Re: The pagedaemon evicts ARC before scanning the inactive page list
- In reply to: Alan Somers : "Re: The pagedaemon evicts ARC before scanning the inactive page list"
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Date: Thu, 20 May 2021 06:44:20 UTC
On 19/05/2021 23:28, Alan Somers wrote: > Follow-up: > All of the big inactive-memory consumers were files on FUSE file systems that > were being exported as CTL LUNs. ZFS files exported by CTL do not use any res > or inactive memory. I didn't test UFS. Curiously, removing the LUN does not > free the memory, but shutting down the FUSE daemon does. A valid workaround is > to set the vfs.fusefs.data_cache_mode sysctl to 0. That prevents the kernel > from caching any data from the FUSE file system. I've tested this on both > FreeBSD 12.2 and 13.0 . Should the kernel do a better job of reclaiming > inactive memory before ARC? Yes, but in my case it's better not to create so > much inactive memory in the first place. Thanks for everybody's help, > especially kib's tip about "vmstat -o". Nevertheless, the larger problem still exists. I can confirm it on my system and right now I am not using fusefs at all. I do, however, use some programs that like to mmap some big data a lot. The current pageout + ARC reclaim code really oppresses the ARC. I think that Kostik and Mark made some good suggestion on how that can be fixed. -- Andriy Gapon