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On Thu, 12 Apr 2012 19:30:08 -0400 |
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Richard Yao <ryao@×××××××××××××.edu> wrote: |
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> I am running Gentoo on ZFS using the kernel modules from sys-kernel/spl |
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> and sys-fs/zfs. If I put swap on ZFS, the kernel appears to deadlock |
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> when it tries to use it. I am having trouble getting a backtrace. |
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> |
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> Does anyone have any suggestions on how I could debug this? |
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> |
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If it's that easy to reproduce, I'd suggest to try it in usermode |
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linux (ARCH=um make). It's a linux kernel as unprivileged userspace |
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process. Easy to attach with gdb, add printk and etc. |
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Does not support SMP. |
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|
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- swap on FS has some optimizations which are not very well suited |
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to copy-on-write files. kernel picks file block map from filesystem |
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and tries to use it directly (code might be shared with FIBMAP |
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implementation). It's a tricky part to handle. |
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- triple-check all ZFS memory allocations go at least via GFP_NOFS |
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allocations. |
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-- |
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Sergei |
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