swap_pager: indefinite wait buffer
tech-lists at zyxst.net
Mon Mar 2 19:37:26 UTC 2020
On Thu, Feb 27, 2020 at 12:29:39PM +0100, Luciano Mannucci wrote:
>Since my last upgrade (to 11.3-RELASE-p6) I've noticed some messages
>in the daily security report of one of my PPC 64 virtual servers, that
>runs under KVM/Qemu, which says:
>Feb 26 20:17:53 Saguaro kernel: swap_pager: indefinite wait buffer: bufobj: 0, blkno: 1698063, size: 20480
I also see this - 12.1-stable r358260 and the load it happens with is
poudriere, but it'll only happen when building the largest packages. I have to
re-run the poudriere run. It'll eventually complete.
>and swapinfo says:
>Device 1K-blocks Used Avail Capacity
>/dev/md99 2097152 420564 1676588 20%
>/dev/md98 2097152 419352 1677800 20%
>Total 4194304 839916 3354388 20%
I also use a swapfile, but as well as that I have a 4GB swap partition. I've
had the swapfile up to 32GB and it still happens. If I turn off the swapfile,
the swap partition will fill up leading to out-of-swapspace errors. The
indefinite-wait-buffer messages only happen with a swapfile.
>Is there something I should check?
>Any kernel variables tunable via sysctl?
I haven't found a fix for this yet. I was thinking of reinstalling the system
but this time making a 32GB partition for swap (and dispensing with the
swapfile). I would have hoped that a swapfile could be used just like a swap
partition but alas it seems not. There are vm_swap tunables in sysctl but I
have no idea what they do and, as far as I can tell, appear not to be
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