dev/sdXX
>
> Then mount the new filesystem and create a large number of small files quickly:
> $ seq -w 0 10000000 | xargs -P8 -n 256 touch
I have not looked into the fs/xfs history to find potential relevant
changes, but can you still reproduce the issue with recent kernels? In
a testsetup, but only quickly looked, I was not able to reproduce the
behaviour.
But possibly the issue could be still unfixed.
Regards,
Salvatore
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